P -* op “4 BRIDGE ARCHITECTURE CONTAINING TWO-HUNDRED ILLUSTRA: TIONS OF THE NOTABLE BRIDGES OF THE WORLD, ANCIENT AND MODERN WITH DESCRIPTIVE, HISTORICAL AND LEGENDARY TEXT lew? WILBUR J.WATSON PUBLISHED BY WILLIAM HELBURN INC. [Seb ASIeoo lt STREET NEW YORK COPYRIGHT 1927 BY WILBUR J. WATSON Affectionately dedicated to CADY STALEY, Ph.D., LL.D. President Emeritus of Case School of Applied Science | Cleveland, Ohio I like a bridge— It cries, ‘‘“Gome on “T’ll take you there from here and here from there “And save you time and toil.” I like a bridge— It breathes romance; “There’s new adventure on the further side “And I will help you cross.” I like a bridge— It makes me think That when a worry comes, my mind will find Somewhere a friendly bridge. oo ek “Bridges ought to have the self-same qualifications we judge necessary in all other buildings, which are that they should be commodious, beautiful and lasting.” res —Andrea Palladio, 1518-1580 — “In the history of Architecture, those — ie bridges are the most attractive which are something more than mere passages for carriages and pedestrians.” —Russell Sturgis ‘ LIST OF ILLUSTRATIONS NAME THE EDWIN NATURAL BRIDGE PRIMITIVE TIMBER CANTILEVER BRIDGE OLD MASONRY ARCH BRIDGE OLD MASONRY ARCH BRIDGE OLD MASONRY SLAB BRIDGE PRIMITIVE TIMBER ARCH BRIDGE PRIMITIVE SUSPENSION BRIDGE PONTOON BRIDGE ACROSS THE GOLDEN HORN CAESAR’S BRIDGE OVER THE RHINE PONTE ROTTO. ANCIENT ROMAN BRIDGE PONTE SISTO. ANCIENT ROMAN BRIDGE PONTE QUATTRO CAPI. ANCIENT ROMAN BRIDGE PONTE ST. ANGELO. ANCIENT ROMAN BRIDGE PONTE MOLLE. ANCIENT ROMAN BRIDGE PONTE DI AUGUSTO. ANCIENT ROMAN BRIDGE PONT DU GARD. ROMAN AQUEDUCT BRIDGE PONT FLAVIEN. ROMAN MEMORIAL BRIDGE TRAJAN’S BRIDGE OVER THE RIVER TAGUS TOWER AT CENTER OF ALCAN’TARA BRIDGE ROMAN AQUEDUCT BRIDGE. GENERAL VIEW ROMAN AQUEDUCT BRIDGE ROMAN AQUEDUCT BRIDGE BRIDGE OF ST. BENEZET VALENTRE BRIDGE MEDIEVAL BRIDGE OF BRICK OLD LONDON BRIDGE PUENTE DE SAN MARTIN. GENERAL VIEW PUENTE DE SAN MARTIN. DETAILS PUENTE DE SAN MARTIN. DETAILS PUENTE DE ALCANTARA. GENERAL VIEW LOCATION UTAH BHUTAN, ASIA CHUNG-KING, CHINA PU’TO’SHAN, CHINA HANCHOU, CHINA CASHMERE, ASIA SZE-CHUAN, CHINA CONSTANTINOPLE ROME ROME ROME ROME ROME RIMINI, ITALY NIMES, FRANCE ST. CHAMAS, FRANCE ALCAN’TARA, SPAIN SEGOVIA, SPAIN SEGOVIA, SPAIN SEGOVIA, SPAIN AVIGNON, FRANCE CAHORS, FRANCE MONTAUBAN, FRANCE LONDON, ENGLAND TOLEDO, SPAIN TOLEDO, SPAIN TOLEDO, SPAIN TOLEDO, SPAIN PLATE XVIII XIX XXII XXIII XXIV XXV XXVI XXVII XXVIII PAGE 99 22, ILLUSTRATIONS NAME LOCATION PUENTE DE ALCANTARA. DETAILS ~~ | oP “TOLEDO, SPAIN - BRIDGE OVER THE RIVER MINHO ORENSE, SPAIN ANCIENT BRIDGE ae DOLCEACQUA, ITALY BRIDGE OF MARTORELLI oar BARCELONA, SPAIN PONTE VECCHIO FLORENCE, ITALY. KARLSBRUCKE. GENERAL VIEW PRAGUE KARLSBRUCKE. TOWER PRAGUE BRIDGE OVER THE TICINO PAVIA, ITALY PONTE DELLA PIETRA. GENERAL VIEW VERONA, ITALY PONTE DELLA PIETRA. DETAIL VERONA, ITALY PUENTE DE PIEDRA ZARAGOSSA, SPAIN CASTELVECCHIO VERONA, ITALY THE TWA BRIGS O’AYR AYR, SCOTLAND THE AULD BRIG 0’DOON SCOTLAND OLD MASONRY BRIDGE . _ BIDDEFORD, ENGLAND PONTE DI RIALTO VENICE, ITALY PONTE DI SOSPIRE . VENICE, ITALY PONTE DELLA TRINITA FLORENCE, ITALY PARK BRIDGE CHATSWORTH, ENGLAND PONT NEUF PARIS PONT ROYAL PARIS PONT ROYAL PARIS PONT ST. LOUIS PARIS PANORAMA OF BRIDGES PARIS PONTE DI MEZZO - PISA, ITALY THE OLD BRIDGE PONT DE LA CONCORDE PARIS WATERLOO BRIDGE LONDON NEW LONDON BRIDGE AS BUILT LONDON “THE OLD BRIDGE” HEIDELBERG PONT Y PRIDD WALES | BRITANNIA BRIDGE WALES PONT DE LA ARCHEVECHE TOULOUSE, FRANCE PARIS ILLUSTRATIONS NAME PONT AU CHANGE PONT D’ALMA PONT ALEXANDRE III PONT D’AUTEUIL SEJOURNE’ BRIDGE OVER THE PEDROUSE BRIDGE OVER THE PETRUSSE PONTE SOLFERINO COULOUVRENIER BRIDGE OLD BRIDGE OVER THE AGOUT NEW BRIDGE OVER THE AGOUT HANNIBAL BRIDGE OVER THE VULTURNE THE EDWARD THE SEVENTH BRIDGE PONT ANTOINETTE RAILROAD MASONRY ARCH RAILWAY BRIDGE OVER THE LOIRE RAILWAY BRIDGE OVER THE MOSELLE THE FREDERIG AUGUST BRIDGE BRIDGE OVER THE TAJO “HIGH BRIDGE” CABIN JOHN ARCH MEMORIAL BRIDGE OVER THE CONNECTICUT RIVER MASONRY BRIDGE OVER SUSQUEHANNA RIVER STONE MASONRY BRIDGES STONE MASONRY BRIDGES MASONRY BRIDGE IN ROCKEFELLER PARKWAY MASONRY BRIDGE IN ROCKEFELLER PARKWAY VITTORIO EMANUELE II BRIDGE COVERED TIMBER BRIDGE OVER MUSKINGUM RIVER SOUTHWARK BRIDGE SOUTHWARK BRIDGE WESTMINSTER BRIDGE EL KANTARA EADS BRIDGE OVER THE MISSISSIPPI LOCATION PARIS PARIS PARIS PARIS FRANCE LUXEMBURG PISA GENEVA LAVAUR, FRANCE LAVAUR, FRANCE ITALY KEW, ENGLAND TARN, FRANCE VORAILBERG, AUSTRIA ORLEANS, FRANCE LORRAINE PLAUEN RONDA, SPAIN NEW YORK WASHINGTON, D. C. HARTFORD, CONNECTICUT HARRISBURG, PENNSYLVANIA ELYRIA, OHIO BEREA, OHIO CLEVELAND, OHIO CLEVELAND, OHIO ROME, ITALY ZANESVILLE, OHIO LONDON, ENGLAND LONDON, ENGLAND LONDON, ENGLAND CONSTANTINE, ALGERIA ST. LOUIS, MISSOURI PLATE LXII LXIII LXIV LXV LXVI LXVII LXVIII LXIX LXX LXXI LXXII LXXIII LXXIV LXXV LXXVI LXXVII LXXVIII LXXIX LXXX LXXXI LXXXII LXXXIII LXXXIV LXXXV LXXXVI LXXXVII LXXXVIII LXXXIX XC XCI Xcil XCIII XCIV PAGE 118 ILLUSTRATIONS NAME WHIPPLE TRUSS BRIDGE WASHINGTON BRIDGE GARABIT VIADUCT STEEL ARCH BRIDGE OVER THE RHINE STEEL ARCH BRIDGE OVER THE AAR STEEL ARCH BRIDGE OVER THE RHINE STEEL ARCH BRIDGE OVER THE RHINE STEEL ARCH BRIDGE OVER THE NIAGARA RIVER HELL GATE BRIDGE LONGFELLOW BRIDGE LONGFELLOW BRIDGE, DETAILS RAILWAY BRIDGE OVER STREET STEEL ARCH BRIDGE STEEL ARCH BRIDGE STEEL ARCH BRIDGE FORTIETH STREET BRIDGE SIXTEENTH STREET BRIDGE OLD SUSPENSION BRIDGE TELFORD’S BRIDGE KETTENBRUCKE ELIZABETH BRIDGE ROEBLING’S BROOKLYN BRIDGE THE WILLIAMSBURG BRIDGE THE MANHATTAN BRIDGE DELAWARE RIVER BRIDGE DELAWARE RIVER BRIDGE, DETAIL RECENT SUSPENSION BRIDGE SEVENTH AVENUE BRIDGE QUEENSBORO BRIDGE FORTH BRIDGE ST. LAWRENCE RIVER BRIDGE CANTILEVER BRIDGE OVER THE MISSISSIPPI RIVER BRIDGE OVER STREET LOCATION UNITED STATES NEW YORK, N. Y. FRANCE BONN, GERMANY BERNE, SWITZERLAND RUDESHEIM, GERMANY COLOGNE, GERMANY NIAGARA FALLS, NEW YORK NEW YORK, N. Y. BOSTON, MASSACHUSETTS BOSTON, MASSACHUSETTS CLEVELAND, OHIO CLEVELAND, OHIO CHAGRIN FALLS, OHTO WORMS, GERMANY PITTSBURGH, PENNSYLVANIA PITTSBURGH, PENNSYLVANIA NEWBURYPORT, MASS. MENAI STRAIT, WALES BUDAPEST, HUNGARY BUDAPEST, HUNGARY NEW YORK, N. Y. NEW YORK, N. Y. NEW YORK, N. Y. PHILADELPHIA, PENNSYLVANIA PHILADELPHIA, PENNSYLVANIA COLOGNE, GERMANY PITTSBURGH, PENNSYLVANIA NEW YORK, N. Y. SCOTLAND QUEBEC, CANADA THEBES, ILLINOIS LONDON PLATE XCV XCVI XCVII XCVIII XCIX C cl cVI CVI-B cVII CVITI CIX CXVI CXVII CXVII CXIX CXX CcXXI IXXIT CXXIII CXXIV CXXV PAGE 155 156 177 179 181 182 183 184 185 186 189 190 191 192 193 ILLUSTRATIONS NAME RAILWAY BRIDGE OVER THE HUDSON RIVER BRIDGE. B. & O. R. R. BRIDGE OVER THE RHINE STEEL RAILWAY BRIDGE OVER THE RHINE BRIDGE OVER THE RHINE RAILWAY BRIDGE OVER EAST 30TH STREET CONNECTICUT AVENUE BRIDGE CONNECTICUT AVENUE BRIDGE WALNUT LANE BRIDGE ROCKY RIVER BRIDGE CHERRY STREET BRIDGE CHERRY STREET BRIDGE CHERRY ST. BRIDGE. DETAIL OF PROPOSED TOWER CONCRETE HIGHWAY BRIDGE KING AVENUE BRIDGE KING AVENUE BRIDGE. DETAILS THIRD STREET BRIDGE THIRD STREET BRIDGE. DETAIL BROAD STREET BRIDGE CONCRETE HIGHWAY BRIDGE CONCRETE HIGHWAY BRIDGE WILLOUGHBY BRIDGE. DETAIL OF RAILING CONCRETE RAILWAY BRIDGE MAYO’S BRIDGE OVER THE JAMES RIVER MAYO’S BRIDGE OVER THE JAMES RIVER CONCRETE VIADUCT OVER THE CUYAHOGA RIVER RAILROAD BRIDGE OVER THE SUSQUEHANNA RIVER ISLAND PARK BRIDGE LONG SPAN CONGRETE BRIDGE ACROSS THE SEINE CONGRETE VIADUCT ON D., L. & W. R.R. CONCRETE VIADUCT ON D., L. & W. R. R. WASHINGTON STREET MEMORIAL BRIDGE LOCATION CASTLETON, NEW YORK HAVRE DE GRACE, MARYLAND MAYENCE, GERMANY COLOGNE, GERMANY COBLENZ, GERMANY CLEVELAND, OHIO WASHINGTON, D. GC. WASHINGTON, D. C. PHILADELPHIA, PENNSYLVANIA CLEVELAND, OHIO TOLEDO, OHIO TOLEDO, OHIO TOLEDO, OHIO ALLENTOWN, PENNSYLVANIA COLUMBUS, OHIO COLUMBUS, OHIO COLUMBUS, OHIO COLUMBUS, OHIO COLUMBUS, OHIO WILLOUGHBY, OHIO WILLOUGHBY, OHIO WILLOUGHBY, OHIO WILLOUGHBY, OHIO RICHMOND, VIRGINIA RICHMOND, VIRGINIA AKRON, OHIO HARRISBURG, PENNSYLVANIA DAYTON, OHIO PARIS TUNKHANNOCK, PENNSYLVANIA DELAWARE WATER GAP, PENNSYLVANIA WILMINGTON, DELAWARE PLATE CXXVI CXXVII CXXVIIL CXXIX CXXX CXXXI CXXXII CXXXIII CXXXIV CXXXV CXXXVI CXXXVII CXXXVIII GXXXIX CXL CXLI CXLIL CXLIII CXLIV CXLV CXLVI CXLVIL CXLVILI CXLIX CL CLI cLII CLIT PAGE 194 ILLUSTRATIONS NAME WASHINGTON STREET MEMORIAL BRIDGE WASHINGTON STREET MEMORIAL BRIDGE Q STREET BRIDGE OVER ROCK CREEK PARK BRIDGE OVER THE MONONGAHELA RIVER CABRILLO BRIDGE CAPPELEN BRIDGE OVER THE MISSISSIPPI RIVER ROBERT STREET BRIDGE OVER THE MISSISSIPPI RIVER ROBERT STREET BRIDGE OVER THE MISSISSIPPI RIVER. DETAIL BRIDGE OVER MERRIMAC RIVER PONT BUTIN PONT DE MALLING PONTE CAVOUR PONTE UMBERTO WESTCHESTER COUNTY PARK BRIDGE FRANCIS SCOTT KEY BRIDGE CONCRETE BRIDGE—STATE HIGHWAYS CONCRETE BRIDGE—STATE HIGHWAYS CONCRETE BRIDGE—STATE HIGHWAYS CONCRETE RAILWAY BRIDGE OVER STREET CONCRETE RAILWAY BRIDGE OVER STREET RAILROAD BRIDGE CONCRETE BRIDGE OVER WEST CANADA GREEK CONCRETE SLAB BRIDGE SMALL GONGRETE AND BRICK BRIDGE CONCRETE BRIDGE ON FIFTH STREET CONCRETE BRIDGE ON “D” STREET CONCRETE BRIDGE CONGRETE BRIDGE SUMMIT STREET BRIDGE DETAIL OF LAMP POST MEMORIAL BRIDGE SMALL PARK BRIDGE LOCATION WILMINGTON, DELAWARE WILMINGTON, DELAWARE WASHINGTON, D. C. FAIRMONT, WEST VIRGINIA SAN DIEGO, CALIFORNIA MINNEAPOLIS, MINNESOTA ST. PAUL, MINNESOTA ST. PAUL, MINNESOTA HAVERHILL, MASSACHUSETTS GENEVA, SWITZERLAND LORRAINE ROME ROME SCARSDALE, NEW YORK WASHINGTON, D. C. CALIFORNIA CALIFORNIA CALIFORNIA CLEVELAND, OHIO CLEVELAND, OHIO RICHMOND, VIRGINIA HERKIMER, NEW YORK NIAGARA FALLS, ONTARIO CINCINNATI, OHIO LYNCHBURG, VIRGINIA LYNCHBURG, VIRGINIA JACKSONVILLE, FLORIDA NORTH GAROLINA WARREN, OHIO WARREN, OHIO CHESTER, PENNSYLVANIA MONTCLAIR, NEW JERSEY PLATE CLIV CLV CLVI CLVIL CLVIII CLIX CLX CLXI CLXII CLXIII CLXIV CLXV CLXVI CLXVII CLXVIII CLXIX CLXX CLXXI CLXXIT CLXXIII CLXXIV CLXXV CLXXVI CLXXVII CLXXVIII CLXXIX CLXXX CLXXXI CLXXXII CLXXXILIL-A 262 — a ILLUSTRATIONS NAME SMALL PARK BRIDGE SMALL CONCRETE HIGHWAY BRIDGE SMALL CONCRETE ARCH BRIDGE A UNIQUE BRIDGE PORTAL CONCRETE FOOT BRIDGE WITH BRICK PANELS FINDLAY STREET BRIDGE HILLIARD ROAD BRIDGE DETAIL OF CONCRETE BRIDGE DETAIL OF STAIRWAY DETAIL OF RAILING. C. A. P. TURNER, ENGINEER CHARLES RIVER BRIDGE. DETAIL MATANZAS RIVER BRIDGE DOUBLE SWING BRIDGE THE TOWER BRIDGE THE ANACOSTIA BRIDGE THE CHERRY STREET BRIDGE OVER THE MAUMEE RIVER BASCULE SPAN OF ARLINGTON BRIDGE MICHIGAN AVENUE BRIDGE WEST MADISON STREET BRIDGE FRANKLIN STREET BRIDGE LOCATION MONTCLAIR, NEW JERSEY PIEDMONT, CALIFORNIA PIEDMONT, CALIFORNIA RIVERSIDE, CALIFORNIA CINCINNATI, OHIO DAYTON, OHIO CLEVELAND, OHIO BAVARIA GLENS FALLS, NEW YORK BOSTON, MASSACHUSETTS ST. AUGUSTINE, FLORIDA WILHELMSHAVEN, GERMANY LONDON WASHINGTON, D. C. TOLEDO, OHIO WASHINGTON, D. C. CHICAGO, TLLINOIS CHICAGO, ILLINOIS CHICAGO, ILLINOIS PLATE PAGE CLXXXIL-B 263 CLXXXIV-A 264 CLXXXIV-B 265 CLXXXV 266 CGLXXXVI 267 CLXXXVII 268 CLXXXVIII 269 CLXXXIX 270 210 208 CXC 270 CXCI 271 CXCIL 272 CXCIII 273 CXCIV 274 CXCV 275 CXCVI 276 CXCVIL 207 CXCVIITI 278 CXCLX 279 « raynga cannes SEGOVIA, SPAIN—DETAIL OF ROMAN AQUEDUCT—98 A.D. PHOTO BY LOUIS LA BEAUME Pie Gh ARCHITEOCLURE “ik late Daniel H. Burnham once defined archi- js tecture as “the art of creating an agreeable 4 } form.” Bridge architecture then may be defined kta as the art of creating bridges agreeable in form; fan art, of course, that must conform to the re- ve \ » quirements of the science of bridge engineering. . Granting that human happiness is greatly . 848 enhanced by beautiful and pleasing surround- ings, it is highly desirable that utilitarian structures such as bridges should be as pleasing to the eye as it is practicable to make them and that there should be greater collaboration between the architect and the engineer with a realization on the part of each that science without art is apt to be unattractive and art without science inefficient. The purpose of this work is to illustrate the art of good bridge design, both as to composition and detail, as exemplified by ancient and modern bridges, utilizing selected photographs for this purpose. The text includes descriptions of many of the bridges illustrated, some historical data and considerable literary and legendary lore, all of which the author hopes will be found of interest to the lay reader, as well as to the engineer and the architect. With this object in view, tech- nical terms have been avoided as much as possible and technical data for the most part has been omitted. The data contained herein has been gathered from many sources, but largely from the books listed under “Bibliography.” The photographs BRIDGE ARCHITECTURE | have been collected over a period of years from many sources. Wherever possible, full credit has been given to the designers of the structure illus- trated. and also to the source from which the photograph was obtained. The reader will note that many of the best designed bridges of the Modern Period are those in the design of which engineers and architects collaborated. Critical quotations from various writers, ancient and modern, have been freely used in this text, and the reader will note that there is con- siderable disagreement among these writers on many questions of archi- tectural design, such as the propriety of using the classical architectural motives as ornamental features on bridges. While a small amount of original criticism of certain designs and tendencies will be found in the text, it has been the author’s aim to bring together, under a single cover, a considerable number of illustrations of selected designs for critical study by the reader. The bridge is one of the most important of architectural develop- ments, and it is with the hope of quickening interest in the subject that this volume has been prepared. Special acknowledgment for valuable assistance is made to Professor F. H. Neff, Professor F. H. Constant, Professor Geo. 5. Beggs, Mr. Clement E. Chase, all members of the American Society of Civil Engi- neers. to Mr. A. T. North, member of the American Institute of Archi- tects. and to Mr. William Ganson Rose, editorial counsellor. [ 18 | —— a eo ee " om Sar eae ee ae ee a a ae BRIDGE ARCHITECTURE CLASSIFICATION BY TYPES BRIDGES ARE CONSIDERED HEREIN AS DIVIDED INTO FIVE TYPES, EACH TYPE UTILIZING A DIFFERENT MECHANICAL PRINCIPLE AS THE BASIS OF ITS DESIGN, AS FOLLOWS: THE ARCH The Arch, the mechanical principle of which is that of a curved structure, the elements depending upon the com- pressive strength of the material used. The corresponding example in nature is the natural stone arch. THE SIMPLE BEAM The Simple Beam, depending primarily upon the bending strength of the material. The natural example is that of the fallen tree spanning a stream. THE SUSPENSION The Suspension, or cable bridge, utilizing the simple prin- ciple of the cord in direct tension, as illustrated in nature by the swinging vine, utilized by monkeys in passing from one tree to another. [19 ] BRIDGE ARCHITECTURE THE CANTILEVER The Cantilever, making use of mechanical principles similar to those of the simple beam, but requiring an anchorage at one end. Quite probably, primitive man discovered the principle at a very early stage of his development, and made use of it to construct longer spans than he was able to build with simple beams. THE TRUSS The Truss, requiring the use of connected members, some in compression, some in tension, and some as simple beams, seems to have been utterly beyond the comprehen- sion of the barbarian, and, in fact, belongs almost exclu- sively to modern civilization. CLASSIFICATION BY PERIODS ISTORICALLY, bridges are convenient- ly assigned to six periods: FIRST PERIOD The Ancient Period, preceding the Roman Era, during which most bridges, in Europe, at least, were of the beam type. Arch bridges were probably built in China prior to the Roman Era, and the arch was used by the ancient Egyptians in other constructions. SECOND PERIOD The Roman Period, during which the Ro- mans introduced the extensive use of the arch principle, dating from 300 B. C. to 300 A. D., covering a period of about 600 years. THIRD PERIOD The Middle Ages in Europe, from the elev- enth to the sixteenth centuries, characterized chiefly by the construction of massive, more or less crudely designed and executed arches of masonry, but including also many arches of bold and slender proportions. During this period, practically all culture centered in the religious orders, and, there- fore, most of the bridges were built by monks. During this period finer work was probably being done by the Chinese. Was FOURTH PERIOD The Renaissance in Europe, occurring dur- ing the sixteenth and seventeenth centuries, exhibited much greater refinement of both design and construction. It is worthy of note that up to the eighteenth century, no distinction was made between the architect and the engineer, the master builders of those days devoting their talents to the design of both buildings and bridges. FIFTH PERIOD The Eighteenth Century, including the first quarter of the nineteenth, during which the masonry arch reached its greatest perfec- tion, and engineers, skilled and specializing in bridge construction, made their appear- ance. Prominent among these first bridge engineers were the Rennies in England and Perronet in France. SIXTH PERIOD The Modern Period, beginning with the advent of the railroad about 1830, and characterized by the utilization of all of the five basic types, but more especially by the perfection of the truss type, due to the avail- ability of structural iron and steel. | ARCHITECTURE BRIDGE WUOK MAN ‘SOLOHd GTHOM AGIM SAWIL WOUd OLOHd ADGINd TVYNLVN NIMGA AHL—-AVLO—I ALVId ee - he) TURE | A PARC HT Eat Brel) GE NOGNOT ‘ALIHM AGNAWIO NHOL Ad OLOHd LOOA-0€I—ADGINd YHAATILNVO YHANIL AALLINTYd—VISV “(NVLOHE@—IT ALY Id HITECTURE ARG BRIDGE HOWNHO TVdOOSIdd LSIGOHLAW AHL dO SHIONADY SOLAUHS GTHOM WOU OLOHd NMONYMNO AOV—HOUV AYNOSVN GAYAHAOO—VNIHD “ONIY-DONOHD—IIT ALV 1d TeV TTT TRTIT OOOO “aa ae" ec —egearere! BRIDGE ARCHITECTURE OLAd AO GNWISI GHYOVS NNVWHOSYHOd LSNYA A . VNIHO ANOSaYu ALI, | WOYUd OLOHd ‘ ‘MAVT JO NIVY AHL JO AYALSVNOW AHL OL ADGIYA—VNIHD ‘NVHS,OLOd—AL ALVWTd r, | Ue C i) by f ARCH TT I BRL DIGE NNVAHOSUSO@ ISNYA , ‘VNIHO andsauasota,, woud HOCH AVIS ANOLS—VNIHO ‘QNOHONVH—A BLY Id ARCHITECTURE BRIDGE MYOA MAN SHOLTAYHS OLOHd SHUAHSITANd AW LHDIWAdOO UVOVNIYS LY HAA WWIAHE AHL YHAO ADGINA HOUV YAAWLL—VISV ‘AYAINHSVO —IA ALV'Td [ 27 BRIDGE ARCHITECTURE HOLI4 “d “LAOU AM OLOHA NVOHO-AZS LV AOC NOISNHdSAS—VNIHO—IIA ALWId BRIDGE ARCHITECTURE “OV DYUAANYON-DYNASDOV MIMAVANANTHOSVA WOWd OLOHd Ad XL NOOLNOd—NYOH NACGTIOD AHL YHAO AOCGIYA—HWIdONILNVLSNOD—ITA ALY Td I. THE ANCIENT PERIOD Ancient Cantilever Bridges in Asta RIDGES of this type are common today in Central Asia, and have been in exis- tence since ancient times. The timber parts, of course, require periodic replacement, but the design has probably remained un- changed for ages. Plate 11 shows a bridge in Bhutan, which is of unknown age, but reputed to be very old. The span of this particular bridge is 130 feet. The photograph was taken by John Claude White. Anctent Chinese Arches Many fine stone arches are to be found in China; and while little definite data is avail- able regarding them, and especially their ages, enough is known to prove that many of them are perhaps over 2000 years old, although some of those herein illustrated are probably of comparatively recent date, but may be con- sidered as representative of an art that is, in itself, undoubtedly ancient. Some of these structures are beautiful and demonstrate that the Chinese were familiar with many refine- ments of the art long before these refinements were practiced in Europe. For instance, the projecting extradosal course, which appears first in European bridge architecture about the fifteenth century, was used in an old structure at Chung-King, shown in Plate 1. Has Europe anything that surpasses the simple beauty of the structure at Pu’to’shan, photographed by Ernst Boerschmann and illustrated in his “Picturesque China’? (Plate Iv.) Some of these old Chinese masonry bridges are quite long. Boerschmann shows one com- prising fourteen arches, and similar bridges are described in the writings of Marco Polo, who visited China in the thirteenth century A. D. The Chinese have also some interesting bridges of other types than the arch. For in- stance, there is a bridge of stone slabs on stone piers at Hanchou, the piers decorated with carved heads of animals. (Plate vy, Boersch- mann.) There also exist in Eastern Asia good ex- amples of bridges of the timber arch type sup- ported on stone piers, as shown by a bridge in Cashmere, Plate vI, and the suspension type, illustrated by a bridge in Northern Sze-Chuan, built of bamboo cables about eight inches in diameter, Plate vil. In Japan there are many beautiful bridges of timber, most of them utilizing the beam principle, -and renewed as required. The rebuilt struc- ture is usually an exact reproduction of the old, thus perpetuating the design, which may be ancient, while the existing structure is recent. Little is known regarding the ancient bridges of Western Asia. It is supposed that brick arch bridges spanned the Euphrates at Babylon, and a writer asserts that one of these had a span of 660 feet, a statement that seems [ 30 | BRIDGE ARCHITECTURE improbable, and not to be taken seriously. Some early writers and travelers must have possessed vivid imaginations. George Semple, writing in 1776, describes a stone bridge in China, which he calls the Bridge over the River Saffrany, spanning 600 feet in a single arch, and having a height from its foundation to the top of the parapets of 750 feet and which was known to travelers as the Flying Bridge. It must have flown away. There are old bridges in Persia, but definite information regarding them is not obtain- able. Some were undoubtedly Roman in ori- gin. One at Dizful, over the river Diz, has a length of 1250 feet, contains twenty pointed arches, and is variously dated from 350 B.C. to 300 A.D. Many of these old Persian bridges are built of brick and reflect the influence of Byzantine architecture. Ancient Pontoon or Floating Bridges Herodotus tells us that Xerxes built a pon- toon bridge over the Hellespont to facilitate his invasion of Greece in the year 480 B.C. According to the noted historian, this bridge was double, consisting of one line of 360 boats and another of 314, the construction being quite similar to the military pontoon bridges of the present day, extensively used in the World War. Herodotus states that it took the Persians seven days and nights to pass over it, march- ing in two steady streams. The width of the straits at this point is about a mile, which would correspond to a spacing of the boats of about fifteen feet. Similar bridges are men- tioned by Homer, who lived in the ninth century B.C., and Xenophon describes one he built over the Tigris in the “Retreat of the Ten Thousand.” These pontoon bridges belong to the beam type, the stationary piers being replaced by boats or pontoons, which support the ends of the beams that carry the roadway plat- form. They are crude, requiring but little architectural skill. While the pontoon type is usually employ- ed for temporary purposes only, some exist- ing structures have served for very long peri- ods, with more or less frequent repairs and rebuilding. One of the most important of such bridges is that over the Golden Horn at Con- stantinople, recently rebuilt, and illustrated by Plate vim. Ancient Pile or Trestle Bridges The Sublician is supposed to have been the first bridge over the River Tiber constructed by the Romans, and was famous as the bridge defended so heroically by Horatius Cocles, who single-handed held the Etruscan army at bay while his comrades destroyed the bridge behind him. As a matter of fact, it was a crude pile and beam structure of tim- ber, the precise details of the construction being a matter of conjecture. Such timber pile bridges are doubtless of ancient origin, as the pre-historic lake dwellers of Europe used a similar construction on which to build their rude huts, which were accessible only by means of a pile and beam bridge connect- ing with the land, the ancient prototype of the modern timber trestle so familiar to us all. At one time, about 620 B.C., the Sublician Bridge was rebuilt by the Chief Priests, to whom its maintenance seems to have been [ 31 | BRIDGE ARCHITECTURE entrusted. It is said that they thereupon assumed the title of pontifices, a title which was appropriated and perpetuated by the Christian Church and is supposed to be the origin of the title of the Popes, The Holy Pontiffs. According to the Encyclopedia Britannica, the word ‘‘pontifex”’ is evidently derived from ‘pons’ (bridge), and “‘facere,’ and is be- lieved to have a connection of some kind with the sacred bridge over the Tiber known as the Pons Sublicius, although this is disputed. The Collegium of the Pontifices was the most important priesthood of Rome. The head of the order came to be known, under the Re- public, as the Pontifex Maximus, and under the Empire this title was assumed by the Emperors themselves. With the decay of the Empire and rise of the Christian Church to temporal power, this title naturally fell to the Popes. So the highest religious title in Christendom probably is derived from, or is synonymic with, that of the humble bridge builder. The Pons Sublicius seems never to have been rebuilt in stone, but was always re- tained as a timber bridge, possibly for senti- mental reasons. Caesar's Bridge over the Rhine The military bridge which Julius Caesar said he built across the Rhine in ten days’ time has been a model for timber pile bridges ever since. The design consisted of pile piers which were protected by ice breakers formed of groups of three piles. These pile piers were capped with rough timbers which supported the lintels or beams, also of rough timbers, [ 3: and these in turn carried the flooring, a de- scription easily recognized as applying to the typical modern timber trestle bridge. This bridge was about 124 meters (40 feet) wide and 425 to 525 meters (1300 to 1600 feet) in length. The individual spans were approx- imately 614 to 8 meters (20 to 25 feet). The work is thus described in Caesar’s Commentaries, the dimensions being given in Roman feet, only slightly different from the modern unit of the same name. ‘He joined together at the distance of two feet, two piles each a foot and a half thick, sharpened a little at the lower end, and pro- portioned in length to the depth of the river. After he had, by means of engines (pile driver or any other machinery), sunk these into the river and fixed them at the bottom, and then driven them in with rammers, not quite perpendicularly like a stake, but bending forward and sloping, so as to incline in the direction of the current of the river; he also placed two other piles opposite to these, at the distance of forty feet lower down, fastened together in the same manner but directed against the force and current of the river. Both these, moreover, were kept firmly apart by beams two feet thick (the space which the binding of the piles occupied), laid in at their extremities between two braces on each side; and in consequence of these being in different directions and fastened on sides the one oppo- site to the other, so great was the strength of the work, and such the arrangement of the materials, that in proportion as the greater body of water dashed against the bridge, so much the closer were its parts held fastened together. These beams were bound together BRIDGE ARCHITECTURE by timber laid over them in the direction of the length of the bridge and were then covered over with laths and hurdles; and in addition to this, piles were driven into the water obliquely, at the lower side of the bridge, and these serving as buttresses, and being con- nected with every portion of the work, sus- tained the force of the stream; and there were others also above the bridge at a moderate distance; that if trunks of trees or vessels were floated down the river by the barbarians for the purpose of destroying the work, the violence of such things might be diminished by these defences, and might not injure the bridge. Within ten days after the timber began to be collected the whole work was completed, and the whole army led over.”’ Like most military bridges, this famous structure was short lived, being cut down by order of Caesar himself only eighteen days later, having served its purpose. Without doubt, the Roman armies built many such structures. The pile or trestle bridge, like the pontoon type, admits of but slight architectural treat- ment, although many such structures have FROM “CAESAR’S COMMENTARIES,” KELSEY been embellished with more or less artistic timber railings, and, when of rustic design, used for small and light bridges, can be made very attractive. Trajan’s Bridge over the Danube This was one of the most famous of the early Roman Bridges, and while neither an accurate description nor sufficient ruins for recon- structing it have comedown to us, it is known to have consisted of twenty spans of timber arches, supported upon masonry piers, and was therefore the first notable example of the use of this combination. The ruins of thirteen piers are still visible at the site, which is just above the “Iron Gate” of the Danube. The design is illustrated on the Arch of Trajan at Rome, and attributed to one Apol- lodorus of Damascus. This bridge was built by Trajan in order that he might the more readily get at the barbarians to the north of the Danube, and it is of interest, historically, to note that a little later it was demolished by order of the Emperor Hadrian because, it is said, the tables had been turned and the barbarians were using it in order to get back at the Romans. Ancient records state that this proj- ect was completed in a single season. These timber bridges constructed by the Romans were only copies of types that doubt- less were common in Europe as well as in Asia for many centuries preceding the Roman era and they therefore belong, historically, to ancient times. The true Roman Era in bridge building began with the use of the masonry arch, which the Romans developed to a high degree [ 33 | BRIDGE ARCHITECTURE of perfection. Nevertheless, the typical Roman bridge was doubtless always a timber pile trestle, even in the days of the Empire, and, that these structures were not always well built or safe is shown by many references to them in Roman literature, such as the follow- ing human quotation from Catullus: “OQ, Colonia, you who desire to sport on a long bridge and are prepared to hold your feasts, but you fear the shaky legs of the little bridge standing on second hand sticks, lest it would tumble flat, and lie in the deep marsh. O, Colonia, give me this gift, of a great laugh, if a good bridge on which the sacred feasts of the Saturnalia might be held is given to you for your games. I wish that a certain fellow townsman of mine might fall from your bridge head over heels into the mud and in truth where the lake and the brimy, stinking swamp is darkest and deep- est.”’ Catullus (87-55 B. C.) It seems strange that the Greeks, who de- veloped an architecture so beautiful and per- fect that it has remained the wonder of all succeeding ages, built no bridges worthy of mention. The answer is to be found in the fact that the Greeks built no great highways; they were a sea-faring people and their one great highway was the Mediterranean Sea, on the shores of which they founded their beautiful cities, and over the waters of which they maintained intercity communication. Il. THE ROMAN PERIOD Roman Bridges over the Tiber at Rome There are in existence today, wholly or par- tially intact, six old bridges over the Tiber dating back to Roman times, the Ponte Rotto, the Ponte Sisto, the Ponte Quattro Capi, the Ponte St. Angelo, the Ponte Molle and the Ponte Cestius. The Ponte Rotto, known to the Romans as the Pons Aemilius (named for the Pontifex Maximum M. Aemilius Lepidus) and to Pal- ladio'- as the Pons Palatinus, is the most ancient of existing Roman Bridges, but the present ruins of the arches are believed, in the absence of historical records, to be replace- ments, at least in part, of the original spans. The arches have spans of 24 meters* and the material used was peperino and tufa for the arches, with a facing of travertine. These Same materials were used for the other exist- *One meter equals 3.28 feet. ing Roman bridges. (Plate Ix.) The Ponte Sisto as it now exists is believed to have been rebuilt upon the foundations of the old Pons Aurelius or Palatine Bridge by Pope Sixtus IV about 1480, so that probably only parts are Roman. (Plate x.) The present Ponte Quattro Capi is the ancient Bridge of Fabricius, built in the year 62 B. C. and is practically intact as then - built. The modern name is derived from an emblem representing the four-headed Janus, carved on the bridge parapet. The arches have spans of 25 and 34 meters and the width is 15 meters. The structure was repaired in 1680. The two segmental arches spring from the water level and the spandrel over the center pier is pierced by a large arched opening flanked by two pilasters carried to the cop- [ 34 ] BRIDGE ARCHITECTURE ing line. There is a pleasing contrast between the large stones of the arch rings and parapet and the small material used for the spandrel walls. (Plate xt.) The Ponte St. Angelo is the Pons Aelius of Roman times, built by the Emperor Hadrian in 134 A. D., and consisted of eight arches having a maximum span of 20 meters. The present parapets were added in the seven- teenth century and contain ten statues by Bernini, the architect who designed the great Colonnade of St. Peter’s. The modern bridge has but five arches admitted to be part of the original construction. These arches have projecting extradosal courses and carefully coursed masonry throughout. (Plate XII.) The Pons Milvius (modern Ponte Molle), located on the Flaminian Way, was built originally in 109 B. G., by M. Aemilius Seaurus, but only parts of the present struc- ture are believed to be the original work. (Plate XIIT.) The Pons Cestius (modern Ponte St. Bar- tolomew), built in 43 B. C. and rebuilt about 370 A. D., is in good condition and contains much of the original masonry in spite of numerous restorations. [t consists of a single arch. Roman Bridge at Rimini, Italy This is a fine example of Roman bridge build- ing and is also noted as being the oldest known bridge built on a skew (with the piers not at right angles with the axis of the bridge). The amount of skew is only 13 degrees and the arch rings are built with horizontal joints. The spans are five In num- ber, from 8% to 11 meters in length, sup- ported by piers about 6! meters thick. The material used for the facing is marble and the spandrels are decorated with niches, flanked by pilasters carrying an entablature and pediment. Dentils are also used under the overhanging parapet or coping course. The architectural embellishment is unusual for a Roman bridge, most of them being ex- tremely plain and entirely devoid of applied ornament. This structure was built by the Emperor Augustus in 14 A. D., and is known as the Ponte di Augusto. (Plate xIv.) The Pont du Gard, Nimes The Romans required large quantities of water for use in their baths and amphitheatres and as they did not possess the necessary materials to build pipes to resist large inter- nal pressures, they could not use the siphon principle upon which modern engineers rely, and were, therefore, compelled to build numer- ous huge aqueducts to bring the water to them by gravity. There are many remains of these aqueducts at Rome and in the provinces. One of the best preserved examples is the aqueduct at Nimes in France, attributed to the Emperor Agrippa and to the year 14. A.D., although this is uncertain. The total length of the conduit is 40 kilometers, the aqueduct bridge itself being about 262 meters long and 51.7 meters high. The design consists of three tiers of arches, the effect of mass being augmented by the projection of numerous stones from the faces of piers and spandrels. These projecting stones were used for the support of scaffolding dur- ing construction. “The stone of this bridge is a yellowish [ 35 | BRIDGE ARCHITECTURE color. Seen under the sun from the west side, the bridge has a brightish yellow tint, with patches of dark color, due to the weather. The stone in the highest tier is a concretion of shells and sand, and that in the lower tiers appears to be the same. The stones of the two lower layers are without cement; but the arches of the upper tier, which are built with much smaller stones, are cemented.” (Sir William Smith.) The conduit itself is of con- crete, 1.30 meters wide and 1.60 meters high (Sparrow) and the thickness of the bed is 22 centimeters. The arches of the lower tier have spans of 26.4 meters each. A roadway has been added to the structure at the level of the first tier of arches. This is a modern addition. (Plate xv.) ‘“_.. It bridges the streams and it strides oer the plain; TOWER AT CENTER OF ALCANTARA BRIDGE In its arm is the river it sets down again For the fevered metropolis’ dower.” (Song of the Roman Arch—Durward.) There exist throughout France many fine examples of Roman Bridges. Worthy of espe- cial note is the bridge at Sommieres, consist- ing of seventeen semi-circular arches, and still in use, and a small but exquisite structure near St. Chamas, known as the Pont Flavien, comprising elaborate arched memorial portals at each end. The name is taken from an in- scription on the arch portals which records that one Donnius Flavius, a priest from the temple of Rome and Augustus, ordered its erection in his will. (Plate XVI.) Bridge at Alcantara, Spain, over the Tagus, on the Via Lata (Puente Trajan a’ Alcantara) This bridge is one of the most famous as well as one of the best preserved of Roman Bridges and is attributed to the Emperor Trajan, himself a native of Spain, at approximately 98 A. D. The central span is 30 meters long and the height above the river is about 30 meters. There are six spans in all, making a length of bridge of 188 meters, and carrying a roadway 8 meters wide, an unusual width for a Roman Bridge. The architect was Caius Julius Lacer, whose name is contained in an inscription on the bridge, and the funds were raised in the Roman province of Lusitania, in which the bridge was located. | This noble monument to Roman enter- prise and skill was partly destroyed in the thirteenth century and restored in the fif- [ 36 | ee SS eee ee BRIDGE ARCHITECTURE teenth, and again partly destroyed in the early part of the nineteenth century and fully restored about 1860. Al Kan’tara means in Arabian “The Bridge.” (Plate XVII.) Roman Aqueduct at Segovia, Spain This is one of the best preserved, as well as one of the noblest, of Roman Aqueducts. It also was built by the Emperor Trajan, about the same time as the bridge at Alcantara, 98 A. D., and is also constructed of granite blocks, laid without mortar. This structure is built with offsets at the tops of the several tiers, obtaining the effect of battered walls, by decreasing the thickness of the several stages—a detail of design essentially Roman. There are 119 arches, in two tiers, and the length is 876 meters for the arch structure, flanked by a solid wall 880 meters long. This structure is known locally as the Devil’s Bridge, one of the many so-called, and the name is connected with a legend, which is charmingly told in “Castilian Days” by John Hay. ““The Evil One was in love with a pretty girl of the upper town and full of protesta- tions of love. The fair Segovian listened to him one evening, when her plump arms ached with the work of bringing water from the Ravina, and promised eyes to favor if his Infernal Majesty would build an aqueduct to her door before morning. He worked all night, like the devil, and the maiden, opening her black eyes at sunrise, saw him putting the last stone in the last arch, as the first ray of the sun lighted on his shining tail. The Church, we think very unfairly, decided that he had failed, and released the coquettish contractor from her promise, and it is said that the devil has never trusted a Segovian out of his sight since.’ Study of the detail photographs of this structure, taken by Louis La Beaume, show plainly the Roman methods of construction. All stones have at least one exposed face and the bonds are quite regular, with an occasion- al header extending clear across the arch soffit, which is quite narrow. (Plates XVII, BG LO) Roman Engineering The bridges built by the Romans were merely links in a great, comprehensive system of highly improved highways connecting all parts of the great Roman Empire with the Eternal City. The expression “All roads lead to Rome” was a verity. It has been said that a resident of Britain in Roman times—and the Romans lived in Britain for nearly four hundred years—could drive to London, embark there for the main- land, and after crossing the channel could drive to Rome over highly improved and paved roads without fording a single stream. The roads were one of the great outstanding achievements of the Roman genius. Their art they borrowed, or rather commandeered, from the Greeks, but their engineering was the expression of their own spirit. Roman engineering skill was not confined to the construction of roads and _ bridges, however, but included magnificent buildings, great baths and the aqueducts and sewers to serve them, amphitheaters that have never been excelled, and, of course, military de- fences of all kinds. Only a few of the vast number of Roman [ 37 | BRIDGE bridges have survived the ravages of time, of war and of flood; most have perished, but those few are marvels of engineering skill. The Romans, however, did not, as a rule, exercise as much care in the construction of foundations for their structures as they did for the superstructures. A common method of founding in water was to divert the stream temporarily, or build open cofferdams to ex- clude the water, and when this was not prac- ticable, loose stones were often thrown into the water until a platform was obtained, of ARCHITECTURE sufficient size to serve as a foundation for the coursed masonry. The Romans understood and practised pile- driving, an art very much more ancient than Roman History, and they are known to have used timber centering for their arches, quite similar to that used today. The labor employed in the construction of these great Roman bridges was doubtless mostly slave labor, and the workmen used tools and machines of the simplest sort, the wedge, the lever, the windlass. BRIDGE ARCHITECTU eh. yi PLATE IX—ROME—PONTE ROTTO—ROMAN PERIOD FROM AN ETCHING BY ROSSINI. 1822 BRIDGE ARCHITECTURE VIHdTaGVTIHd ‘SOIGALS AVY WOUd OLOHA AYOLNAOD HINAALAT NI GHYOLSHY “NVWOU ATLYVd ‘OLSIS ALNOd—aANWOYU—X ALVId Ly pany [ 40 ] BRIDGE ARCHITECTURE NOSYHGNV AW OLOHd SNOLLVYOLSHY YALVT GNV ‘0'd 29—IdVD OWULLVAO ALNOd—ANWOU—IX ALVId BRIDGE ARCHITECTURE a ato AYOLINAOD HINGHLNAAAS - Rina ~ ¥ * Ries, oo 3 ‘OO ONIHSITHNd LIOULAG AHL NWOWd OLOHd NI Gaddv SLUdVuVd—dV Pl ‘NVIUNGVH—OTHONY °S ALNOd—AWOU—-IIX ALWTd BRIDGE ARCHITECTURE INOUd “GH AM OLOHd SNOLLVHOLSHY GNV ‘Dd 601 ‘GOIWMHd NVNOY—HATION ALNOd—AWOY—HITX ALVId BRIDGE ARCHITECTURE 190ud “da WOUd OLOHd FL “AV ‘NVIWOY—OLSNDAV Id ALNOd—ATV.LI ‘ININIH—AIX ALV Td cre BRIDGE ARCHITECTURE PL GV ‘VddIHDV YOURdNA AHL OL GALAGIULLY—duv) 1d LNOd—aAONVYA ‘SHININ—AX HLVI1d BRIDGE ARCHITECTURE Elevation dun des Arcs pilericurement.a& coupe da Pont Fan AP Os OE OE ah et EN i DONNIVS :C-E- FLAVO S:‘FLAMEN’ ROME “ot ae! oe AT TE: AVFEL SOS ‘ Sh Ae RRR 1 fee 3 3 : § 3 S 3. q desnus ere ations, plan, et coupes des Arc Fichelle des eléy Impoite ot archwolte de tAre waa Sud-eut des quatre, detuls PLATE XVI—ST. CHAMAS, FRANCE—ROMAN MEMORIAL BRIDGE FROM AN OLD ENGRAVING BY J. B. GUIBERT os ee ee ee eee ee BRIDGE ARCHITECTURE GMavwW ‘INGUAVT “f Ad@ OLOHd ‘AV 86 LOOGV “LOULIHDYV “YAOVT SAITOAL SATVO—ONVNOY ALNANd TH—NIVdS ‘VHV.INVOTVY—IIAX ALVId BRIDGE ARCHITECTURE ee A y = eae iek " sy: 1h sal oan nae sgh" ok ae : (Sat compet IY oe! 9% ant a Pe sada ry SSE > ¥ ie ati Pa yr Date ak a a pica Pee) f } q ' T—BUILT ABOUT 98 A.D. =| A PLATE XVIII—SEGOVIA, SPAIN—ROMAN AQUEDUC COPYRIGHT BY PUBLISHERS PHOTO SERVICE, NEW YORK BRIDGE ARCHITECGLURE ‘av 86 LOOdGV LIWNG HWOAVAE WT SINOT Ad OLOHd —LONGanoOV NVIWOY AO TIVLA », Ty d—NIVdS ‘VIAODAS—XIX ALVId 49 BRIDGE ARCHITECTURE PLATE XX—SEGOVIA, SPAIN—ROMAN AQUEDUCT—BUILT ABOUT 98 A.D. IW. THE MIDDLE AGES Pont St. Benezel, Avignon After the fall of the Roman Empire no bridges of importance were built in Europe until about the twelfth century, at which period some of the most notable medieval structures were erected. One of the most famous of these, as well as one of the first and the largest, is the old bridge at Avignon, built in 1177-1178 by St. Benezet, containing twenty-two ma- sonry arches, of which but four remain. The second pier supports a chapel in which repose his ashes. The design is rather crude, consist- ing of arch rings of uniform thickness, with solid spandrels, pierced only over the piers and carrying no ornamentation outside of the chapel, but the bridge was a noble work for those days, being about 900 meters in total length. Excepting as to length, this struc- ture is far inferior to the Roman Bridges. (Plate XXI.) Nearly all of the bridges of this period were built by the priests, and especially by the Benedictine Monks, who were known as ““The Brothers of the Bridge.” This order of the “Brothers of the Bridge’ (Fratres Pontifices) was formed in the twelfth century for the purpose of maintaining hospices at bridges and important ferries or river crossings. It was recognized by Pope Clement III in 1189, and became a powerful order, building and maintaining many bridges. In fact, this priest- ly order represented about all the bridge building knowledge and skill that existed in Europe during several hundred _ years. Traveling was dangerous during those cen- turies, the roads and especially the river fords being beset with robbers. The protec- tion of travelers became one of the duties of the religious orders, and the river crossings became the sites of shelters or hospices for travelers. The work of replacing the dan- gerous fords and ferries with bridges naturally followed. What witnesses of historical events these old bridges have been! Most of them have been the scenes of desperate battles, and many have suffered more from human combat than from nature. From their parapets men with- out number have been thrown to the streams below, sometimes for no greater offense than that their religious views differed from those of their captors. Most important bridges were fortified, and some, like that at Avignon, had roadways purposely narrowed at certain points so that two vehicles could not pass at those places, thus making their defense easier. And, indeed, in those rough, troubled times there was reason for such precautions. Some of these old bridges retain, by name or legend, the records of these ancient battles and massacres, such as the window in the guard room of the old bridge at Orthez (con- structed in the fourteenth century), which is still called “the Priests’ Window” because the Protestant soldiers under Montgomery who took the town by assault in 1569 are said to [ 51 | BRIDGE ARCHITECTURE have forced the priests and monks to Jump into the river from this window. One of the best examples of medieval art in fortified bridge construction is the Valentre’ Bridge over the River Lot at Cahors, France, built in the early part of the fourteenth cen- tury and comprising six arches of equal span, with solid spandrels, recessed arch rings, and pointed cutwaters carried to the full height of the spandrel walls and supporting castel- lated parapets and three high and graceful towers. In these towers every defensive device used in the warfare of those days was pro- vided, including slots for the crossbow-men and convenient ledges for the hurlers of mis- siles and pourers of burning oil. It is truly a beautiful structure as well as a fine example of a medieval fortified bridge. Considerable restoration of this structure was found necessary in the early nineteenth cen- tury. (Plate XXII.) Other interesting French bridges of the Middle Ages are found at St. Generoux where there is a thirteenth century bridge over the Thouet, consisting of five arch spans; at Airvault, the site of a structure of eleven fine arches dating from the twelfth century; at Orthez, where stands a bridge, the chief feature of which is a graceful center defensive tower built in the thirteenth century, and at Mon- tauban on the Tarn where there is a fine brick bridge constructed in the fourteenth century, known as the Pont des Consuls and possessing a delightfully mellow color im- parted to it by the old brick of which it is composed. Funds to construct the bridge at Montau- ban were raised by a tax on visitors to the [15 J town. (Plate XXIII.) All of these bridges are well illustrated in “Old Bridges of France,” by Emerson & Gro- mort. While these structures were being built in Europe, there were a number of large bridges constructed in Persia, notably at Ispahan. One of these, known as the Allah Verdi Kahn, over the Zayendeh Rud, is 350 meters long and carries a 9.1 meter roadway. Another, the Pul-i-Khajn, is 137 meters long and has a 7.3 meter roadway. Both belong to the reign of the Shah Abbas II, and to the seventeenth century. The most important and famous structure belonging to this period was the old London Bridge, replaced by the existing structure in 1831, for many centuries of English history the only bridge across the Thames at London. A bridge has been maintained at this site since the days of King Ethelred, and it is recorded that one was destroyed in 994 in a war between the Londoners and Danes. When Canute invaded England in 1015 he found this structure in his way and dug a canal around its south end in order to complete his blockade of the city, which he was unable to capture. The bridge was destroyed again in 1091 and rebuilt by William Rufus in 1097. The latter structure was in turn destroyed by fire fifty years later. It was found so costly to maintain this timber bridge that it was de- termined to build one of stone, and work was begun by one Peter, the chaplain of St. Mary’s Colechurch, in the year 1176. This ancient structure was founded upon piles supporting a grillage of plank on which the masonry was laid. According to the records, “not less than — a ee BRIDGE ARCHITECTURE 33 years were occupied in the erection of this important structure. It was begun in the reign of Henry II, carried on through that of Richard I, and finished in the eleventh year of King John, 1209. Before then, however, the aged priest, its architect, died and was buried in the crypt of the chapel which had by that time been erected over the center pier. At his death, another priest, a Frenchman called Isembert, who had displayed much skill in constructing the bridges at Saintes and Ro- chelle, was recommended by the King as Peter’s successor. But this appointment was not confirmed by the Mayor and the citizens of London who deputed three of their own body to superintend the completion of the work, the chief difficulties connected with which had indeed already been surmounted. “That it possessed the elements of stability and strength was sufficiently proved by the fact that upon it the traffic of London was safely borne across the river for more than six hundred years. But it was an unsightly mass of masonry, so far as the bridge was concerned, although the overhanging build- ings extending along both sides of the road- way, the chapel on the center pier, and the adjoining drawbridge, served to give it an exceeding picturesque appearance. “The piers of the bridge were so close, and the arches so low, that at high water they resembled a long series of culverts hardly deserving the name of arches. The piers were of various dimensions, in some cases almost as thick as the spans of the arches which they supported were wide. “This great obstruction of the stream had the effect of producing a series of cataracts at the rise and fall of each tide, so what was called “The roar of the bridge’ was heard a long way off. “The feat of ‘shooting the bridge’ was in those days attended with considerable danger, and explains the old proverb that “London Bridge was made for wise men to go over and fools to go under.’ “At the ends of the bridge were the gate houses, on the south one of which (until a comparative recent period) the grim heads of traitors and unfortunate partizans were stuck upon poles. “The bridge had a long history and many vicissitudes. It had scarcely been completed ere the timber houses upon it were consumed by a great fire, but they were shortly after erected in even more cumbrous form than before. At a very early period, the bridge showed signs of weakness and required con- stant patching. In 1281 five arches with the buildings over them were carried away in a flood. At a subsequent period Stone’s Gate, tower and arches at the southward side also fell into the river. Generation after generation of toiling men and women passed over the bridge, wearing its tracks deep with their feet, and sometimes moistening them with their tears. Still the old bridge stood on, almost down to our own day; until at last the old structure, which had served its pur- pose so long, was condemned and taken down, and the magnificent new London Bridge erected in its stead.”’ (Samuel Smiles.) It is said that the constant repairs required to maintain this bridge became so notorious that they were immortalized by being incor- porated into folk lore and even now our [53 | BRIDGE ARCHITECTURE children play to the tune of the old ditty “London Bridge is falling down.” (Plate XXIV.) It is also said in English folk lore, that ‘London Bridge is founded upon wool sacks, ” derived from the fact that its construction was partly financed through a tax on wool. In time, this statement became popularly accepted as a constructional fact. San Martin and Alcantara Bridges, Toledo, Spain For the best illustrations of the work of the succeeding century, the thirteenth, it is neces- sary to go to Spain, to Toledo, where two fine old bridges are to be found, both of them built, or rebuilt, by the Spaniards soon after the reconquest of the city from the Moors, and probably on the foundations of older Roman structures, but both decidedly Moor- ish in character, due perhaps to the fact that the Moors continued to be the skilled artisans of Spain for centuries after the reconquest by the Christians. Both of these bridges are often attributed to the Roman Period. They are named the Puente de San Martin, built in 1212 and rebuilt in 1390, and the Puente de Alcantara, originally a Roman Bridge, repaired by the Visigoths and finally rebuilt by Halaf, son of Mahomet Alameiri’ in 871, and restored in 1258 by a certain D. Alfonso, after a severe flood had destroyed most of it, as recorded upon a marble slab still in place above the point of the arch. Further repairs were made to the Alcantara in 1380 and again to the towers in 1484. Re- garding the restoration of the San Martin in 1390, the following story of human interest is told by George Edmund Street. (Gothic Architecture in Spain, 1865.) “The Architect perceived that his new arch would fall down as soon as the centering was removed. Panic stricken, he went home and consulted his wife. What could she do to save her husband’s reputation? She set fire to the scaffolding and destroyed the arch. The next time the Architect was wiser and did his work better. However, the lady could not keep her secret, and it is related that the Archbishop Tenorio, upon hearing of her action, did not punish her or her husband, but only congrat- ulated the Architect upon the possession of such a faithful wife.” Both of these bridges at Toledo are fortified with massive towers at each end. San Martin has five arches, the main arch having a span of 42.7 meters. The height above the river Tagus is about 29 meters. The arches are slightly pointed and have a projecting extra- dosal course. One of the gateways is distinct- ly Moorish. The Alcantara has only two spans and is of somewhat more massive and more rude design. It is popularly called the Roman Bridge. (Plates XXV, XXVI, XXVIJ, XXVIII & XXIX.) It will be noted from the photographs of these as well as of other Middle Age bridges, that the cutwaters or ends of the piers, and sometimes both, were often carried up to the roadway level to form recesses or additional roadway. These recesses served for traffic to pass at these places, the rest of the roadway seldom being of sufficient width to permit the passing of vehicles. They also provided con- venient places for people to congregate and [ 54 | ee BRIDGE ARCHITECTURE visit while enjoying the view, a pleasant cus- tom that still survives on new as well as on old bridges. An old French folk song runs thus: ‘Sur le pont d’Avignon, L’on y danse, l’on y danse; Sur le pont d’Avignon, L’on y danse tout en rond,”’ etc. Bridges were always popular for use as dance floors, even in Roman times. “Devil's Bridges’ and Medieval Bridge Folk Lore Throughout Europe there are many so-called “Devil’s Bridges,’ and the various folk stories connected with these bear a curious resem- blance. Usually these bridges were supposed to have been built over night by the devil, and his satanic majesty, in return for his work, had demanded the first life that passed over. Sometimes the story simply records the sacrifice of a life in the construction of the bridge. Such traditions also exist in Turkey, as shown by the following legend recorded by Sir Mark Sykes in “Dar Ul Islam.” “Many years ago workmen under their masters were set to build the bridge; three times the bridge fell, and the workmen said ‘The Bridge needs a life,’ and the master saw a beautiful girl accompanied by a bitch and her puppies and he said, “We will give the first life that comes by,’ but the dog and her puppies held back, so the girl was built alive into the bridge and only her hand with a gold bracelet upon it was left outside.” A similar belief exists in Northern Africa among the Moors to the effect that the old bridges contain a human body built into the masonry and that such a human sacrifice was necessary to the stability of the structure. Is it not credible that these legends have their origin in the circumstance that most large bridges as well as other human-built structures, have always demanded a sacrifice of human life through accident or misfortune, if not through strife or barbaric sacrifice? ‘Go! stand by Karnak’s sculptured halls; Count o’er in those cyclopean walls The record of her sacrifice One life for every stone!’’—(The Building of a Church-Durward.) Even today such legends are being started. Quite recently the author stood under the shadow of one of our new great railway bridges, over a wide American river, chatting with a native fisherman, and was quite grave- ly informed that four men were buried alive in its concrete piers, the exact location of each immuration being pointed out. Most of these old, so-called ‘‘Devil’s Bridges” are narrow, many of them without parapets and some with very steep approaches, ofttimes so steep as to merit the term “‘ladder bridges, ” sometimes applied to them. Possibly the inconvenient features of the design of such structures have something to do with the popular notion that the devil was in some way responsible for their existence. One of the best known of these bridges is the Devil’s Bridge over the Serchio at Lucca, Italy, built about the year 1000, comprising a main span of 36.8 meters and four flanking [55 | BRIDGE: ARCHITECTURE spans. This bridge has a roadway only 2.94 meters wide and its width over all is but 3.93 meters. The grades are too steep for vehicles, as, like most of the bridges of its type and time, it was intended for foot travel, donkeys and small carts. The material used is blue limestone and sandstone; the arch rings are well dressed, but the spandrels are of rubble only. Weale ascribes its long life to the fact that it was founded on rock and built with unusually good mortar. Other notable examples of this type are the bridge over the River Minho at Orense, Spain; that over the Nervia at Dolceacqua, Italy, and the Bridge of Martorelli near Barcelona, Spain. The latter has a main arch span of 41 meters with a rise of 17.3 meters. It is believed that this bridge was originally built by the Romans, and restored by the Moors about 1290 A. D. The Puente Major at Orense over the Minho is 400 meters long, belongs to the thirteenth century and is still in daily use. The large arch has a clear span of 48.5 meters and a height of 41 meters. This structure is credited to the Bishop Lorenzo. (Plates xxx, XxxI & XXXII.) Trezzo Arch During the fourteenth century, there was con- structed at Trezzo, in Italy, the longest span masonry arch ever attempted until modern times. This structure consisted of a single arch of 82/2 meters span (Hann & Hosking) across the river Adda, with a rise of 22.3 meters, about the dimensions of the recently constructed Walnut Lane concrete arch in Philadelphia. It was completed in 1377 and served until destroyed during a war in the year 1416. Its arch was segmental in form and constructed of granite. It was never rebuilt. The Ponte Vecchio over the Arno—Florence This is one of the few remaining “‘Industrial Bridges,” as bridges containing shops along the sides of the roadway are sometimes called. The old London Bridge was a notable example of this type, and many of the older Paris . bridges had shops and dwellings constructed on their sides. The Ponte Vecchio belongs to the early fourteenth century and consists of three segmental arches of 27.8 to 31.4 meters span and 34.3 meters width and supports a covered gallery connecting the Pitti and the Ufizzi Palaces. This work is attributed to the architect Taddeo Gaddi, best known for his paintings and mosaics. (Plate XXXIII.) The Charles Bridge at Prague The Karlsbriicke over the Moldau at Prague was begun in 1357 by the Emperor Charles V and finally completed in 1503. It probably still holds the world’s record for length of time under construction, 146 years. It is 607 meters in length, made up of 16 arches, the longest of which has a span of 22.7 meters. At one end of this bridge is a lofty and inter- esting medieval tower, while the parapet is ornamented with figures of the saints, one of which, near the center, is a statue of St. John Nepomuk, the patron saint of Bohemia, who, tradition says, was thrown off the bridge and drowned at the command of the King, to whom he refused to reveal the secrets of the confessional. (Plates XXXIV & XXXV.) [ 56 | ee a ee ee a Sa ee ————— ee ae ee ee ee ee, ee BRIDGE ARCHITECTURE At Pavia, Italy, there is a remarkable covered bridge over the Ticino, dating from 1351- 1354, and consisting of seven pointed arches of brick, the arches having spans of about 21.4 meters anda height of about 191% meters. The architect was the Governor, Gian Gal- eazzo Visconti, who also founded the Univer- sity of Milan and was responsible for much other contemporary (Plate XXXVI.) architectural work. Verona and Zaragossa The fifteenth century is almost devoid of any notable achievement in bridge construction, two of the few products of that century worthy of note being the bridge at Verona, Italy, known as the Ponte Della Pietra, and the Puente de Piedra over the Ebro at Zaragossa. (Plates XXXVI, XXXVIII, & XXXIX.) The former is partly Roman, restored in the fifteenth century, the restored parts easily recognized by their widely different character. The latter dates from 1437 and consists of seven arch spans, segmental, plain and mas- Sive, with very heavy piers of unequal width, some of them almost as wide as the arch span. The Ponte Della Pietra at Verona is much more refined in design, consisting of five arches, segmental, of variable span and car- ried upon piers, no two of which are alike in dimensions or detail. The spandrels over two of these piers are pierced by openings, one of which is a large circular opening, the most distinctive feature of the structure. A fine illustration of the Medieval spirit in bridge design is the Castelvecchio of Verona with its battlemented railing. (Plate XL.) This picturesque bridge was completed in the year 1356. The architects were probably Jean de Ferraro and Jacques de Gozzo. The arches are 24 meters to 48.7 meters span, and the roadway width 5.5 to 6.8 meters. We are now reaching the end of the medieval period in bridge construction, characterized mostly by rude, massive, brutal strength, but also boasting many structures of bold design, more bold in conception than the preceding Roman work, but much more crude in work- manship, and we are approaching the more refined and skilled period of the Renaissance and modern times. We leave these ancient structures with some regret and are reminded of the dialogue be- tween the ““Brigs of Ayr’ as related by the poet Burns, who puts into the mouth of the Auld Brig Sprite the prophecy that the newer one will succumb first to “flood and spate,” a prophecy that eventually came true. The Auld Brig is said to date from the reign of Alexander III, who died in 1286, and it therefore belongs to about the middle of the thirteenth century. The new Brig was built in 1788 and was destroyed by a flood in 1877 and had to be rebuilt. Where can we find finer contempt of the new for the old or a better description of a river in flood than here? (Plate XL.) NEW BRIG Auld Vandal, ye but show your little mense, Just much about it wi’ your scanty sense; Will your poor, narrow foot-path of a street, Where twa wheelbarrows tremble when they meet, Your ruined, formless bulk of stone and lime, Compare wi’ bonny Brigs 0’ modern time? There’s men of taste wou’d tak the Ducat-Stream, Tho’ they should cast the vera sark and swim, Kre they would grate their feelings wi’ the view O’ sic an ugly, Gothic hulk as you. [ 57 | BRIDGE ARCHITECTURE AULD BRIG Conceited gowk! puffed up wi’ windy pride! This mony a year I’ve stood the flood an’ tide; And tho’ wi’ crazy eild I’m sair forfairn, I'll be a Brig when ye’re a shapeless cairn! As yet ye little ken about the matter, But twa-three winters will inform ye better. When heavy, dark, continued, a’-day rains, Wi’ deepening deluges o’er-flow the plains; When from the hills where springs the brawling Coil, Or stately Lugar’s mossy fountains boil, Or where the Greenock winds his moorland course Or haunted Garpal draws his feeble source, Arous’d by blust’ring winds an’ spotting thowes; In many a torrent down his snaw-broo rowes; While crashing ice, borne on the roaring spate, Sweeps dams, an’ mills, an’ Brigs, a’ to the gate; And from Glenbuck, down to the Ratton-key, Auld Ayr is just one lengthened, trembling sea; Then down ye'll hurl, deil nor ye never rise And dash the gumlie jaups up to the pouring skies. A lesson sadly teaching, to your cost, That Architecture’s noble art is lost! Note: Ducat-stream—a ford; mense—good manners; eild— age; cairn—wreck; rowes—rolls; the gate—road or way; Ratton-key—‘‘Rat-hole’’—a landing place at the river’s mouth. Another Scottish Bridge, although of a somewhat later date and also famed in song, is the “Auld Brig of Doon.” (Plate XL.) At Biddeford, England, an old bridge of uncertain age, but probably belonging to the fourteenth century, is of peculiar interest in that it presents the unusual spectacle of the use of the arch and beam principles combined in a single structure and material. The road- way is carried on masonry arches and the walks on stone lintels. (Plate xii.) This bridge formerly supported a chapel from which indulgences were sold by Grandison, Bishop of Exeter, in order to obtain funds to complete the structure. Medieval Engineering Following the fall of the Roman Empire and the decay of Roman civilization, engi- neering skill sank to a comparatively low level, and throughout the Middle Ages con- tinued to be almost non-existent. To be sure, wonderful churches and fine palaces were built during this period in Europe, but the skill displayed in their con- struction was the skill of the craftsman and not the careful, accurate planning of the engi- neer, as exhibited in the earlier Roman struc- tures and later in the eighteenth century. The civilization of the Middle Ages, based upon the feudal system, was not conducive to the development of engineering skill. The cities were more or less independent military strongholds, having little civil intercourse with each other and consequently small need of improved highways and the bridges that form a part thereof. Other branches of engineering were also neglected, and sani- tation was almost unknown. As a result there were frequent pestilences that decimated the population. On the other hand, slavery disappeared and such structures as were erected were the work of free men, a notable characteristic of the period being the development of the craftsmen’s guilds, which gradually became powerful organizations. [ 58 | ae Se a ae eee BRIDGE ARCHITECTURE VIHdIAGVIIHd ‘SOIGALS AVY WOM OLOHd 8L11 GULAIdNOO—LAZANAd (LS LNOd—aAONVUA ‘NONDIAV—IXX ALWId BRIDGE ARCHITECTURE a Fie i ee 4 SS - —- a ee ee Sluvd ‘Sauda NIGGUNAN AM OLOHd AYOLINAD HINAALYNOA—LOT AHL YAAO “ADC AWLNATVA—HONVYA ‘SUOHVO—IIXX ULV Td [ 60 | —~ <.. oe e BRIDGE ARCHITECTURE PLATE XXIII—MONTAUBAN, FRANCE—PONT DES CONSULS OVER THE TARN—XIVTH CENTURY A MEDIEVAL BRIDGE OF BRICK PHOTO BY NEURDEIN FRERES, PARIS [61 ] BRIDGE ARCHITECTURE PLATE XXIV—LONDON—THE OLD LONDON BRIDGE—PHILIP OF COLECHURCH, ARCHITECT, 1209 FROM A DRAWING BY H. W. BREWER, IN “OLD LONDON ILLUSTRATED” BRIDGE ARCHITECTURE MYOA MON ‘GOOMYAGNA ¥ GOOMUTGNA AG OLOHd 06€L LTINGAY ‘ZIZl LHOAA—NILYVW NVS AG ALNANd—NIVdS ‘OGHTOL—AXX ALVI1d 63 | | LURE ye eh HITEC ‘ A AR( E aT I BRID¢ MYOX MAN ‘GOOMUTGND ¥F GOOMYGGND Ad OLOHd 0661 LITNGAY ‘cIél LIING—NILYVIN NVS 4d ALNANd—NIVdS ‘OGHIOL—IAXX ALVId [ 64 ] BRIDGE ARCHITECTURE PLATE XXVII—TOLEDO, SPAIN—PUENTE DE SAN MARTIN—DETAIL COPYRIGHT BY THE PUBLISHERS PHOTO SERVICE, NEW YORK E ARCHITECTURE “4 x BRIUDC HUOA MAN ‘ADIAUAS OLOHd SUSHSIIANd AGT AALHOTUAdOD OLOHd SAIMA.LINAD HLLT GNV HL&l LTIOGAY—-VYVINVOTV AC ALNANd—NIVdS ‘OGATOL—INAXX ALVITd 8 @ ie a” [ 66 | BRIDGE ARCHITECTURE HOIAWHS OLOHd SUAHSITANd WOYA OLOHdA SHTYOLNAD HINAALNAAYS GNV HLINGALYTHL NI LW ‘NVIWOU ATIVNIDIMO—HDUV NIVIN AO TIVLHAG—VYVINVOTV AG ALNANd—NIVdS ‘OGHIOL—XIXX ALV Id [ 67 | HITECTURE | | AR L BRIDGE MUOA MAN ‘AOIAUAS OLOHd SHYAHSITANd WOUdA OLOHd 0€Zl ‘OZNAHOT dOHSIA OL GALIGAYD ‘OHNIW AHL YAAO ADGA LNAIONV—NIVdS “ASNHYO—XXX WLV Id BRIDGE’ ARCHITECTURE Tees: ake PLATE XXXI—DOLCEACQUA, ITALY—“THE DEVIL’S BRIDGE”—MEDIEVAL BRIDGE OVER THE NERVIA PHOTO BY UNDERWOOD & UNDERWOOD, NEW YORK [ 69 | BRIDGE ARCHITECTURE MUOK MAN ‘AOIAUGS OLOHd SUAHSITANd Ad OLOHA 06zl LNOGV ‘SHOOW AG LTINGAY ‘NVNOY—AOGINE S.TIAAG AHLI—NIVdS ‘ITIAYOLYVIN—IIXXX FLVTd BRIDGE TARGET EC CU RE MYOA MAN SHOLAMAS OLOHd SUAMHSITANd WOU OLOHd AYOLINAD HINADALYNOA—LOALIHOYY ‘IdGV9 OAGGVL—OIHDDHA ALNOd—ATVLI ‘TONAYOTA—_UIXXX ULV Td BRIDGE ARCGHIT ROGEUEE AMONYASTYV YANO VUd—AIXXX HLVId BRIDGE ARCHITECTURE PLATE XXXV—PRAGUE—KARLSBRUCKE—THE POWDER TOWER PHOTO FROM THE DETROIT PUBLISHING CO. [73 ] BRIDGE AR@G@HITECTURE a et sitihy SONGUOTS ‘IOOUT “A AM OLOHd LOULIHOUV ‘TLNOOSIA OZZVATVD NVID YONYUAAOD—?SEI—ONIDLL TNS ALNOd—ATVLI ‘VIAVd—IAXXX BLVId [ 74 ] BRIDGE ARCHITECTURE 1IN0Ud “GH WOUd OLOHA AYQINGD HINKHLAA GNV NVINOU—VULAId WITH ALNOd—ATVLI ‘VNOUHA—TAXXX ALWId BRIDGE ARCHITECTURE ae PLATE XXXVIII—VERONA, ITALY—PONTE DELLA PIETRA—DETAIL—ROMAN AND FIFTEENTH CENTURY PHOTO FROM UNDERWOOD & UNDERWOOD, NEW YORK [ 76 | TURE “ A BRIDGE ARCHITEC L€vVI—VuUddId Ad ALNANd—NIVdS VSSODVYUVZ—XIXXX ALVTd BRIDGE ARCHITECTURE PLATE XL—VERONA, ITALY—CASTELVECCHIO, DETAIL—1356—JEAN DE FERARE & JACQUES DE GOZZO, ARCHITECTS PHOTO FROM M. PAUL SE/JOURNE’ BRIDGE ARCHITECTURE PLATE XLI—SCOTLAND—THE TWA BRIGS O’AYR—THE NEW BRIG COMPLETED 1789, DESTROYED 1878, AND REBUILT THE AULD BRIG BUILT IN THE THIRTEENTH CENTURY—RESTORED 1912 peo BRIDGE ARCHITECTURE PLATE XLII—SCOTLAND—THE AULD BRIG 0’ DOON BRIDGE ARCHITECTURE PLATE XLIII—BIDDEFORD, ENGLAND—OLD MASONRY BRIDGE—PROBABLY FOURTEENTH CENTURY PHOTO FROM WIDE WORLD PHOTOS [ 81 | IV. THE RENAISSANCE PERIOD The Renaissance, which characterized the art and architecture of the fifteenth and sixteenth centuries, seems to have had little effect upon bridge design in the fifteenth century, al- though during this period Brunellesco was building the Church of San Lorenzo and the Pitti Palace in Florence, and Alberti was con- structing the Palace Rucellai. Possibly the thought of the time did not extend to prob- lems of transportation, of which bridges are an important part. In the sixteenth century, however, the effect of the Renaissance is seen in many fine bridge structures, designed and built by some of the noted architects of the period, such as The Trinity Bridge at Florence, by B. Ammanati, the Rialto and The Bridge of Sighs at Venice, both by Antonio da Ponte, contemporary of Michael Angelo and of Palladio. Andrea Palladio was an Italian architect of the sixteenth century who designed many im- portant buildings, but who is best known as the author of a classic treatise on architecture. In this book we find the following inspiring — statement: “Bridges ought to have the self- same qualifications that we judge necessary in all other buildings, that they should be commodious, beautiful and lasting.”’ The Rialto Bridge, Venice The Ponte di Rialto, over the Grand Canal, completed in 1591, consists of a single seg- mental arch of 51.7 meters span and has a [8 width of 23.6 meters. It is a covered bridge, carrying a seven-arched arcade, the center arch of the arcade larger and higher than the others, and protected by a gabled roof. (Plate XLIV.) Bridge of Sighs The Ponte di Sospire, or Bridge of Sighs, is so named because it connects the Ducal Palace, or Court of Justice, with the jail. It is doubt- less the most photographed and most painted bridge in all the world. It is a single arch of elliptical design, carrying a covered passage- way, highly ornamented with human heads and cartouches, and surmounted by a heavy arched parapet. It is generally conceded that neither of these structures are worthy exam- ples of Renaissance Art because they are in- ferior in design to contemporary work in buildings. The Bridge of Sighs was completed in 1597. (Plate XLv.) Trinity Bridge, Florence A better designed structure, perhaps, is the Trinity Bridge at Florence, built about 1570 and consisting of three basket-handled arches with rather steep approaches and embellished with statues and carved keystones. The spans are 29.3 meters and 26.2 meters. Some author- ities have criticized the design of the piers of this bridge as being too thick in proportion to the rest of the structure. (Plate XLVI.) For a good example of renaissance archi- tecture in bridges, we must look to the | BRIDGE: ARCHITECTURE seventeenth century, a period that witnessed a distinct advance in pleasing design, al- though but little progress in the scientific principles involved. For instance, we have at Chatsworth, Eng- land, an ornamental little bridge built about 1668 and consisting of three arch spans, ex- quisitely detailed, the cutwaters of the two center piers carrying statues and the parapet consisting of an open balustrade. Certainly this little bridge is an architectural gem, if not of much importance for purposes of trans- portation. Evidently, its charm is due largely to its surroundings, as it is part of a beautiful country seat. (Plate XLVI.) At Paris, however, are three notable bridges over the Seine belonging to this period, the Pont Neuf, the Pont Royal, and the Pont Marie, all serving as important links in heav- ily traveled arteries. The Pont Neuf, Paris The Pont Neuf was begun in 1578, the first stone being laid by Henry III. It was com- pleted in 1604 and is still called the “New Bridge.” Although this bridge has since that time been largely rebuilt, the restoration is an exact one. Its length is 353 meters and the width 23.6 meters. The spans of the twelve arches vary from 14 to 17.55 meters. The arch rings are three centered, nearly elliptical, and the piers have pointed cutwaters, surmounted by circular pilasters, which are carried up to the roadway, forming circular recesses in the foot-walks. The general effect of these details is to increase the appearance of massive con- struction. This monumental structure, “the Patri- arch of Paris bridges,’ was constructed by the architects Marchand and Androuet. (Plate JEN AN 4 The Pont Royal, Paris The Pont Royal has five arches, the largest one with a span of 23/2 meters. The width is 17 meters. It was completed in 1689 by the architects M. Mansart and J. Gabriel with the assistance of one Francois Romain from Holland, who is said to have been the first to employ open caissons or boxes, for construct- ing underwater foundations. “The bridge, while of the utmost simplicity in form, and without a vestige of decoration, nevertheless holds the attention of everyone whose eyes are open to the beauty of proportion.” (Emer- son and Gromort.) The arches are elliptical in form and the cutwaters are triangular, surmounted with pyramidal caps reaching almost to the coping. There are no recesses, however, in the road- way. (Plates XLIX & L.) The Pont Marie, Paris The Pont Marie was completed in 1635 and named after its builder, M. Christophe Marie, who completed it at his own expense, receiving as compensation therefor a grant of the un- built section of the island. (Isle de Paris.) It consists of five nearly semi-circular arches of cut stone. Two arches were washed out in 1658, and except for this, the bridge has served traffic nearly 300 years without cessa- tion and with slight repairs. Its first stone was laid in 1614 by Louis xr and Marie de Medici. This bridge at one time supported houses on its sides, and it is recorded that 120 [ 83 | BRIDGE ARCHITECTURE persons were drowned when two arches were destroyed in 1658, and all of the remaining houses were torn down in 1788. The width is 23.6 meters. The bridges of Paris constitute a pleasing ensemble not equaled anywhere else in the world. This effect is due partly to the beauty of the structures themselves, but largely to the skill with which they have been made to fit into the surroundings, the approaching highways and the masonry quay walls. (Plates LI & LII.) Charles Mulford Robinson, in “‘Modern Civic Art,’ expresses this and other attributes and requirements of good bridge design so well that we take the liberty of making the following quotation from his writings: ‘In the case of a stream, bridges must form a very important feature of the water-front development, merely considered architectur- ally and scenically. The bridges that spring from the quays of Paris seem an inseparable part of the construction. It happens that they are separable, and rarely coincident in date with it; but this does not appear. The bridge that begins and ends in the quay must harmo- nize with the quay; and the quay must provide, in broadened plaza and hospitality to con- verging streets, a bridge approach that shall be at once suitable and convenient for the travel. The surface appearance of the bridge belongs to another discussion. We are here considering the town’s water approach, where only a lateral view of the bridge is offered— the one view, however, that adequately gives the structure’s architectural value; and with its art importance alone is there now concern, engineering merit is assumed. ‘Stone construction, or at least stone piers, are obviously invited strongly by the masonry of the embankment in order to secure har- mony. Beyond this, the charm of the bridge will lie mainly in long horizontal reaches. Perpendicular motives will not be necessary, and though it is quite the fashion, in the rare cases of an effort to make bridges monu- mental, to put a tower, or towers, in the centre, there is always a danger that these will have an isolated appearance. The place for the monumental treatment is at the point on the shore which is to be emphasized as the water gate; but the bridge, if designed con- scientiously as a work of art that shall be permanent, as cities go, and always very con- spicuous, may be made a thing of beauty with no such piling on of ornamentation. Of course at times the necessity for a centre draw justi- fies, and even requires, perpendicular motives; but these need not be deliberately invited to make the bridge imposing. If they are in- vited, the ideal place for them is at the struc- ture’s end. There they may easily emphasize the portal significance which all bridges have when the water which they span forms the boundary of the town. Interesting examples of this effect are offered by, for instance, the Charles Bridge at Prague (See Plates XXxIv & XXXV), and the railroad bridge at May- ence. (See Plate Gxxvut.) In fact, of the lat- ter it has been remarked that while the bridge is of the very ordinary truss type, the architects have saved it aesthetically by pro- viding ‘a handsome and imposing, not to say romantic, entrance, which not even railroad tracks can ruin.’ Further than that, it is an entrance, we may note, that has meaning. [ 84 ] BRIDGE ARCHITECTURE “There are other principles which will be useful as guides in choosing bridge designs that are likely to please. Not only should the structure harmonize, as far as possible, with the quays and with its general setting, not only should its beauty be sought mainly in long horizontal reaches,—to the distrust of perpendicular effects, using the latter at the bridge ends if at all (when this is possible), but 1t must be remembered that the beauty of the bridge as a whole depends mostly on its main lines. Any attempt to deceive as to the nature and position of these by concealing them with ornament can only fail, being false to every principle of art. To beauty of form in these main lines, there must then be added Symmetry. “Tmagine a stone bridge of several arching spans. It is not enough that the lines of these spans be lovely. There must be symmetry be- tween the spans themselves, so that, for ex- ample, on either side of the center they shall be equal in number and size—an obvious matter, and yet one often ignored. And the bridge must harmonize with its natural set- ting and its purpose as well as with its con- structed terminal. This applies to the degree of its massiveness, to the character of the scenery, or, if it be in the midst of a city, to the style of the architecture amid which it stands. “Let it be recalled that while the purpose of the bridge is utilitarian there is no other structure in the city that has greater perma- nence, or as great a prominence, for good or ill. There is nothing that should be built with more consideration for the artistic result. In- deed, is it not true that a bridge across the Thames in London is upon the same plane of monumental and architectural importance as is St. Paul’s itself, and so makes demand for the like skill and taste to design and to em- bellish it? The Romans, who were the great bridge-builders of antiquity, had no higher title to bestow than the term ‘Pontifex Max- imus —greatest builder of bridges. And to- day, in an industrial age, it may be remarked, the bridge and viaduct are to us about what the town gate was to the builders of ancient times, so that it behooves us to demand not merely strength but dignity and a civic splen- dor, in their construction. Every city bridge is an opportunity; and as to the smaller towns, how charming a memorial a beautiful bridge might be! The triumphal arch can be made effective only at great expense. It is a vain- glorious type; while in the bridge the arch is at the service of humanity. “A Greek Sculptor charged his pupil with having richly ornamented a statue because he ‘knew not how to make it beautiful.’ Beauty is dependent on a fineness of line, a chastity of form, the lack of which can be atoned for by no ornament that is superimposed, by no added decoration. ”’ Toulouse and Chatellerault, France There exists at Toulouse, France, a remark- able bridge over the river Garonne, begun in 1543 and finally completed between 1626 and 1632, the exact date being uncertain. The de- sign is attributed to Nicholas Bachelier and his son. The triumphal arch at one entrance was erected by the architect Mansart. There are seven elliptical arches, and small circular openings over all piers. It is supposed [ 85 | BRIDGE that the unfinished appearance of the vous- soirs over the spandrel openings is not inten- tional, but that the designer intended to carve a pattern thereon. All of these arches are enlarged upon the upstream side by a device known as the “‘corne de vache,” or cow- horned arch, consisting of flattening the curve at the face of the arch, thus forming a funnel- shaped opening at the arch face. This device is often met with in old French bridges. At Chatellerault, also, there is a somewhat similar structure consisting of nine arch spans over the River Vienne, completed in 1611, having been under construction forty-four years. The cornes de vache on this structure are very pronounced as is also the cornice. A beautiful entrance way at one end is a feature. This bridge is known as Le Pont des Con- suls and has an average span of 22 meters. It formerly had massive towers. ARCHITECTURE Both the Toulouse and Chatellerault Bridges are well illustrated by drawings in Emer- son and Gromort’s “Old Bridges of France.” (See Plate Liv for a good example of the use of the corne-de-vache, on the old bridge at Toulouse, France.) Engineering of the Renaissance A characteristic of the Renaissance period is the improvement in the construction of the substructures or foundations for bridges, as well as in the execution of the superstructure. This improvement consisted chiefly in the in- creasing use of wood piling and timber grill- ages, or platforms, for foundation purposes, already applied to many of the medieval structures, as, for instance, the old London Bridge, and in the better workmanship of the stone masons, evidencing an increasing skill on the part of the designers and workmen. [ 86 | BRIDGE ARCHITECTURE AONAUOTA ‘IN0Ud “GA Ad OLOHA LOALIHOYV “ALNOd Vd OINOLNVY—16SI—OLTVIY Id ALNOd—ADINGA—AITX FLV Id ARCHITECTURE BRIDGE “= “SZARSE a a )’ | ( sqvemeeeaneees il HITEC al 4 1597—ANTONIO DA PONTE, AR NAISSAN( PHOTO BY BROGI —RE == DI SOSPIR ITALY—PONTE XLV—VENICE, PLATE [ 88 | BRIDGE ARCHITECTURE AONGUOTA ‘TOOU “Gt WOW OLOHd 02ST LOOPVY—LOULIBOYV TLYNVWWY “d—VLINIML VITAd ALNOd—ATVLI ‘AONHHOTA—IATX SE SS Bec ta ALV Id ] 89 [ BRIDGE, ARCHITECTURE 8991 LQNOPVY—HAONVSSIVNAYY—HLYOMSLVHD ‘GNVTONA—IIATX FLV Id Tr Tie PRO rire [ 90 ] BRIDGE ARCHITECTURE sluvd ‘WNaASSVAGT Ad OLOHd ] af 143 m Al if i ah | oe Gl SLOALIHOUV ‘LHNOYAONV ¥ GNVHOYVN—F09l GALATdNOD—ANHN LNOd AT—SIYVd—ITATX ALV Td * Foat Cl . 3 Bank j ’ — BavoURorRaeRe t Pe Fu a H ye &. be ee as me jeg as Hg mp sh Oe BRIDGE ARCHITECTURE SLOULTHDYV “THIUAVD f£ ¥ GUVSNVA "N—6891 GALA TAWOO—SAIMATIOL SUT LA TVAOYW LNOd AT—SIYVd—XITX ALVI1d 7 =e ~ __. e Test r —— 7 oe : \ jpeaies ata ots Meath Seatehei hee ed ee te thy Rhee eh Ahad ot AAS thet fst = [ 92 ] BRIDGE ARCHITECTURE SIuVd ‘YNASSVAGT AG OLOHA 689I—SLOULIHOUV “THIYAVD ‘£f Y LYUVSNVIN ‘W—IVAOY LNOd WI—ADONVHA ‘STUVd—T ALV Id | 93 [ BRIDGE ARCHITECTURE ns rt f 1981—ATTIA Ad TALOH.T GNV SINOT “LS LNOd—SIYVd—IT ALVTd an Pe Tiere iin eee HAL i . SMC GAG bas asta cere Fe chose vey 8 #/ ee F ‘ 7 ' : pg 7 UGE sero iytt gpa 6 it eee oe a BRIDGE ARCHITECTURE SHOdIYd HAO VNVYONVd—STYVd—IIT ALV Id BRIDGE ARCHITECTURE 190ud “da WOud OLOHA 0991 LIINGAY—OZZAW Id ALNOd—ATVLI ‘VSId—HIT ALV Td : £ b 2 ? . si V. THE EIGHTEENTH CENTURY We have seen that all through the middle ages and up to the eighteenth century, all notable bridges were designed by the priests and by architects. The professional engineer had not yet appeared in the picture, at least not as differentiated from the architect. In the eighteenth century, however, the engineer appeared on the scene, and a revolution in bridge construction took place, science be- coming a principal factor in design, without displacing art at that time but by displacing only ignorance and crudity. Chief among these men were Perronet in France, and Rennie in England, the first recognized professional bridge engineers, and both belonging to the last quarter of the eighteenth and first quarter of the nineteenth centuries. Perronet was responsible, among numerous projects, for the bridge over the Seine at Neuilly, a suburb of Paris, built 1768 to 1773, and consisting of five arches, each with a span of 39 meters, and also for the Pont de la Concorde at Paris, built 1788. The famous Loire Bridge at Orleans was built by Perronet in collaboration with Hupeau, a contemporary engineer. (Brief biographies of Rennie and of Perronet may be found in Appendix C.) The Pont de la Concorde The Pont de la Concorde was the first bridge in Paris to be constructed with segmental arches. It has five spans with rises of only about one-eighth the opening—bold propor- tions for those days. It is considered to be Perronet’s masterpiece. One of its features is the use of an open balustrade, or railing, of stone posts and spindles instead of the usual solid parapet wall of its predecessors. This bridge is 15.59 meters wide between faces. The central arch has a span of 31.18 meters with a rise of 3.97 meters, the flanking arches being somewhat less. Perronet intended to use cyl- inder piers in the plan of the Pont de la Con- corde as he had already done in the design of a bridge at St. Maxena, but the approaching revolution led him to abandon this plan in favor of the straight pier in order to speed up the work. The cutwaters are about three- quarters attached circular columns, extended to the coping and supporting heavy masonry posts probably intended as bases for statuary, but never so used. There are no recesses in the foot walks. Perronet was the first director of the Ecole des Ponts, founded by Turdaine in 1747, the first school of bridges. Perronet used the device known as the “‘corne-de-vache”’ (cow-horns) extensively and said of it: ““This arrangement facilitates the introducing of the water and gives more lightness and boldness of effect to the bridge.”’ The use of the flat segmental arch was another characteristic of his work. (Plate Lv.) Rennie is best known as the engineer for the New London Bridge, built in 1831, the Waterloo Bridge at London built in 1817, and the old Southwark Bridge of cast iron [ 97 | BRIDGE ARCHITECTURE arches, built in 1819. Rennie, however, built many other creditable structures in England and Scotland. A characteristic of his bridges is the use of the elliptical arch, in order to obtain a low, level roadway, while Perronet evidently preferred to use the flat segmental arch to obtain this same result. It will hardly be questioned that the semi- ellipse curve gives the more pleasing results, due largely to the fact that it presents to the eye a completed curve, whereas the segmental form is but part of a curve, it is incomplete. This likewise holds true for the semi-circle, which also gives the effect of a completed curve. Similarly, the simple mathematical curve has a charm not possessed by curves made up of a combination of different mathe- matical curves, such as we see in the three- centered and five-centered types, and in curves of varying radii, such as are commonly used today in the design of reinforced concrete bridges. When it-is necessary to use the seg- mental type of arch, as it often is, the designer should recognize the apparent necessity for skewbacks or abutments sufficiently massive to provide for the evident thrust, to the eye, of the uncompleted arch. In general, it may be stated as a cardinal principle of design that simple and complete curves are preferable for arch rings. These pioneer bridgeengineers, Perronet and Rennie, built structures that were much more beautiful, as well as more practicable, than any of their predecessors, in any age, whether ar- chitect or priest, Roman or Medieval. Pos- sibly this is due to the fact that engineering and architecture were still closely related, and these engineers were students of both. The Waterloo Bridge The Waterloo Bridge, designed by Rennie, consists of nine arch spans of elliptical shape, each span having a length of 120 feet and a rise of 34 feet. This bridge, originally called the ‘Strand Bridge,’ was re-named the Water- loo Bridge in honor of the battle of that name. The design, while universally admired for its beauty, has been the object of some criticism because of the use of columns at the piers, which are obviously superfluous ornamentation. Thomas Pope, writing in “A Treatise on Bridge Architecture,” thus pays his respects to this detail, perhaps somewhat unjustly, but not without point: “Dear little columns, what is’t ye do there? We know not, sir, unless to make you stare.” Apropos of the same problem, William Hosking wrote nearly a century ago, ““The usual materia architectoricae are entirely out of place, and out of character, in bridge com- positions. Columns and approximation to columnar form and proportion, pilasters, en- tablatures, niches, battlements, balustrades, towers and turrets, pinnacles and pediments, are gauds and devices, in the application of which to bridge composition the most emi- nent engineer-architects have failed to pro- duce anything but meanness or absurdity, or a combination of both. “Ifa work such as a bridge be well composed constructively, whatever may be the constit- uent material or materials employed, and whatever may be the kind of construction, it can hardly fail to be an agreeable object for it will certainly possess the essentials to beauty [ 98 | BRIDGE ARCHITECTURE in architectural composition, simplicity and harmony. The introduction of anything not necessary to the construction, the omission of what is requisite, or the substitution of a bad expedient for a good one, will assuredly tell injuriously upon the eye, how incompetent soever the observer may be to determine the cause of the defect, or even in what the defect may consist. It is impossible, therefore, to draw any line between the constructive and the decorative, or what is commonly termed the architectural composition of a bridge.” (Plate LVI.) The New London Bridge The New London Bridge comprises five ma- sonry arches, of elliptical shape, and is 926 feet long. The roadway, originally but 35 feet wide, was widened in 1905 to 65 feet and again in 1915 by the insertion of massive gran- ite corbels to a width of 76 feet. This last widening was carried out by Andrew Murray, architect, and G. F. W. Cruttwell, engineer. This bridge was and still is a masterpiece of simple, yet effective design, entirely devoid of the ornamentation for which the earlier Waterloo bridge has been criticized. The piers have circular cutwaters, slightly pointed, and the spandrels are built with coursed ashlar jointed precisely to the voussoirs of the arch rings, the entire effect being one of carefully executed design and workmanship. Recesses are provided over all piers. (Plate LVII.) These London bridges have served the heav- iest traffic for over a century and only lately have they shown signs of serious distress, due chiefly to deterioration of the timber grillages or platforms supported by piling upon which the piers are founded. The same weakness is causing concern for the safety of Sir Christofer Wren’s masterpiece, St. Paul’s Cathedral. Immediately after the great London fire this eminent architect, engineer and mathe- matician, collaborator with Sir Isaac Newton in the writing of ‘‘Principice,’’ planned, among other improvements, to rebuild the old Lon- don Bridge, a plan that was not carried out at that time. A picturesque bridge of the eighteenth cen- tury is the “Old Bridge” at Heidelberg, Ger- many, built 1786 to 1788 by the Elector Charles Theodore, whose statue, in company with one of the goddess Minerva, adorns the parapets. (Plate LVI.) At Chalon, France, there is a bridge of very unusual design, over the River Saone, known as the Pont St. Laurent, completed in 1782 by Emilian Marie Gauthey, a noted French engineer and author of a book on bridge con- struction. The plan is unsymmetrical, com- prising four semi-circular arches and one seg- mental. The structure is ornamented with carvings in the spandrel recesses, and the arch rings are double and strongly marked, but the most remarkable detail is the exten- sion of the triangular breakwaters to a point well above the roadway level. Another fine bridge by Gauthey is that over the Saone at Chalon, known as the Pont des Echavannes. (See “Old Bridges of France” for many fine drawings of Gauthey’s work.) Among smaller structures built in this period, one of the most famous is the Pont- Y-Pridd, in Wales, completed by a William Edwards in 1750 after two attempts had failed. This belongs to the “Devil’s Bridge” 22] BRIDGE type, having steep grades and narrow road- way. A peculiar feature is the provision of the openings in the spandrels. The span is 140 feet. It is said that Edwards’ father was drowned at this point and that the building of the bridge was in fulfillment of a vow made by the son at that time. The more modern low grade bridge alongside this old structure affords a marked contrast between the old and the new. (Plate LIX.) Before leaving the eighteenth century we should not forget to mention the masonry arch bridges built by Smeaton at Perth, at Banff, and at Coldstream in Scotland, all quite similar in design to Rennie’s work and belonging to the latter part of the eighteenth century. An important factor in the construction of all masonry bridges in all times has been the quality of the cementing or jointing material used. As we have already noted, much of the old Roman work was laid up without mortar joints, dependence being placed upon careful dressing of the abutting beds of the stones, at which their workmen were very expert. The Romans, however, knew how to manufacture an excellent cement which they used freely in mortar and in concrete for much of their bridge construction. The art of making this - cement was lost for a thousand years during the middle or dark ages. Smeaton, the engineer in charge of the de- sign and construction of the Eddystone Light- house, quite a famous engineering feat in its day, conducted some studies and experiments in connection therewith which led to his re- ARCHITECTURE discovery of so-called Natural Cement in 1756. In 1824, another English engineer, Joseph Aspdin, made the first Portland Cement, dis- tinguished from the natural kind by being made from a mixture of raw materials, a dis- covery that made possible the modern con- crete bridges, which have almost revolution- ized the art of bridge architecture. An old saying of Scotch masons runs thus: “When a hundred years are past and gane, then gude mortar is grown to stane.” Highteenth Century Engineering The eighteenth century marked the re-birth of civil engineering as a science. After a dor- mant period covering nearly 1500 years, good roads began again to be constructed through- out Europe, improved harbors were built, water works and canals constructed and a start made at sanitation. Bridge construc- tion became more scientific, foundations were better prepared than ever before, the use of the open cofferdam for building in deep water was introduced and universally adopted, bet- ter cement was manufactured and all parts of the work show a marked improvement in workmanship, materials and tools. This was all coincident with a general ad- vance in scientific knowledge, on which the engineering profession is necessarily founded, and the establishment of schools for the training of scientists and engineers; develop- ments that made possible the tremendous material achievements of the nineteenth century. [ 100 ] BRIDGE ARCHITECTURE eS ee ae PLATE LIV—TOULOUSE, FRANCE—“THE OLD BRIDGE’’—1542-1632 ILLUSTRATING THE USE OF THE “CORNE-DE-VACHE” PHOTO FROM ‘‘GRANDES VOUTES”” SEJOURNE [ 101 ] BRIDGE ARCHITECTURE YWHHUNTIDNG “LHNOUNAd “W—28L1I—AGHYOONOD WI Ad LNOd WI—SIYVd—AT ALVI1d BRIDGE ARCHITECTURE LISI—HAANIONG ‘AINNAY NHOf—SHNVHL AHL HAAO ADGA OOTHHLYM—NOCNOT—IAT ALVId OE Wim alii): NNT Bil, 103 | [ BRIDGE ARCHITECTURE ae x Witt) him PLATE LVII—LONDON—NEW LONDON BRIDGE AS BUILT, 1831—JOHN RENNIE, ENGINEER BRIDGE ARCHITECTURE PLATE LVIII—HEIDELBERG, GERMANY—1788 [ 105 ] BRIDGE AR CGHAT EGEURE a SS SS SERIE ee Gh, RT CD We PLATE LIX—WALES—THE PONT Y PRIDD—1750—WM. EDWARDS, BUILDER—SPAN 140 FEET [ 106 | VI. THE MODERN ERA The advent of the railroad era, dating from the completion of the Manchester and Liver- pool Railway by George Stevenson, about 1830, marked the beginning of the modern era of bridge construction, and gave a tremen- dous impetus to the science thereof. Prior to this era, bridges were built more as a con- venience than as a necessity, as fords or ferries could be used by most of the vehicles then in use. The railroad locomotive, however, cannot ford a stream, and bridges became an abso- lute necessity. Unfortunately, the desire for both speed of construction and economy was so great that nearly all consideration of beauty was soon lost sight of, utility only receiving attention in the design of most railroad bridges, resulting in the disfiguration of the . landscape in many instances. In recent years, however, a reaction from this barbaric mate- rialism has set in and some of our most pleas- ing modern bridges are railroad structures. The requirements of the railroad era also caused a great change in the materials used in bridge construction, the need for long spans that could not be built with masonry arches leading to the rapid adoption of iron, both cast and wrought, and later of steel. These changes also resulted in the development of other types of bridges besides the arch; the iron beam or girder, the suspension bridge, the cantilever and the truss, including the trussed, or braced arch, came into use. In fact, modern bridge design makes free use of all of the five basic mechanical principles, the simple beam, the cantilever, the arch, the suspension cord, and the truss, whereas, prior to the last cen- tury, the arch was almost the only principle used for large bridges, the beam being used for very short and unimportant spans, and the suspension principle used only to a limited extent. Robert Stevenson, the designer of the rail- road locomotive, and engineer of many early railroads, was also the designer of three great bridges, and many lesser ones. These three bridges are the Britannia Bridge, carrying the Chester and Holyhead Railway over the Straits of Menai, in North Wales; the high level Bridge at Newcastle over the Tyne, and the Victoria Bridge over the St. Lawrence at Montreal, Canada, the superstructure of which has since been replaced by modern trusses. The Britannia Bridge The Britannia Bridge, Wales, completed in 1850, is a wrought iron tubular girder, the trains passing through the tubes. It is 1511 feet long, in one continuous tube, the longest single span being about 550 feet between sup- ports. The piers, built of sandstone faced with marble, were designed to carry suspension chains, which were included in the original design, but later omitted. Colossal lions euard the bridge heads, the work of Mr. John Thomas, an English sculptor. Originally it [ 107 ] BRIDGE was intended to place a colossal figure of Britannia over the center pier, but this was never done. The general effect is grand and simple, but marred by the unused provision in the towers for suspenders. The Britannia Bridge was the first large example of wrought iron construction, no cast iron being used. It contains 11,468 tons of wrought iron, a stu- pendous tonnage for those days. (Plate LX.) if 7 of The Bridge at Newcastle is 1372 feet long, composed of six major openings each 125 feet in the clear, spanned by iron bowstring girders carrying an upper and lower deck. Robert Stevenson was the first engineer to use this type of truss. Acar ane The Victoria Bridge was built to carry the Grand Trunk Railway over the St. Lawrence River near Montreal, at a point where the river is about 134 miles wide and was similar to the Britannia Bridge in design. Robert Stevenson, one of the greatest of the world’s engineers, largely responsible for the development of the railroad, was also one of the leading industrialists of his day, and his regard for his workmen is well illustrated by the remark he once made that “Skilled labor is the great fulerum upon which all our - social progress depends.’ He might well have included artistic progress, also. It is significant that at the beginning of the nineteenth century there was a_ wide- spread general interest in the building of iron bridges. Among others, the famous scep- tic, Tom Paine, was an ardent advocate of the iron bridge, and built, at his own expense, an experimental arch of 88!-foot span, as ARCHITECTURE a demonstration, and later was responsible for the design of an iron bridge over the Wear near Sunderland, constructed in 1796 and containing a span of 236 feet. Paine’s work was weak, however, and had to be rebuilt by Stevenson, not the only instance of correction, by the engineer, of the layman’s construc- tional errors. Prof. Pole in writing of the Britannia Bridge in 1866, closes his description with the follow- ing pertinent observation: ‘The unfettered reign of private enterprise, which, under the dictatorship of the engineer, has of late so much prevailed in this country, has been no doubt a grand source of works of commercial utility, but it has doomed us to much bitter humiliation in matters of art and taste.”’ That reign has not yet ended but is begin- ning to yield to a new era which recognizes Art as a desirable partner of Science, in Bridges, as well as in other structures. An important factor in this change is the invention and development of reinforced con- crete, allowing a very much wider use of this plastic masonry material than was formerly possible. * About 1867, M. Jos. Monier began to use *Concrele is not a new material. It was known to and used by the Phoenicians, the Carthaginians and the Romans, who developed it to a high stale as a building material, as evidenced by the existing remains of many ancient aqueducts and build- ings. Perhaps the best known example of Roman conerete con- struction yel standing is the dome of the Pantheon at Rome, 142 feet in diameter and about 1900 years old. The Roman builders used a mixture of lime rock and volcanic ash or Pozzulano in the manufacture of their cement, obtaining a material superior to most natural cements, but inferior to our modern Portland Cement, which was first made in England in 1824, and received tts name because of its resemblance in color to Portland stone, a well-known building stone of that name. [ 108 ] BRIDGE metal reinforcement embedded in concrete in order to increase its resistance to tensile stresses, and about 1889 the principle was applied to bridge construction by M. Henne- bique in France, and shortly thereafter by Prof. Melanin Austria, and by Edwin Thacher and others in the United States. Much of the best recent work in bridge architecture has been done in this material, as will be shown later. First, however, we will consider some recent works in stone masonry. Stone Masonry Bridges of the Modern Period Many very important bridges have been con- structed of cut stone masonry in both Europe and America in the modern period, from 1800 to 1925, in spite of the tremendous impetus given to the use of iron and steel during this time, often called the “Age of Steel,’ and also to the more recent impetus given to the use of concrete by the perfection of Portland Cement, leading to the frequent use of the 99 term “‘Age of Concrete,’ applied to recent construction. The greater beauty and longer life of stone masonry bridges, as compared to steel, and, at least until very recent years, to concrete, have earned for stone masonry a preference as the best material for use in the construction of permanent and monumental structures. Even today many engineers consider that concrete has not yet definitely proven that it is as permanent a material as natural stone, and it is generally conceded that a concrete has not yet been developed that admits of as satisfactory a surface treatment as may be obtained by the use of natural stones, al- ARCHITECTURE though it must be admitted that much prog- ress is being made in this respect. Among modern European stone bridges, the following are selected as worthy of especial note: At Paris, over the River Seine, the Pont de la Archeveche, the Pont Notre Dame, the Pont Au Change and the Pont Louis Phil- lippe. At Plauen, the bridge over the Syra River; at Luxemburg, the Adolphe Bridge; at Pisa, the Ponte Solferino by Vincenzo Micheli, and at Geneva, the Coulouvrenier Bridge over the Rhone. Among American stone structures, built during the last century, the following are perhaps most notable: The Harlem River Aqueduct Bridge at New York, the Cabin John Aqueduct at Washing- ton, the bridge over the Connecticut River at Hartford, Conn., and ‘the viaduct of the Pennsylvania Railroad over the Susquehanna River near Harrisburg, Pa. Modern Masonry Bridges over the River Seine at Paris (Data obtained largely from the description of “The Bridges of Paris” by Carl L. Rimmele in The Military Engineer) The Pont de la Archeveche, completed in 1828, is composed of three segmental arches of low rise as compared with the span. The central arch has a span of 17 meters, with a rise of 2.31 meters and the others 15 meters span and 1.91 meters rise. The width is 11 meters. The design is extremely plain and devoid of ornamentation. The railing is of metal with top and bottom rails and triangular pattern of webbing, very light and simple. (Plate gab [ 109 | BRIDGE ARCHITECTURE The Pont Notre Dame as it exists today was rebuilt in 1852 on the foundations of an older structure built in 1499-1507 by the Joconde Brothers, an Italian religious organization. In the rebuilding of this bridge, elliptical arches were employed for the first time in Paris bridges. There are five spans, varying slightly from 18.76 meters to 17.40 meters in length, and with a rise of from 7.5 to 7.25 meters. The width is 21 meters over all. The stone masonry of the old bridge was used in rebuilding the new. The old bridge was flanked with buildings on each side and was the property of the king, who collected tolls. Similar conditions prevailed at all of the five bridges over the Seine in Paris existing in the sixteenth century. Is it not possible that the custom of build- ing dwelling houses on bridges so prevalent during the Middle Ages was due to the in- fluence of a natural desire to live over water, inherited from our remote European ances- tors, the Lake Dwellers, or was it simply a matter of business, the density of travel mak- ing the sites valuable for shops, and the dwellings being connected with shops, as was the custom? In modern times, it has been found that such sites are not, as a rule, de- sirable for business, due to the lack of room. and the very congestion of travel, which is required by the modern spirit to ““move on”’ and not stop for shopping or gossip. The Pont Au Change, rebuilt in 1858 to 1860, also replaced an older bridge; in fact, a bridge has existed at this site since before the begin- ning of the Christian Era. The old bridge con- sisted of six spans, while the new bridge is composed of but three elliptical arches, each with 31.60 meters span and 7.22 meters rise. This bridge has the unusual width of 30 meters between parapets. In this work also, stone from the ancient structure was used in the new work. The cutwaters of the piers are circular and carried up to the extradosal lines, above which is placed a large letter ““N”’ en- circled by a wreath, the emblem of Napoleon. There is no other ornamentation. The para- pets are of the post and spindle type. (Plate LAT) The Pont Louis Phillipe, built 1860 to 1862, is also composed of three elliptical arch spans, quite similar in dimensions to those of the Pont Au Change, the center span having a length of 32 meters and the side spans 30, with rise of 8.25 meters and 7.73 meters re- spectively. The Pont Au Change is supposed to occupy the site of the Grand Pont of Julius Ceasar’s time. The only other Paris bridge existing at this ancient date was the Little Pont, as the more modern structure is still called. Other bridges at Paris belonging to the last century are the Pont St. Michel, the Pont des Invalides, the Pont de l’Alma, the latter named in honor of the victory of Alma during the Crimean War in 1854. There are four figures on the pier heads of the Pont del’ Alma, representing four contemporary types of French soldiers, a kind of applied ornamenta- tion that would seem to be proper since it conveys a significance in harmony with the memorial character of the bridge itself. This work, executed under the direction of M. de Lagalisserie, engineer, in 1855, comprises [ 110 ] BRIDGE ARCHITECTURE arches of 43 meters span and a width of 20 meters. (Plate LXIII.) Also named for a military victory are the Pont d’Austerlitz, commemorating the vic- tory of Napoleon over the Austrians, con- structed in 1801 to 1805, rebuilt in 1854 and widened in 1884; and the Pont d’Iena, named for the French victory over Prussia at lena- Auerstadt in 1806. Tron and Steel Bridges at Paris Paris also boasts, in addition to her wonder- ful masonry arch bridges, some arch bridges of cast iron notable for their beauty. Among these is the widened Pont Tournelle. The original arches are of masonry, dating back to 1654, and the roadway was widened in 1845 by addition of metallic arches on each side. Strange to say, the effect is not considered bad, a tribute to the skill of the designers. The Pont de Carrousel is, perhaps, the best known of the metallic arch bridges of Paris. It consists of three spans of 47 meters length and a rise of one-tenth of this amount. The arch ribs are built up of wood and cast iron combined and the spandrels have circular iron rings diminishing in size toward the crown. From an engineering viewpoint, this bridge is not satisfactory and the architec- tural value is not much better. The deck is 12 meters wide. The Pont d’Arcole, built in 1854, has a single wrought iron arch span of 80 meters length. The Pont Alexandre III, completed in 1900 after plans by MM. Resal and Alby, is the most ornate of the bridges of Paris, and con- sists of a single metallic arch of 109 meters span and only 6.28 meters rise, a very extreme ratio of rise to span of 1/17. Somewhat lavish use of cast Iron ornamentation on the exterior ribs and spandrels, huge masonry pylons at the corners and statuary surmounting second- ary posts, constitute the elaborate decorative scheme. It is 40 meters wide. (Plate LXIV.) A bridge at Plauen over the Syra River is the longest single span stone masonry arch in the world, having a clear span of 90 meters and a rise of 17 meters. The engineer in charge of this project was M. C. H. Leibold and the work was completed in 1903. It is called the Frederic August Bridge and consists of a single mammoth arch of the basket-handle curve type, with openings in the spandrels over the skewbacks and a simple arcade sup- porting the walks. The deck comprises a road- way 11 meters wide and two walks each 3 meters wide. Dentils are used under the cop- ing, which supports a simple stone parapet. (Plate LXXVII.) The Luxemburg Bridge is considered to be a handsomer structure than that of Plauen, and contains an arch nearly as long, 84.5 meters, and with the much greater height of 41.75 meters. This bridge, completed in 1903, spans the Petrusse River and consists of a single arch composed of two parallel stone masonry ribs, supporting four spandrel arches on each side of the center and flanked by two full centered arches, one on each side of the main span. The main arch ribs, for a short distance up from the skewbacks, are built of rough rock-faced masonry, which gives the effect of more massive skewbacks, against [111] BRIDGE ARCHITECTURE which the main arch rings of smooth-faced stone abut. The side spans each have 21.6 meters opening, and the spandrel arches 5.4 meters. The parapets are of simple spindle design, enclosing a deck having a clear width of 16 meters, comprising an 8 meter roadway, a railway track, traction track and two walks. A cartouche, the coat-of-arms of the Grand Duke of Luxemburg, ornaments the keystone. The facing material is stone masonry, but the floor is constructed of reinforced concrete. The engineer in charge of the design and the construction of this beautiful and imposing structure was M. Séjourné, Ingenieur en Chef des Ponts et Chausses of France, whois also the author of one of the most important modern books on masonry arches—‘‘Grandes Voutes.””’ (Plate LXVII.) A beautiful bridge at Pisa, Italy, known as the Ponte Solferino, completed in 1875 by the architect Vincenzo Micheli, consists of three elliptic arches delicately moulded and supported on piers having circular cutwaters. The only attempt at ornamentation consists of the carved keystones, cartouches in the panels over the piers and statues at the four large end posts of the post and spindle railing. (Plate LXVIII.) The Coulouvrenier Bridge at Geneva, com- pleted in 1895, is a fine example of good modern bridge construction, not nearly so delicately beautiful as the Ponte Solferino, but more massive. There are two main spans of segmental arches, one over a river and the other over a canal. Between them are two piers connected by a single semicircular arch of short span. Surmounting these two piers are slender, high pylons, supported on carved brackets projecting from the spandrels. This central group forms the principal architec- tural feature of the bridge and is very effec- tive. The arch rings are of rock-faced masonry, as are also the piers up to the brackets. The main arches have a clear span of 40 meters and the center arch an opening of 108 meters. The deck comprises a single roadway, 11 meters wide, and two walks with a clear width of 3.5 meters each. The balustrades are of granite, of the “‘post and spindle” type. Although this bridge is faced throughout with stone, the body of the main arches and the roadway are of concrete. The engineer was M. Constant Butticaz, and the consulting architect, M. Bonvier. (Plate LXIX.) 7 ty The Hannibal Bridge over the Vulturne in Italy is so named because it occupies the site of an ancient structure supposed to have been built by Hannibal. The modern structure was completed in 1870, and consists of a single segmental arch of 55 meters span, flanked with circular openings in the abutments, one on each side, of 9.71 meters span. The extra- dosal rings of the arches, the copings of the circular cutwaters of the piers, and the main copings, all have heavy dentils which give a very unusual character to the bridge. The engineer was M. Giustino Fiocca. A peculi- arity of this bridge and some others of the more recent Italian bridges consists in the use of a segmental ring for the exposed faces of the arch, the main section of which is elliptical. (Plate LXX11.) 7 At Kew, England, is a three-span arch bridge [112 ] BRIDGE ARCHITECTURE over the Thames, built in 1903 and named the Edward the Seventh Bridge. The arches are elliptical in section, 133 feet in span, con- structed of large voussoirs, have spandrels flush with the faces of the arch rings and no ornamentation, except the large carved car- touches over the piers. The curve of the ellipse is carried down the sides of the piers, giving the latter a very heavy, but pleasing, appear- ance. This is a simple detail that might often be employed profitably, although the cutting of the voussoirs requires considerable skill in stereotomy. The engineer was Sir John Wolfe Barry, K. C. B. (Plate LXXIr.) Another beautiful French structure is the Pont Antoinette over the Agout at Tarn, built in 1884 for railroad purposes and consisting of a simple arch span of 50 meters with five full- centered arches each side of the center, the main arch springing from between two piers of these smaller arches. The charm of this bridge is due partly to the use of differently colored stone, a light colored stone for the main arch ring, the coping and retaining walls, while the balance is of a much darker stone, accentuating the main features. The engineer in charge was M. Robaglia. (Plate EXXIv:) In Austria, at Vorailberg, a railroad arch bridge spans a deep gorge with a single mas- sive arch ring of uniform thickness, support- ing four spandrel arches on each side. The pleasing effect of this bridge is obtained by the use of large stones of irregular size and rough rock-faced masonry, all suggestive of rugged strength and harmonizing with the rugged character of the surrounding land- scape. The span is only 41 meters and the only parapet a pipe railing. The design is typical of many others on Austrian railways. (Plate LXXV.) At Orleans, France, over the Loire, is another railway bridge, built in 1906, consisting of seven equal spans of 43.85 meters each, of open spandrel design similar to many other structures, but distinguished by the use of brick for the spandrel walls, and also for the panels of the parapets. The contrast of color is sharp, much more so than in the case of the Pont Antoinette. The engineer in charge was M. Renardier. (Plate LXXVI.) A bridge over the Moselle, in Lorraine, com- pleted in 1905, embraces some features of architectural design worthy of note. This structure is of the common open spandrel, segmental arch type, the distinctive features being the treatment of the pilasters over the piers with dressed stone edges and rock-faced panels and the use of a very simple metal railing with double posts over all piers and columns. The engineer was M. Blumhardt. (Plate LXXVI.) The Séjourné Bridge over the Pedrouse, named in honor of its designer, M. Paul Sé- journé, consists of masonry arches 65.2 meters high and was built in 1911. It is remarkable for its great height. (Plate LXV1.) The Puente Nuevo at Ronda, Spain, a high masonry arch over a deep gorge, designed by Jose Martin Aldeguela, is a unique structure, the abutments being carried up the sides of [113] BRIDGE ARCHITECTURE the gorge in perpendicular lines. The archi- tect was killed by a fall from his work while under construction. Older Roman and Moor- ish bridges cross this gorge at lower levels. (Plate LXXIX.) “The High Bridge’ at New York was built in 1837 to 1842 as an aqueduct for the Croton water supply system of the city under the direction of John B. Jervis, engineer. It con- sists of 16 full-centered (semi-circular) arches of 80 feet span each, on high piers. The total length is 1460 feet and the height above the river is 116 feet. The design is simple, the principal charm of the structure lying in its proportions and in the fine workmanship of its dressed stone masonry. It is now (1927) found necessary to remove some of the piers of this bridge on account of interference with navigation of the river, an alteration which it is hoped will not mar its beauty. (Plate LXXx.) The Cabin John Arch, near Washington, D.C., was completed in 1864 by General Meigs, U.S. A. This structure is part of the water system of Washington, D. C., and consists of a single arch of 220 feet opening and 101 feet rise. It is chiefly noted for its size, although a. much more distinctive feature is the use of a double arch ring, the inner or lower ring of dressed stone, and an upper or extradosal ring of rock-faced stone. (Plate LXXXI.) One of the most beautiful structures in Amer- ica is a bridge over the Connecticut River at Hartford, Connecticut, completed in 1908, and known as the Memorial Bridge. The length of this bridge is 1192 feet and its width is 82 feet. The nine arches have an opening of 119 feet each, are elliptical in shape, built of cut granite, smooth faced. The piers have triangular cutwaters, the spandrels are flush with the faces of the arch rings and the coping is a simple projecting band of granite unrelieved by dentils or otherwise. The para- pet is a solid wall, capped with a plain coping. There are two enlarged piers with projecting bays. Extreme simplicity is the keynote of this bridge, yet the effect is very pleasing and possibly unexcelled by any similar structure. One cannot study the architecture of the masonry bridge without being impressed with the great beauty of the elliptic curve, when used for such low-lying structures as this. The design is credited to Mr. A. P. Boller, consulting engineer, in collaboration with Mr. E. D. Graves, chief engineer, and Mr. E. M. Wheelwright, consulting architect. (Plate LXXXII.) American Railway Stone Arches Many fine bridges of stone masonry have been built in America by the various rail- roads, such as the bridge over the Susque- hanna River near Harrisburg, Pa., on the Pennsylvania Railroad, consisting of a long series of equal span, semicircular, solid span- drel arches of sandstone. (Plate LXXXIII.) On the lines of the New York Central Railroad, especially that part formerly known -as the Lake Shore & Michigan Southern Railway, are many fine examples of cut-stone masonry arches, typical of which are the bridges over Black River, at Elyria, and at Berea, Ohio, both high arches having solid [114] BRIDGE ARCHITECTURE masonry spandrels with no earth fill. These bridges were built of the famous Berea Sandstone, found in northern Ohio, and ex- tensively used for bridge construction, as well as for buildings. At Elyria, Ohio, there is also an unusually flat stone highway arch, having a rise of about 28 feet, for a span of 155 feet. It was built in 1886 of Berea Sandstone, about the same time that the railway bridges mentioned were constructed. (Plates LXXXIV & LXXXV.) At Cleveland, Ohio, are some unusual ma- sonry bridges, built about 1900 after designs by Architect C. F. Schweinfurth and carrying city streets over the Rockefeller Parkway. The material is sandstone for the facing, although some of the arches have rings of brick. The designs are quite unique, a feature being the omission of the usual copings and parapets. (Plates LXXXVI & LXXXVII.) Timber Bridges lif the early decades of the nineteenth century, many timber arch bridges were built in the United States. Timber was plentiful and there- fore this type of structure was economical in | first cost, and, indeed, many of them served nearly a century of usefulness. Little can be claimed for them as objects of beauty, yet some of them possessed a picturesque charm. Among the more famous was that over the Delaware River at Trenton, consisting of 203- foot spans, built in 1804, and replaced in 1875 by an uninteresting steel truss bridge. The Collossus Bridge over the Schuylkill at Phila- delphia, quite noted at one time for its clear span of 340 feet and a rise of only 38 feet, was built in 1812 and destroyed by fire in 1838, a fate that befell many, if not most of these timber structures. The so-called “Y” Bridge at Zanesville, Ohio, located at the junction of the Mus- kingum and Licking Rivers, another famous timber structure, was built about 1820 and replaced with a concrete bridge in 1900, serv- ing this community faithfully for eighty years. The most ambitious timber arch bridge ever attempted, however, was built near Baden, Germany, in 1760 by the Brothers Gruben- man, noted bridge builders of that day. This structure boasted the unprecedented length of 360 feet in a single span. (Plate LXXXIXx.) [115 ] TURE 5 el HITEC aI A AR( E ‘ I BRID(¢ MUOA MAN ‘AOTAUTS OLOHd SUSHSITANd WOUd OLOHA YAANIONGA “NOSNAADLS LYAGOU—0S8I—ADCIYA HVINGAL VINNVLINVE—SHTIVM—XT1 ALVId [ 116 ] BRIDGE ARCHITECTURE Sek a SluVd ‘UNASSVAAT AP OLOHA 8c8L LILNA—AHOHAKHOUV VWI Ad LNOd AT—SINVd—IXxl ALVId FAAS ARCHITECTURE BRIDGE ae pert SIuvd ‘UNASSVAVI Ad OLOHd 0981 LIINA—HONVHO OV LNOd WI—SIYVd—IIXT ALVId {OE [ 118 ] mI ae ee | oon Spire BRIDGE ARCHITECTURE PLATE LXIII—PARIS—PONT DE L’ALMA—1860 EkLos| BRIDGE ARGHITECTURE 0061 CHULA Td NOO—SYUAANIONY ‘AGTV ¥ TVSHY WA—II SYGNVXATY LNOd—SIMVd—AIXT ALV Id w Ai f i} BRIDGE ARCHITECTURE S98I—SHAANIONG “ADVNALAG-SYATIIA ¥ NIMANS ‘AYYAId WOSSVE WA—TINALAV.d LINOd—Slu¥Vd—AX'T ALV Id [121] BRIDGE ARCHITECTURE ASNOUdHd AHL YHAO HOGIYA—AONVYA—IAXT ALVId [ 122 ] BRIDGE ARCHITECTURE €061—YHANTO ‘ No ‘AN YOOLaS “W ASSQULAd AHL YAAO AHdTOGV LNOd—OYuNdNaXNT —HAXT ALVId 123 ] | BRIDGE ARCHITECTURE IMVNITV AM OLOHd $28I—LOALIHOUV ‘TIAHOIN OZNHONIA—ONIYAATIOS ALNOd—ATVLI ‘VSId—IIAXT ALWId [124 ] TURE C HITE oO A ARC BRIDGE LOALIHDYY DNILTOSNOD ‘YHIANOd “N—YAANDONG ‘ZVOILLOAG LNVLSNOD “IW c68I—ANOHY AHL YAAO YHINAYANOTOAOD VI Ad LNOd—ANVTYAZLIMS ‘VAHNAD—XIXT ALVId [ eeeenereten ree erecta cea [ 125 mT aT tn Didnt, ed r sl BRIDGE ARCHITECTURE ANUNOL AS WOUT OLOHd 16Ll LING HAC TH AHL LHAOVS Ad Ad GNOOYWOHHOU NT ADGIMA—LAODV AHL WAAO SHOCINYA—AONVUA ‘UAVAVI-XX1 ALY Id 6 | [ 12 BRIDGE ARCHITECTURE NVdS SYU.LAIN jANYNOL AS TAVd “W WOW OLOHd ¢19—?88I_YHHNIONA VITOVEOY W—LAOOV.T YM “MAVAVT ad LNOd—aONVYA “YAVAVI—IXXT ALVId 127 | [ ARCHITECTURE BRIDGE jANUNOL AS TAVd “W WOU OLOHA YHANIONG “VOOOIT ONLLSOID (W—028I—-ANYALINA AHL YAAO ADGINE TVSINNVH AHL—XIVLI—IIXXT ALVId BRIDGE ARCHITECTURE ADIAUAS OLOHd SUMHSITANd WOUA OLOHA YHANIONA ‘AYHVE AAVTIOM NHOL YIS—S06I—SHNVH.L AHL YAAO ADAYA TA GHYVMGH—ANVTONG ‘MAM—HITXXT [ 129 ] TURE ARCHITEC E ~ vf BRID¢ JANUNOL AS 1NVd "W WOUdA OLOH V88I—YAANIONG “VITOVEOU “(N—LONODV.1T HAS ALLANIOLNVY LNOd—dONVYA ‘NYUVL—AIXX' ALVId [ 130 ] BRIDGE ARCHITECTURE PLATE LXXV—VORAILBERG, AUSTRIA—THE WALDLITOBEL BRIDGE—1884 PHOTO BY M. M. WURTHE & SONS, SALSBURG BRIDGE ARCHITECTURE JANUNOL, AS TAVd “W WOUd OLOHA YAANIONA ‘YAIGUVNAY “W—906l LTING—aUIOT AHL YAAO ANGINA AVM TIVU—AONVUA ‘SNVATHO—IAXXT ALVId $ wt aaieaniinseeileaiamiion aS eas 6| | le GE secees . | 4 BRIDGE ARCHITECTURE ae yews a PLATE LXXVIIL—PLAUEN, FREDERIC AUGUST BRIDGE OVER THE SYRA RIVER—1905 SPAN, 90 METERS—CG. H. LEIBOLD, ENGINEER [133] BRIDGE -ARCHITECTURE PLATE LXXIX—RONDA, .SPAIN—PUENTE NUEVO DEL TAJO DE RONDA—EIGHTEENTH CENTURY JOSE MARTIN ALDEGUELA, ARCHITECT PHOTO COPYRIGHT BY N. PORTUGAL, MADRID [134 | ARGHITECTURE BRIDGE YHANI ye SI ‘OO ONIHSITANd LIOVLAG AHL AM GHLHOIMAdOD OLOHd AYae “H NHOf— i s “eae Th eh kaa ok ok at kh thal ad sll a ee ee ee Pik th salt hth th ah sah kt lt kkk a ih ahh lh at a sek ah ah ak ahah De i aid ah ed ad : i ; ee id ated td j | Vie j — rd sy mon id ee neti li cblaececemnemn are nat sibanceepise eh, {ae BRIDGE ARCHITECTURE “M ‘f'M AM OLOHd 006 GHOVIdHY—0e8T LIN SHUHATHY ONIMOIT ¥ WOONTHSOW AHL YAAO HDCT YAAWILL GHYAAOO—OIHO “A TIIASHNVZ—XIXXX1 DLV 1d [ 144 ] IRON AND STEEL ARCH BRIDGES HE Railroad Age, starting with tremen- dous impetus in the fourth decade of the nineteenth century, demanded bridges of longer span, designed for heavier loads, than could be built economically of stone masonry or timber, and this demand was met by a vast improvement in the quality of iron and later of steel, as well as in the processes of manufac- ture, which made possible the production of greatly increased quantities of this material at much lower cost than before. At first, cast iron was extensively used for bridges of the arch type; then wrought iron chains and later wire cables were provided for bridges of the suspension type, while still later these types were largely superseded by the girder or beam and the articulated truss. It is unfortunate that this evolution, while progressive from a_ strictly engineering or utilitarian standpoint, was retrogressive from the viewpoint of architectural merit, this re- trogression being due not so much to the type evolution as to the psychology of the times, materialism displacing all higher motives. The first iron bridge, erected in 1779 over the Severn River in England at Coalbrook- dale, had a cast iron arch span of 100 feet. Possibly the three best examples of the cast metal arch are the old Southwark Bridge in London over the Thames, the great Eads Bridge over the Mississippi River at St. Louis, and the Alexander HII Bridge over the Seine at Paris. The Southwark Bridge, completed in 1819, had a center span of 240 feet and side spans of 210 feet each, constructed of cast iron arches. The design and execution was by John Rennie, the engineer of the Waterloo and New London Bridges. John Rennie’s masterpiece has recently been replaced by a more modern structure, neces- sitated by the demands of heavier traffic as well as by the settlement of the piers which made the old structure unsafe. This new struc- ture, completed in 1921 from designs by Messrs. Mott, Hay and Anderson of London, has five steel arch spans of 123 to 150 feet clear opening as compared with the three spans of 210 and 240 feet of the old bridge. The plan was developed to conform to the openings in adjacent bridges, resulting in less interference with the river current. This new Southwark Bridge is a beautiful structure and is a good illustration of what can be accomplished by a combination of steel arches and masonry piers. There is no elaborate ornamentation, the piers being car- ried above the roadway level to form a series of simple pylons. Sir Ernest George, A. R. A., collaborated with the engineers in the design of the mason- ry piers and abutments. (Plates XC & XCI.) The second bridge to be built over the Thames at London was the Westminster Bridge, completed in 1750 as a masonry [ 145 ] BRIDGE ARCHITECTURE structure of thirteen arches, designed by a French engineer, Charles Labelye. It was of the view of the city from this bridge that Wordsworth wrote, “Earth has not anything to show more fair.” Labelye’s Bridge was characterized by unusually high parapets, a feature that a French writer (Parisian) de- clared was intended to prevent the Londoners from committing suicide. Possibly his opin- ion of the view did not agree with that of Wordsworth. The old Westminster Bridge lasted a little better than a century, being replaced by the existing steel structure in 1862. Its failure was due to the gradual undermining of its foundations by the river, a fate that also befell the Blackfriars Bridge (the third to be built across the Thames, in 1769, by Robert MylIne). And now the river has at last (1926) conquered Rennie’s Waterloo bridge. (Plate XCII.) 7 y 7 The Blackfriars Bridge was rebuilt in 1865, under the direction of Joseph Cubitt, engi- neer, and was widened in 1908 by Sir Ben- jamin Baker. vA w 7 At Constantine, Algeria, there is a fine cast iron arch bridge, completed by the French in 1865 and bearing the inscription of Napoleon Ill. The architect in charge was M. Martin. (Plate XCIII.) The Alexandre HI Bridge at Paris, built also with cast steel ribs, in 1899, has already been described. (Page 111.) The famous Eads Bridge at St. Louis was built in the years 1868 to 1874 by James B. Eads, one of America’s most noted engineers The arch ribs are of cast steel and have a clear span of 520 feet with a rise of 47 feet for the central arch and a clear span of 502 feet for the flanking spans. The construction of this bridge was considered to be a great engineer- ing achievement in its day and it has safely carried the greatly increased loads of modern highway and railroad traffic. Its graceful arches are a pleasing contrast to the more modern trusses of its neighbors. “Although some of its details have been altered and strengthened, the main frame of braced arch tubes is still intact as originally constructed and is carrying present day traffic in volume and weight far beyond the designs and expectations of its builders. This unusual record is a fine tribute to the work and per- sonality of James B. Eads.* About 600,000 passenger and freight cars and over 50,000 locomotives cross the bridge each year. The bridge cost about $7,000,000.” (C. E. Smith, before the American Railway Bridge and Building Association, 1924.) (Plate xcrv.) *Mr. J. B. Eads, the eminent American engineer who con- ceived and executed this noble project, against great odds, made the following statement in the course of an address delivered in 1871. The sentiment expressed therein seems to be worthy of repetition here. He was speaking of the Missouri River. “My experience of this current has taught me that eternal vigilance is the price of safety, and constant watchfulness is one of the first requisites to insure success, almost as much as knowledge and experience. To the superficial observer, this stream seems to override old-established theories, and to set at naught the apparently best devised schemes of science. But yet there moves no grain of sand through its devious channel, in its course to the sea, that is not governed by laws more fixed than any that were known to the code of the Medes and Persians. No giant tree, standing on its banks, bows its stately head beneath these dark waters, except in obedience to laws which have been created in the goodness and wisdom of Our Heavenly Father, to govern the condi- tions of matter at rest and in motion.” [ 146 ] BRIDGE ARCHITECTURE The Whipple Truss Cast iron was extensively used in the early part of the nineteenth century, in Amer- ica, for the compression members of truss bridges. Hundreds of structures of the arched truss or “Bowstring” type, with the upper chord curved in form and made up of cast iron segments, while the lower and _ inter- mediate members were of wrought iron, are still in use. This type of arch was known as the Whipple Truss, after its inventor, Squire Whipple, of Utica, New York, to whom be- longs the honor of having been the first engi- neer correctly to analyze the stresses in the articulated truss, in his book on bridge build- ing published in 1847. For centuries, engineers and architects had been building bridges without much mathematical knowledge of the stresses involved, but relying simply upon past experience and good judgment in pro- portioning the various members composing the structure. These old Whipple arch bridges are better looking than many more modern types of metal bridges, but are being rapidly displaced by structures designed for heavier loads. Bowstring trusses of this type have been built up to 187 feet span. (Plate xcv.) During the nineteenth century, material improvements were made in the processes of manufacturing wrought iron, and in the last quarter of that century wrought iron began to be displaced by steel. These improvements rendered possible the economical use of wrought iron and steel for bridge construc- tion of all types, the beam or girder type, the cantilever type, the arch, the truss and even the suspension type. This strong and inexpensive material made possible the con- struction of much larger spans than hereto- fore. In the case of the arch type, spans have constantly increased in length, culminating in such a structure as the Hell Gate Arch at New York with its single span of nearly a thousand feet. Some of these great modern steel arches are structures of great beauty, as the Washington Bridge at New York, the Garabit Viaduct in France, the bridge over the Rhine at Bonn, Germany, the Upper Steel Arch at Niagara Falls, and a bridge over the Aar at Berne, Switzerland. Some more modest structures of the steel arch type are also worthy of note, many by reason of the artistic treatment of the combination of masonry and steel, as exemplified by the Charles River Bridge at Boston, and by some bridges on the Nickel Plate Railway at Cleveland, as illustrated in the plates. The Washington Bridge at New York, over the Harlem River, was completed in 1889. This beautiful structure consists of twin arch spans 508 feet 9 inches in length each, and having a rise of 83 feet 4 inches. The arch ribs are segmental plate girders, supporting nu- merous vertical posts which carry the road- way floor. The designer was Wm. R. Hutton, chief engineer, with E. H. Kendall as consult- ing architect. The designer of this bridge ob- tained a pleasing symmetrical design in spite of a very unsymmetrical profile. (Plate XCVI.) The Garabit Viaduct over the Truyere, France, built in 1884, carries a single track railroad over a deep and rocky gorge. The graceful parabolic arch is a latticed truss, deeper in the center than at the ends, and has [147 ] BRIDGE ARCHITECTURE a span of 166 meters with a rise of 52 meters. The arch rib carries but two posts and two more are carried by the abutments. These posts have a pronounced batter and are latticed like the arch ribs, as are also the trusses. The effect is that of extreme simplicity and harmony in steel. The design is due to M. Eiffel. (Plate XCvil.) The Rhine Bridge at Bonn consists of a single long and high steel arch flanked by shorter low arches. This bridge was completed in 1897. The main span is 188 meters in length, be- tween piers, while the side spans are each 96 meters long. The main span is a trussed steel arch deeper at the ends than in the center, segmental in curvature, and carrying a road- way most of which is below the arch and sus- pended therefrom. The flanking arches are of the deck type. Features of the Bonn Bridge are the beautifully proportioned piers, sur- mounted by Romanesque towers at the ends of the main span and the cast iron ornamental portals and railings. Bruno Mohring, of Berlin, was consulting architect for this project. (Plate XCVIII.) A steel arched highway Bridge at Berne, Switzerland, over the River Aar, completed in 1898, is similar in conception to the Garabit Viaduct with this difference, that the latticed arch ribs are deepest at the springing, and decrease in thickness to a comparatively shal- low thickness at the crown, just the reverse of the Garabit Bridge. The arch ribs support eight high, tapered, latticed columns, which carry latticed trusses. The main arch is 114.86 meters span by 31)% meters rise. A comparison of this design with that of the Niagara arch is very much in its favor for architectural merit, although doubtless this type is somewhat less economical of material. The credit for the design of this very handsome bridge belongs to A. and H. Bonstetten, engineers, and B. H. Von Fischer, consulting architect. (Plate XCIX.) At Ruidesheim, Germany, there is a railway bridge over the Rhine that comprises two steel arches flanked by simple steel trusses, so arranged that they seem to fit the regimen of the stream unusually well. (Plate c.) The Upper Steel Arch at Niagara Falls, offi- cially called the Niagara Falls and Clifton Bridge, completed in 1898, carries a highway over the raging torrent of the Niagara gorge just below the great falls, with a single span of 840 feet and a rise of 137 feet. The arch is parabolic in curvature and the main span is flanked on each end with a shorter inverted parabolic arched truss. The main arch rib is hinged at the ends only, increasing in depth from the ends to the center, and is trussed, carrying vertical posts stiffened by horizontal braces. The engineer in charge was Mr. L. L. Buck. (Plate cir.) The great steel arch bridge of the New York Connecting Railway, carrying its double track over Long Island Sound at Little Hell Gate, was completed in 1916, after designs by Gus- tav Lindenthal. This magnificent structure comprises a single steel arch of 977% feet span, flanked by a high trestle on each side, from which it is separated by massive masonry [ 148 ] BRIDGE ARCHITECTURE towers serving as the abutments of the arch span. The main arch rises to a height of nearly 300 feet above the river. The intrados is parabolic in curvature while the extrados curve is reversed near the abutments, where the depth between the intradosal and extra- dosal curves becomes greatest. An idea of the magnitude of this structure may be obtained from the quantities of material required, about 210,000 tons of steel and 108,000 yards of masonry being used. (Plate Crt.) The Cambridge Bridge at Boston, Massachu- setts, completed in 1908, is one of the finest steel arch bridges in the world. The present structure replaces the old West Boston Bridge, which Longfellow immortalized in “The Bridge,” and consists of eleven spans of steel plate arches abutting against massive granite piers. The center or channel span of 188% feet is flanked by large piers carrying ornamental stone towers. The engineer-in- chief was William Jackson and Edmund Wheelwright was consulting architect. The cost was about two and one-half million dollars. (Plate civ.) Many small steel arch bridges of merit have been built, most of them, of course, with no attempt at architectural treatment. Among those that show architectural study are some street crossings of the Nickel Plate Railroad in East Cleveland, Ohio, designed by the late A. J. Himes. When compared with the cus- tomary designs of such structures, these bridges deserve commendation. (Plate Gy.) Two graceful steel arch bridges, one in Riverside Cemetery, Cleveland, and the other near Cleveland, constructed in the early nine- ties, are the work of the late Frank C. Osborn of that city. (Plate CVI.) A German bridge over the Rhine at Worms, completed in 1901 by the engineers Schneider and Frintzen, and consisting of three steel arches, at the ends of which have been erected elaborate portal towers, has a distinctive character. (Plate CVI.) The new bridge at Fortieth Street, Pittsburgh, known as the Washington Crossing Bridge, consists of three steel arch spans, supported by well-proportioned concrete piers. The Sixteenth Street Bridge at Pittsburgh, recently completed, comprises three trussed steel arches of the overhead type and here again the charm of the structure is due largely to the design of the piers and abutments. Mr. V. R. Covell is the engineer in charge of these Pittsburgh bridges and Messrs. Warren & Wetmore were the architects for the Sixteenth Street Bridge and Benno Janssen for the Fortieth Street Bridge. (Plates CVITI SC EXs) [ 149 ] BRIDGE ARCHITECTURE NOGNOT ‘AONADV OIHdVYIOLOHd TVUANGAD AG OLOHd LOALIHOYY “ADYORD LSHNYA YIS SHAANIDONA ‘NOSHHONYV ¥ AVH ‘LLOW—I26l GHLATANOD—HOCIYE AYVMHLNOS MAN AHL—NOGNOT—OX ALVId pane? Bien THATS prAaue Ron re mT it) Twit 5 Y Beigel : — - He - =e =e ES. DS iki were bse? satan — simone GAN wat ¢ THES Te «FRE 1B Se Nef ltt Rs 2 Ree i. \ ieee ¥ 9 ve ' * . s Ry . u ~ “s x “ HLL cu BRIDGE ARCHITECTURE SYAANIONA ‘NOSUHANV ¥ AVH NOGNOT ‘AON@DV DIHdVYSOLOHd TVYANAS WOWd OLOHd LOALIBDYY “ASYOHD LSHNYA IS ‘LLOW—I26I—SAWVHL AHL YHAO AHOCTYA MYVMAHLNOS MAN—NOCNOT—IOX ALVTd [151 ] BRIDGE ARCHITECTURE [ 152 ] PLATE XCII—LONDON—WESTMINSTER BRIDGE OVER THE RIVER THAMES—1862 PHOTO FROM GENERAL PHOTOGRAPHIC AGENCY LONDON BRIDGE ARCHITECTURE S98I— LOULIHOYUVY NILYVIA ‘W—HOdITHd VUVINVY TH AOIAYAS OLOHd SHAHSTIIANd AHL AG LHOIMAdOD VIHHOTV ANILLNVLSNOO—III r yX HLV Td 153) | [ BRIDGE ARCHITECTURE his h ‘OD ONIHSITANd LIOULEA WOUd OLOHd YAANIONG ‘SAVa “a ‘S¥f[—?r.8I—YAATY IddISSISSIN AHL YAAO AODGIUA SAVA AHL—OW ‘SINOT \LS—AIDX ALWId + = = ae: et b BSS EAE eT TT iar | = ee Be fe Pe r arn &— ee er {{ Bie ta | = vores SRB EE \Ee ie a a aT a g 3 é ; [ 154 ] BRIDGE ARCHITECTURE "Mf *M XG OLOHd 0S8I-SULVIS GALINA NYALSVA—ad AL ATddIHM—HOUV «.ONIMLSMOG,, TVOICAL—AOX FLV Td BRIDGE ARGHLT BOTURE ‘OO ONIBSITANd LIOULAG AHL AW GALHSIYAdOO OLOHd LOULTHOYY ONILTOSNOD “TIHGNAM “H “A “YAANTONG AaIHD ‘NOLLOH ‘YH “WM HOV SHHONT 6 LAAA 80¢ SNVdS—688I—YA ATHY WATYVH AHL WAAO ADGA NOLONIHSVM—MHOA MAUN—IADX ALVI1d 156 ] [ BaD GE SA bl TEC WT sis NGINEER—1884 4 4 EIFFEL, I ‘CVII—FRANCE—GARABIT VIADUCT—M. 4 PLAT ARCHITECTURE BRIDGE LOULTHOYV ONTLINSNOD ‘NITHAd “ONTYHOW ONNYA 4681 GHLA TA NOD—ANIHNY AHL YHAO ADGIYA HOYV TAALS—ANVNYAD ‘NNOP—IIIADX ALVId ae ae ed eet RiP ipso [ 158 ] BRIDGE ARCHITECTURE LOALIHDYY “UAHOSTA NOA *H “& SHAANTONA ‘NALLALSNOd NOA “H ¥ “¥—868I—-HVV AHL YAAO AOGIMA—ANVTYAZLIMS “ANYHA—XIOX LV Id 159 | [ HITECTURE ~ A ARC BRIDGE ‘D) ‘V DUFANUNN-DUNESDAV WIMAVANANIHOSVA WOud OLOHd ANIHY AHL YHAO HOCTYA AVMTIIVU—-ANVNYED ‘WNIHHSAGNY—) ALVI1d al oe OE a ames wa ; : PORES rn gt > - anaes Oa ceo gam A, be, . RANT AaNrraNrnewre nt” Ws » % - Se a x% : 3 = Ma Bp SNA ANESANTSAIS oS 1 SP USUSENNSINN,89, SS Nhe Fay, BAA ey AP : F 4 Beiter Rhett [ 160 ] BRIDGE. ARCHITECTURE “DV OYWEEANYON-DYaAESDNV MIMAVINANIHOSVW Ad GANDISHd “NIOM ‘SND AWG OLOHd NYAGOW—ANTHY AHL YAAO AOGINA AVMHDIH GNV AVMTIVE—ANVINNYHD ANDOTOD—ID ALVId 161 | | BRIDGE ARCHITECTURE "Mf *M XG OLOHd 868I—YHANIONG “MONG “I “I—aOCIUd NOLATITO-VUVOVIN— A ‘N ‘STTIVA VHUVDOVIN—IID ALVTd [ 162 ] BRIDGE ARCHITECTURE ‘OD DNIHSITANd LIOULAG AHL AM GALHDIVAdOO OLOHA YHANTIONG “TVHLINAGNIT AV.LSND—916I—aDdIad ALVD TIHH—A “N “WHOA MAN—IIIO ALVId eww WM vwrirosiuds jeatn toe ’ Bere [ 163 | BRIDGE ARCHITECTURE LOULIHDYY DNILTASNOD “LHDTYUMTHSHM GNOWGA “YaHANISNA AaTHD ‘NOSMOVE WVITIIM 8001 —YAATY SHUTUVHD HHL YAAO ADGA MOTICADNOT AHL—SSVW ‘NOLSO@—AID ALY Td [ 164 | BRIDGE ARCHITECTURE na ee = PLATE CIV-B—DETAIL—LONGFELLOW BRIDGE DETAIL—LONGFELLOW BRIDGE [165 } BRIDGE ARCHITECTURE YaANIONG ‘SHIWIH ff “V—'AU “I “LS ¥ ‘D0 “A ‘(N JO DNISSOWD LAAULS—OIHO ‘GNVWTHAATO LSVA—AD ALVTd BRIDGE ARCHITECTURE “0 % 3 4 2 ‘ti a re H r oe cg PLATE CVI—CLEVELAND, OHIO—HIGHWAY BRIDGE IN RIVERSIDE CEMETERY—ABOUT 1896 FRANK C. OSBORN, ENGINEER [ 167 ] BRIDGE: AR GHITEGIRE PLATE CVI-B—CHAGRIN FALLS, OHIO—STEEL ARCH BRIDGE DESIGNED BY FRANK CG. OSBORN ARCHITECTURE BRIDGE NAZLNIYH 8 YHCTHNHOS °} =. H ‘SU H ‘3 °V DYAENYON-DYaESONV MIYAVANANIHOSVW WOYA OLOHd ANIONA—L06I—ANIHY AHL YAAO ADGINA AVMHDIH—ANVINYAD * YHOM—IIAD HLV Id BRIDGE ARCHITECTURE PLATE CVIII—PITTSBURGH, PA.—FORTIETH STREET BRIDGE OVER THE ALLEGHENY RIVER—COMPLETED 1924 V. R. COVELL, CHIEF ENGINEER. BENNO JANSSEN, ARCHITECT fata PLATE CIX—PITTSBURGH, PA.—SIXTEENTH STREET BRIDGE OVER THE ALLEGHENY RIVER—COMPLETED 1923 V. R. COVELL, CHIEF ENGINEER. WARREN & WETMORE, ARCHITECTS [ 170 ] ae MODERN SUSPENSION BRIDGES HE Suspension Bridge is the natural re- verse of the arched type, the arch turned upside down, so to speak, and is one of the earli- est types, having been used extensively by Asi- atic peoples since prehistoric times. Until quite recently, however, the type was undeveloped, due primarily to the lack of proper materials for heavy construction. During the last cen- tury it has been highly developed by Telford in England, Ellet and Roebling in the United States, and others. Some of these structures are beautiful and worthy to be classed among our great monumental bridges, notably the three incomparable spans over the East River at New York, and the recently completed Philadelphia-Camden Bridge. As the suspension type of bridge necessarily utilizes more perishable materials in its con- struction as compared to the masonry arch, no ancient structures of this type have come down to us intact. There exist in many places, however, structures that have been main- tained without change of design or construc- tion for many centuries. Among these are the suspension bridges of Asia, as an illustration of which we have selected a bridge located in northern Sze-Chuan, China. This bridge is constructed of cables of woven bamboo, sup- ported on and anchored to heavy masonry piers, which carry timber and stucco houses. (Plate VII.) At Newburyport, Massachusetts, there is an old suspension bridge, built in 1810, and still in use, although similar to many other bridges that have outlived their usefulness and been replaced by stronger, and often uglier, types. This bridge was built by one John Templeton, and has a span of 244 feet. The cables or suspenders are made up of chains. It has just recently been repaired and rebuilt by Prof. George W. Swain, after more than a century of service. (Plate Cx.) One of the most famous suspension bridges in the world is the Menai Straits Bridgein Wales, built by Telford and completed in 1826 after seven years’ work. This was at that time the largest suspension bridge yet built, having a main span of 579 feet with approaches of high massive masonry arches. The length over all is 1710 feet and there are two driveways 12 feet wide each and one walk 4 feet wide. (Plate GX1.) Suspension Bridges at Budapest Among European bridges notable for their beauty are two suspension bridges at Buda- pest over the Danube. The more recent bridge of Budapest is known as the Elizabeth Bridge and was completed in 1905 after designs by A. Czechelius, with M. Nagy as collaborating architect. The main span is 290 meters in length and the length over all 920 meters. Massive masonry pylons over the anchorages form the principal architectural feature. The older and more beautiful structure, known as the Kettenbriicke, has a span of 203 meters [171 ] BRIDGE ARCHITECTURE and was completed in 1849 after plans by W. T. Tierney Clarke. It has well-propor- tioned masonry towers and abutments, the latter with carved lions ornamenting the end posts. While not the equal of some of our recent American bridges in magnitude of span, there can be no doubt of the superior architectural value of these two structures. (Plates CXII & GXITe) fee Tey The practical development of the suspen- sion bridge to suit modern requirements has taken place in America, and many of the American bridges possess also aesthetic merit, inherent in the natural gracefulness of the type, when well designed. Some of the earlier and more spectacular structures, such as the bridges over the Niagara gorge, have dis- appeared, and have been replaced by more rigid types which are doubtless more util- itarian, but unfortunately somewhat less pleasing to the eye. The grandfather of this type in the United States is the old bridge over the Ohio River at Wheeling, West Virginia, constructed by Col. Ellet in 1846 to 1849, as a link in the National Highway from Washington to the West. It has a span of 1010 feet. During a storm in 1854, the stiffening trusses were wrecked, a lesson that led to a careful study of this essential part of the design which made possible later the great and successful bridges at New York. This bridge was recon- structed in 1862 by Col. John A. Roebling and is still in service, a delight to look upon. Col. Roebling later completed a similar bridge, having a span of 1260 feet, across the Niagara River below the falls. This structure was re- built, with heavier cables, in 1889, and still later was replaced with a steel arch. This latter became a famous bridge, due largely to its spectacular location at the greatest honey- moon resort in North America. New York—Brooklyn Bridge Col. Roebling then undertook the construc- tion, as engineer-contractor, of the Brooklyn Bridge over the East River at New York, which was completed, against great odds, financial as well as engineering, in 1883. This huge structure, justly celebrated as one of the greatest achievements of engineering, also possesses artistic merit of a high degree. Possibly its designers had little intention of erecting a work of art, but of the result there can be no doubt. No sculpture, no ornamen- tation of any kind is used, or needed. Its simple and dignified design is all that is necessary. Mr. Roebling made a report to the president and directors of the Bridge Com- pany in 1867, which closed with these words: “The contemplated work, when constructed in accordance with my designs, will not only be the greatest bridge in existence, but it will be the great engineering work of this continent and of the age. “Its most conspicuous features—the great towers—will serve as landmarks to the ad- joining cities, and they will be entitled to be ranked as national monuments. As a great work of art, and as a successful specimen of advanced bridge engineering, this structure will forever testify to the energy, enterprise and wealth of that community which shall secure its erection.” Surely this great engineer Bree BRIDGE ARCHITECTURE possessed the imagination of a genius, as well as the feeling of the artist. To quote again from his writings, ““Honesty of design and execution, next to knowledge and experience, most surely guarantees professional reputa- tion.’ Most excellent advice to both engineers and architects! Col. Roebling, however, did not live to see the completion of this great work. While personally laying out the towers, he received injuries which caused his death in July, 1867. The work was completed by his gifted son, Col. Washington Roebling. This noble structure has a main span of 1595 feet 6 inches, and a clear height above the water of 135 feet, allowing ocean-going vessels to pass underneath. Its decks accommodate two ele- vated railway tracks, two surface traction tracks, two roadways and one walkway. The cost was about sixteen million dollars. (Plate CXIV.) New York—Williamsburg and Manhattan Bridges Since the building of the Brooklyn Bridge, two other suspension bridges have been built over the East River at New York, known as the Williamsburg Bridge, completed in 1903, and the Manhattan Bridge, completed in 1909. The former has very little to commend from an architectural viewpoint. The staunch stone towers of the Brooklyn Bridge are paralleled by awkward-looking towers of steel. In the design of the Manhattan Bridge, however, we witness a return to pleasing proportions, made possible by a radical change in the principles of construction, consisting in se- curing the cables at the tops of the towers, thus doing away with the clumsy saddles, and hinging the tower itself at its base to allow it to rock to and fro with the variations in length and sag of the cables. This change permitted the use of a comparatively slender tower of steel of pleasing form and proportion. No consulting architect was employed on the general design of the Williamsburg Bridge. The Manhattan Bridge has a span of 1470 feet, while the span of the Williamsburg Bridge is 1600 feet, exceeded only by the Philadelphia-Camden Bridge recently com- pleted. Carere and Hastings were consulting architects on the Manhattan Bridge, collab- orating with the engineers of the Department of Plant and Structures of the City of New York. (Plates CXV & GXVI.) Engineering of New York Bridges* The construction of the great East River Bridges at New York was made possible by the development of modern methods and materials of engineering. Perhaps the most important development was that of the pneu- matic caisson, by means of which foundations *Physical data regarding New York East River Bridges: Brooklyn Bridge: Length over all, 7811 ft. 6 in. River span, 1595 ft. 6 in. Height of towers, 272 ft. Cables, 1524 in. diam- eter. Weight of metal, 21,920 tons. Masonry in piers, 85,160 cu. yds. Capacity, two elevated railway tracks, two surface railway tracks, two roadways, 16 ft. 9 in. wide, and one foot- walk 15 ft. 7 in. wide. Williamsburg Bridge: Length over all, 8908 ft. River span, 1600 ft. Height of towers, 333 ft. Diameter of cables, 18.625 in. Weight of metal, 45,285 tons. Masonry, 158,300 cu. yds. Total cost, $14,181,560.00. Capacity, six tracks, two road- ways, 19 ft. 11 in. each, and two foot walks, 17 ft. 8 in. Manhattan Bridge: Length over all, 8325 ft. Length of river span, 1470 ft. Height of towers, 322 ft. 6 in. Diameter of cables, 2114 in. Weight of metal, 59,450 tons. Masonry, 308,000 cu. yds. total. Capacity, eight tracks, one roadway, 35 ft. wide, two walks, 13 ft. 7 in. wide. Cost $14,000,000.00. Queensboro Bridge: Length over all, 7450 ft. Longest spans, 1182 ft. Height, 323 ft. Weight of steel, 73,800 tons. Masonry, 106,000 cu. yds. Cost, $13,500,000.00. Completed in 1909. [178.1 BRIDGE ARCHITECTURE in water could be carried to much greater depths than was before possible. The pneumatic caisson is an adaptation of the diving bell, consisting of a chamber open at the bottom only, and supplied with com- pressed air, the pressure being varied to com- pensate the exterior water pressure. Workmen operating in compressed air (called sand-hogs) can work only in short shifts. The pneumatic caisson was used in the construction of the Forth Bridge in Scotland, the Eads Bridge at St. Louis, which was its first notable application in America, and for all of the East River Bridges. Another important factor was the improve- ment of steel wire, making available strands of much stronger material than it had here- tofore been possible to obtain, and allowing the construction of suspension bridges of larger span. Coincident with these developments was a much more accurate knowledge, on the part of engineers, of the properties of materials, and of the stresses and strains involved in bridge structures, a knowledge that came from the establishment of engineering colleges and from testing laboratories. Philadelphia-Camden Bridge The Philadelphia-Gamden Suspension Bridge,* the largest and newest of the type, was completed in 1926 after more than a hun- *Physical data regarding Philadelphia-Camden Bridge: Total length, including approaches, 9570 ft. Length of main span, 1750 ft. Width of bridge, 128 ft. Width of road- way, 57 ft. Height of towers above water, 380 ft. Clearance of bridge above mean high water, 135 ft. Deepest foundation below mean high water, 105 ft. Diameter of cables, 30 in. Total length of wire used, 25,100 miles. Granite masonry, 25,200 cu. yds. Concrete masonry, 289,800 cu. yds. Struc- tural steel, 61,700 tons. dred years’ agitation for a bridge at this site, at a cost of about twenty-five million dollars, exclusive of real estate. It is the only bridge crossing the Delaware River at Philadelphia. The engineers in charge were Ralph Modjeski, George S. Webster and Lawrence A. Ball, with Paul E. Cret as architect and Clement E. Chase as resident engineer. This huge struc- ture carries a 57-foot wide roadway, four railway tracks and two footwalks. (Plates CXVII & CXVIII.) Two charming suspension bridges have recently been built which illustrate clearly the architectural advantages inherent in this type. These are the new bridge over the Rhine at Cologne, completed in 1915, and the Seventh Street Bridge at Pittsburgh over the Allegheny River, completed in 1926. These two structures are quite similar in design. The Cologne bridge has a center span of 184.4 meters, flanked by two side spans of 92.2 meters each. (Plate CXIx). Pittsburgh—Seventh Avenue Bridge The bridge over the Allegheny River on Seventh Avenue, Pittsburgh, a beautiful struc- ture, recently completed, is but one of many bridges planned to cross the Allegheny and Monongahela Rivers at Pittsburgh. They will replace older structures that fail to meet navigation requirements. This structure is of the self-anchored suspension type. The main span is about 442 feet long and the side spans 221 feet long, while the roadway is 3714 feet wide between curbs, with a sidewalk on each side. The similarity of this design to that em- ployed for the new suspension bridge across [ 174 ] BRIDGE ARCHITECTURE the Rhine at Cologne, and, with the excep- tion of the use of metal towers instead of masonry, to those at Budapest, is notable. These Pittsburgh bridges are being construct- ed by Allegheny County, of which V. R. Covell is chief engineer of bridges, and the program comprises some forty-three bridges to be constructed during a period of ten years, and entailing an expenditure of about $23,000,000. (Plate cxx.) The peculiar charm of the suspension bridge is due largely to the fact that the system of Stresses and strains involved is the most simple possible, and every main member of the structure expresses strongly the part that it plays in the system. iva ARCHITECTURE BRIDGE N SO ~~ \N NS , vy _ °OD ONIMSI1GNd LIOULAG AHL XA GALHOLAAdOD OLOHA YHCTINA “NOLATMNAL NHOf—018I—aDdIud NOISNAdSNS NIVHD A'TO—'SSVIW ‘LHOdAMNAMAN—XD ALVId 176 BRIDGE ARCHITECTURE 9681 HOC NOISNAdSNS S.GHOATHLI—SATVM “SLIVULS IVNAW—IXO HLVId ea | [ BRIDGE-ARCHITECTURE re ah} CURE corn BB a: 7% “Sree. TEU YT T PLATE CXII—BUDAPEST, HUNGARY—KETTENBRUCKE—1849—W. T. TIERNEY CLARKE, ENGINEER PHOTO BY ERDELYI, BUDAPEST BRIDGE ARCHITECTURE Lsadvand BeGicCatrict Ad OLOHd S061 GHLH Id NOD LOALIHOYYV ‘ROWN WW CHAANTDNG ‘SOITHHDAZD “V—aDCIYd HLAAVZITA—AYVONNH “LSHdVONd TIX) BLY Id | J eS SUM SVAN = a9 [ BRIDGE ARCHITECTURE 390189 NATHOON © WYOX MAN ‘SHUNLONULS GNV LNVId dO INIWLIMVdad WOud OLOHA YAANIONA “ONITAXOU “V NHOL "1OO—e88I—ADGIUd NATMOOUM—WUOA MAN—AIXD WLW Id [ 180 ] BRIDGE ARCHITECTURE YHATY LSVA HHL YHAO Hoda DYOASNVITTIIM—WYOA MHN—AXD HLVITd Ye [181 ] BRIDGE, ARCHITEC TURE SLOULIHOYUVY DNILTASNOD ‘SONILLSVH ¥ AYAYYVO “SHHANIONA “MHOA MAN AO ALIO AHL JO SHYALOOULS P LNVTd tO LNANLYVddd—606l—YoATY LSVA AHL YHHAO ADCGIYA NVLLVHNVN—YYOA MAN—IAXO ALVWId Ss ee pan ot reralaieampr emt MTS pepe, rc ANIA ® [ 182 ] BRIDGE ARCHITECTURE LOALIHDYY “LAYD “A TOVd YAANIONGA AAIHOD ‘IMSHGOW Hd TVe—926I—YH ATH AYVMVTAC AHL WAAO AOCTHE NAGWVO-VIHd THQVTIHd—HAX) ALV Id aoe eee ae Saft 1S TCR SVST IVA {SIERO Sh ee BE a i io ete [ 183 ] BRIDGE ARCHITECTURE Te To ri el PLATE CXVITI—PHILADELPHIA-CAMDEN BRIDGE—DETAIL OF ANCHOR PIER—1926 RALPH MODJESKI, CHIEF ENGINEER; PAUL E. CRET, ARCHITECT [ 184 ] BRIDGE ARCHITECTURE YWHANIONG ‘ZLAIG “M—Sl6I—ANIHY AHL YHAO ADGLIYA NOISNAdSIS—~ANVINYAD ae ‘ANDOTOD XIXO ALVTd 185 BRIDGE: ARCHITECTURE PLATE CXX—PITTSBURGH, PA.—SEVENTH AVENUE BRIDGE OVER ALLEGHENY RIVER—MAIN SPAN 442 FEET—1926 V. R. COVELL, CHIEF ENGINEER [ 186 ] ea e - ies a ee ee se ee om ——— =. | EE MODERN CANTILEVER BRIDGES | ae only competitor, from an engineering standpoint, of the suspension type of bridge when used for long spans, is the canti- lever type, and this is generally conceded to excel all other types in its innate ugliness. Its complicated system of trussing is utterly unin- telligible to the layman, and being unintel- ligible, is necessarily offensive. Even when of great and noble proportions, as the huge Forth Bridge in Scotland, or the Quebec Bridge in Canada, or the Queensboro Bridge in New York, it cannot give to the eye that pleasure which is furnished by the arch and the suspension types. On the other hand, the cantilever type furnishes a more rigid struc- ture than the suspension type and so is better adapted to carry heavy, concentrated loads. Although these great cantilever bridges are all of recent construction, the cantilever type is not recent, as the principle has been used since the earliest times. These early bridges, however, are primitive and almost invariably make use of a series of cantilevered beams such as shown by the picture of an old bridge at Bhutan in Thibet, consisting of cantilevered wooden beams, weighted down at the shore or pier end by stone masonry. (Plate II.) One of the most important structures of this type in America is the Queensboro Bridge over the East River at New York, completed in 1909, formerly known as the Blackwells Island Bridge. (See page 174 for physical data.) The Queensboro Bridge was designed by the engineers of the Department of Plant and Structures, with Henry F. Hornbostel as con- sulting architect. (Plate CXXT.) Bridge over the Firth of Forth Of all the great cantilever bridges, this bridge is doubtless the most famous. It is the work of Sir John Fowler and Sir Benjamin Baker and consists of three huge cantilevers, 1700 feet span and 336 feet in height. The lower chords of the cantilevers are curved and brought close to the water at the springing line, and this fact, together with the compara- tively short length of the suspended span, 350 feet, gives the general effect of two huge arches and two half arches. The simplicity of the truss system, obtained by the use of as few members as practicable, and those of large size, also contributes to the peculiar appeal of this structure. Unfortu- nately, engineers are agreed that this does not result in the maximum economy of material and the old question then arises—Is it allow- able for the engineer to depart from the re- quirements of absolute economy in the design of a bridge, and adopt a more pleasing out- line at somewhat greater cost? The right and duty of an architect so to do in the case of a monumental building is not questioned. Why should not the engineer be allowed the same privilege, or rather, be taught the same duty? This bridge carries a double track railway and was completed in 1883. (Plate CXXIT.) A design of cantilever bridge extensively used consists of one or more simple truss spans [ 187 ] BRIDGE having the ends cantilevered out beyond the piers and supporting shorter and shallower suspended spans. Typical of this type is the bridge over the Hudson River at Poughkeep- sie, New York, the Queensboro Bridge over the East River at New York and the bridge over the Mississippi River at Thebes, Illinois. rikigiy Me One of the most famous bridges in the world, and holding the record clear span of 1800 feet, is the Quebec Bridge over the St. Law- rence River, located about nine miles above Quebec, Canada, where the river is compara- tively narrow, but more than 200 feet deep. This great structure carries two railroad tracks over the river at a clearance for boats of 150 feet and was completed in 1912 after the failure of one structure, which collapsed dur- ing erection. This accident occurred on August 29, 1907, causing the loss of seventy-four work- men. The ancient saying that “the bridge de- mandsa life’ was more than exemplified in this structure, which demanded many. The design of the structure as finally built was made by Phelps Johnson and G. H. Duggan, of the St. Lawrence Bridge Company, acting with an ad- visory board of five engineers, of which Ralph Modjeski was chairman. (Plate XXIII.) (0 See The bridge at Thebes, Illinois, built in 1905, after designs by Alfred Noble and Ralph Modjeski, both eminent American engineers, has a length of 2597 feet over all, and com- prises one span of about 790 feet and two of 621 feet. The trusses are so nearly uniform in depth that they give the appearance of continuous trusses, a type of bridge not much different in appearance. (Plate CXxry.) ARCHITECTURE Simple Steel Trusses and Girders The homely and economical simple truss and girder bridges, built by the hundreds to carry the railroads which have covered the face of the land with a network of iron paths during the past century, over river and valley obstructing their way, have too often been the subject of unmerited abuse. Ugly most of them are, without question, and yet not all. Some are beautiful in their simple lines, and others have a distinct charm, especially when combined with masonry abutments and piers of good outline and proportion. The European truss bridge is usually of the so-called multiple intersection type, as con- trasted to the typical American practice of single members, forming triangles and as few in number as practicable. Doubtless the mul- tiple system is more pleasing to the eye: it is more complete and more logical to the un- technical mind. As typical examples of good American and European practice in the design of bridges of simple trusses and girders, the following structures have been selected for illustration: Railroad Bridge over Street, London. (Plate Cxxv.) Bridge over the Hudson at Castleton, N. Y. (Plate CXXvVI.) Bridge over the Susquehanna River at Havre de Grace, Maryland. (Plate CXXvVII.) Bridge over the Rhine at Mayence, Ger- many. (Plate CXXVIII.) Steel Railway Bridge over the Rhine at Cologne, Germany. (Plate GXXIX.) Steel girder Railway Bridge at Cleveland, Ohio. (Plate CXXX1.) [ 188 ] BRIDGE ARCHITECTURE [ 189 | PLATE CXXI—NEW YORK—QUEENSBORO BRIDGE OVER THE EAST RIVER—1909—DESIGNED BY THE DEPARTMENT OF PLANT & STRUCTURES, CITY OF NEW YORK—HENRY F. HORNBOSTEL, CONSULTING ARCHITECT BRIDGE ARGHITE GPG Ran SYUAANIONA ‘WHMVE SOIAUAS OLOHd SUAHSITANd AHL AP LHDIMAGOD OLOHA {NAG YIS GNV YATMOd NHOL HIS—¢s8I—aDGIMd HLYOd AHL—ANWTLLOOS~-HXXO ALVITd a Y RXX YY Yr ‘4a, a re : o% ALEX YY) j 190 | | BRIDGE ARCHITECTURE YHUNIDNA AMIHD TMSHfCOW Hd TVU—L16I—ADNAYMVT OLS AHL YAAO ADGIMA—VGVNVD ‘OHMANO—-INXXD ALWId 191 [ BRIDGE ARCHITECTURE ODVOIHD ‘AILSIMO Ad OLOHd SHUAUNIONGA ‘THSALCOW Hd TV (NV HTIPON GCHYATY—S06l GHLATMINOO—YAATY IddISSISSIN AHL YWAAO AOCGIYG— TI ‘SHAHHL—AIXXD ALVId { 192 ] BRIDGE ARCHITECTURE PLATE CXXV—LONDON—RAILROAD BRIDGE OVER STREET—ST. PAUL’S IN BACKGROUND PHOTO FROM GENERAL PHOTOGRAPHIC AGENCY, LONDON [ 193 | BRIDGE ARCHITECTURE ‘AN ‘ANV@‘IV ‘LLDILYVa “9D “H WOU OLOHd 9c6I—"H “HO CA CN ‘UAHNIONGA ADCIUE ‘ALTUM ‘L “H YAATY NOSCGNH AHL YHAO “YY TVULNAD WHOA MAN DONIAYHVOD ADCIYA—'A “N ‘NOLATLSVO—IAXX9D ALVId [ 194 ] BRIDGE ARCHITECTURE ) PLATE CXXVII—HAVRE DE GRACE, MD.—BALTIMORE & OHIO R. R. BRIDGE OVER SUSQUEHANNA RIVER [195 | BRIDGE ARCHITECTURE ANIHY AHL YHAO HOGIYA MAN AHL—ANVNYHD “AONAAVN—ITAXXD ALWId [ 196 ] BRIDGE ARCHITECTURE AMVUCG Ad ‘Il WVITIIM AO GNV “UHSVId AD ‘AL WVITIIM JO ANLVLIS—6S8I—ANIHY AHL YAAO AOCGINA AVM TIVU—ANVINYAD “ANDOTOD—XIXXO ALVTd ARGHITECTURE BRIDGE ANIHY AHL YAAO AOGCIYA—ANVNYAD ‘ZNATHOO—XXKXD ALVId 198 ] [ BRIDGE ARCHITECTURE Te i en YAHANTONA “NOSLYM ° 816l LIWOd— , oa? LAAULS HLO¢ LSVA HAAO ADGIMG GVOUWTIVY—OIHO ‘GNVIAAATTIO—IXXX) ALVTd AL albl aaS errr vem tees vi , 4 eR sets saint HUQTAAEONUAUGA GHbadiNdii aiaatinnittitiil VMUVEUUHEEGRELENUGEUULE ULE MPPPTTTTe seeMeuUNNE le Fa A aut EONUOUEOEECUUNOTUNOAT Pre ~ (eee a et a es A I ae SS 199 MODERN CONCRETE BRIDGES HE invention of reinforced concrete has placed in the hands of modern bridge en- gineers a new material in which to work, a material that, to many intents and purposes, is stone masonry, but stone masonry that has the property of offering great resistance to tensile stresses, by virtue of the steel embedded within, which is protected by the surrounding concrete from corrosion. Furthermore, this material is plastic and can be cast into any desired form, at less ex- pense than similar forms can be cut out of the natural stone. It is evident, therefore, that the new material offers to the bridge engineer and to the architect collaborating in bridge de- sign, a great opportunity. That the engineers and architects have not been oblivious to the opportunity is evidenced by many beautiful structures built of this material in the last two decades, especially those located in the United States, which are, as a rule, more pleasing than the much lighter and appar- ently attenuated forms generally used abroad. It was only two decades ago that the chief engineer of one of the greatest American rail- road systems was quoted as saying that con- crete would not be used by that company, because he did not believe, and no one could make him believe, that man could make as good a building stone as that made by the Creator. But concrete is now a standard building material of that great railroad sys- tem as of most others in the construction of bridges for which cut stone was formerly used. Unquestionably, concrete constructions do not possess the same charm as well designed and executed cut stone masonry, a truth that is explained by one writer as due to the pres- ence of the tool marks of the craftsman in the case of cut stone structures and its absence in concrete. The tool marks express to the obk- server the human labor required to create the object, and give it a human interest. The greatest architectural defect of con- crete, however, is doubtless the lack of color effect in its finished surfaces, and especially the lack of color variety. The uniformity of color and texture of concrete surfaces is mo- notonous and displeasing. This loss of the charm of the natural stone wall, however, is balanced by the economy of the material, allowing its use in many places, especially for small bridges, where natural stone could not be used or afforded and where cheap, unsightly steel trusses would formerly have been built. In all fairness it should be stated, however, that the ugliness of the small steel bridge is due, not to any inherent defect of the ma- terial, but to the utter lack of any attention to considerations of beauty on the part of designers, such lack being caused by the former commercialization of the art, practically all designs for small structures, and many for large ones, being made by the fabricating companies, under competitive conditions that [ 200 | BRIDGE ARCHITECTURE precluded any consideration of art or taste. Such a system, while possibly resulting in the greatest economy of first cost, is essentially bad, because it results not only in the total elimination of artistic considerations, but also results in the production of structures that are weak and short-lived, and more ex- pensive in the long run than would be the case if better designs were adopted at perhaps somewhat greater first cost. Furthermore, a beautiful and pleasingly designed bridge has a certain value to a com- munity not easily expressed in dollars, but which pays dividends in pride in one’s com- munity, a pride which contributes to human happiness and contentment. Quoting the editor of “The Builder” (Aug. 27, 1926), “The Engineer’s artistic failures occur when he has not interested himself in the appearance of his building and allows himself to be governed blindly by economy.” In studying these illustrations of concrete bridges, it will be seen that, in order to obtain the most pleasing results, concrete must be treated as a different material than natural stone and that the obvious forms of cut stone masonry should not be imitated in using the plastic material. The earlier examples com- mitted this error extensively, but later designs are better. One of the first large concrete bridges to be built in this country is The Connecticut Ave- nue Bridge at Washington, D. C., completed in 1904, after designs by George 5. Morison, noted American bridge engineer and designer of many railroad bridges; and built under the direction of W. J. Douglas, engineer, and E. P. Casey, architect. This bridge is 1341 feet long, 120 feet high and 52 feet wide. It contains seven semi-circular arches, five of which have a span of 150 feet. These arches carry six small spandrel arches, also semi- circular. The parapet is composed of concrete posts with a bronze railing. The material of which the concrete of this imposing work is made is crushed granite, and exposed surfaces were carefully tooled when cured, exposing the aggregates of the concrete. The quoins of the piers were made of precast blocks of con- crete. Considered either from the viewpoint of the engineer or the architect, this work must be conceded to be one of the finest, if not the best executed concrete bridge yet built. After twenty-two years of service, it exhibits no defects or deterioration. (Plates CXXXII & CXXXIIL) The Walnut Lane Bridge in Fairmount Park, Philadelphia, completed in 1908 after designs by H. H. Quimby, has a main span of 233 feet, a height of 147 feet and width of 60 feet. Its setting, being located over a parkway, adds greatly to its beauty. (Plate CXXXIV.) The Bridge over Rocky River, near Cleveland, Ohio, completed in 1910 after designs by A. M. Felgate, is quite similar in conception to the Walnut Lane Bridge, but more massive in design and of longer span. At the time of its construction, this bridge held the record for length of span for a masonry arch bridge, a record since broken by several structures. The main arch span is 280 feet opening and comprises two massive ribs, not reinforced. [201 | BRIDGE ARCHITECTURE The length over all is 708 feet and the width 60 feet. The massiveness of these arch rings is in harmony with the span and heavy super- structure, a feature lacking in so many rein- forced concrete arch bridges, the designers of which seem to attempt the greatest possible attenuity of the arch rib. In the construction of this bridge, a facing mixture composed of specially selected aggregate (crushed granite) was used for all exposed surfaces. (Plate CXXXV.) The Cherry Street Bridge over the Maumee River, at Toledo, Ohio, completed in 1912 after plans originally drawn by The Osborn Engineering Co., of Cleveland, and later modi- fied and executed by Ralph Modjeski, has a length of 1217 feet and width of 80 feet and comprises ten arches, elliptical in shape, and having maximum spans of 108 feet at the center, diminishing in length toward the ends. At the center is a bascule span providing 200 feet clear opening for the passage of boats, and carried on two massive abutment piers. These center piers have octagonal ends, which were intended to carry ornamental towers de- signed by the late Arnold W. Brunner, but not built owing to lack of funds, an omission which ruins the appearance of so many of our. monumental structures. The excuse is always made that these ornamental features are not strictly necessary, which, of course, has to be admitted if it be admitted that beauty of form is not a necessity to civilized man. The Cherry Street Bridge is described in the Transactions of the American Society of Civil Engineers, 1915. (Plates GXXxxvI & CXXXVII.) The King Avenue Bridge over the Olentangy River, at Columbus, Ohio, built in 1912 and 1913 from designs by W. J. Watson and Walter Braun, comprises four elliptical arch spans of the solid spandrel type. The arches a ey AO ceil nt 9 <8 CHERRY STREET BRIDGE, TOLEDO, O. COLUMN DESIGN BY ARNOLD W. BRUNNER have a clear opening of 85 feet each. The length over all is 429 feet 9 inches and the width 47 feet. This bridge may be considered as typical of its kind, although greater pains have been taken to obtain pleasing lines than is usual [ 202 ] BRIDGE ARCHITECTURE in this class of structure. The essential features may be described as the use of perfect ellipses for the intradosal curves, curved cutwaters for the piers, curved retaining walls at the abutments and a carefully executed parapet. Another feature of this bridge is the light color, almost white, obtained by the use of selected aggregates (white limestone) for the concrete. No attempt to imitate cut stone masonry is made. Some details of the King Avenue Bridge at Columbus, Ohio, illustrate methods of treat- ing cutwaters and piers. The slight projection of the pilasters, only a few inches, is just enough to provide a line for the necessary expansion joints. The treatment of the wing walls at the abutments, which are curved instead of straight, is a detail not expensive to carry out in concrete. (Plate CXXXIX.) A concrete Viaduct at Willoughby, Ohio, car- ries the Buffalo-Cleveland Road, a heavily traveled highway, over the valley of the Chagrin River, on a bridge 1080 feet long, containing nine arch spans of 100 feet each and two 50 feet each. The parapets and lamp t, al br PK a KING AVENUE BRIDGE, COLUMBUS, O.—DETAIL KING AVENUE BRIDGE, COLUMBUS, O.—DETAIL standards are of cast concrete, using red granite aggregates, the surface being scrubbed while the concrete was green in order to expose the granite. This bridge was completed in 1921, after designs by W. J. Watson and W. P. Brown, with M. P. Potter as collabor- ating architect. (Plates CXLII & CXLIII.) uw 7 cf A concrete bridge of the New York Central Railroad at Willoughby is a good example [ 203 | BRIDGE ARCHITECTURE THIRD AVENUE BRIDGE, COLUMBUS, 0,—DETAIL of the massive type of concrete arch of the ribbed type, as adapted to heavy railroad work. This bridge was designed by Samuel Rockwell, chief engineer, and O. W. Irwin, assistant. (Plate GXLIV.) Richmond, Virginia, has a_ historic bridge over the James River known as the Mayo’s Bridge, a bridge bearing this name having existed at this site from early colonial times. In 1911, it was decided to replace the old structure, which was too light for the in- creasingly heavy traffic, with a new and modern concrete structure, and a board of three engineers, consisting of the late Col. - C. P. E. Burgwyn, Chas. E. Bolling and W. J. Watson, was appointed to report upon plans. Competitive plans were received and the de- sign submitted by The Concrete Steel Engi- neering Company of New York was selected. This bridge is 1775 feet long over all, and contains eighteen arches, having a clear span of 71 feet and a rise of only 7 feet. The project was completed in 1914. In no way does the design of this structure involve concrete in imitation of cut stone masonry forms. (Plates IXLV & CXLVI.) > Y of At Akron, Ohio, there stands a reinforced concrete highway bridge over the Cuyahoga River Gorge, which is one of the highest structures of this kind in the world, its deck being 192 feet above the water. On account of its great height and park-like setting, in a deep wooded ravine, this bridge presents a striking profile. Its length is 781 feet 9 inches over all and it comprises five semi-circular arches, each 127 feet in length from center to center of high, hollow piers. The engineer was W. J. Watson. This bridge was built in 1915. (Plate cXLvII.) y uf t, The concrete viaduct carrying the Cumberland Valley R. R. over the Susquehanna River at Harrisburg, Pa., was built in 1915-16, from designs by the Railroad Company’s engineers. This massive bridge is 4000 feet long and comprises 45 spans of about 76 feet each. RAILING AND POST OF WILLOUGHBY BRIDGE [ 204 ] BRIDGE ARCHITECTURE The work was carried out in two longitudinal halves, traffic on the railroad not being inter- rupted by the construction. (Plate CXLVIII.) On the Florida East Coast Railway, between Miami and Key West, a very long concrete bridge connecting two keys, famous as the Long Key Viaduct, was completed in 1907. The design is not unusual and is devoid of architectural treatment, but its great length of two miles and the boldness of the under- taking, the site being in the open sea, are noteworthy, and have caused it to be classed as a wonderful engineering accomplishment. At Dayton, Ohio, a number of imposing bridges of reinforced concrete cross the Miami and Mad Rivers, some of which were built before the great flood of 1913, that destroyed a large part of the city, and were but little damaged thereby. A recent structure by Chamberlain & Smith, architects, of Dayton, is unique in design. (Plate CXLIX.) The longest concrete bridge yet built in a single span was recently completed over the River Seine, below Paris, boasting the un- precedented span of 450 feet. It possesses little architectural merit, and it is somewhat puzzling to one that the French engineers and architects, who have built the most beautiful stone bridges in the world, seem to make so little effort to obtain equally pleasing designs in concrete. (Plate CL.) The Tunkhannock Viaduct, on the D., L. & W.R. R., is the most stupendous achievement in concrete bridge construction yet attempted. This great structure is 2375 feet in length, and 240 feet in height above the ground, while its foundations extend another 60 feet below the ground surface, a total height of 300 feet, easily the world’s record for this kind of a bridge. The design is by George J. Ray, chief engineer, D., L. & W. R. R., and the work was carried out by Flickwir & Bush, contractors, and completed in 1916. About 162,000 cubic yards of concrete were used in its construction. (Plate CLI.) The division of the arch ring into imitation voussoirs is especially to be criticised in this case, as the proportions of the arch rings make them obviously false. Would not the piers look better if the jointing also had been omitted, or so designed as not to simulate cut stone forms? Another detail used in the design of the Tunkhannock Viaduct and in many other recent bridges, which is evidently superfluous and therefore questionable, is the use of the projecting cap at the top of the spandrel posts. In most cases, the design would actually be much improved by the omission of this ex- pensive detail. This statement is well illus- trated by a comparison of this detail of the Tunkhannock Bridge with that used on the Connecticut Avenue Bridge at Washington. The D., L. & W. R. R. has built many very beautiful concrete bridges in recent years, that over the Delaware River just below the Dela- ware Water Gap being perhaps the most striking. This bridge has a length of 1450 feet and is composed of a series of 150-foot spans of the open spandrel type. It was completed in 1910. Lincoln Bush and George J. Ray were the engineers in charge. (Plate CLIT.) [ 205 | BRIDGE ARCHITECTURE The Washington Street Memorial Bridge at Wilmington, Delaware, is a fine example of the modern concrete highway bridge, one of the best yet executed. The design is by B. H. Davis, engineer, in collaboration with V. W. Torbert, architect. This bridge comprises a single arch span, of the ribbed, open spandrel type, flanked on each side by two arches of the solid spandrel type. At each end of the main span are massive pylons supporting memorial tablets, and smaller pylons are placed at the ends of the bridge. (Plates CLIII, CLIV & CLV.) It has been suggested that the arch ring and the piers also of a concrete bridge should be divided to indicate just how the sections were placed. The charm of stone masonry is largely due to the fact that the jointing expresses the manner in which the work is done. False joints in stone masonry, therefore, are generally avoided. Should not this principle be applied to concrete masonry? Stone masonry is laid up of separate blocks, while concrete is a plastic material and should not imitate the structural forms and details of stone block masonry which are required by the nature of the material, but are not re- quired by concrete. Authorities on architect- ural history tell us that the dentils used in classical structures are probably imitations, in stone, of the ends of timber rafters used in still more ancient structures. Dentils, how- ever, when used as corbels, serve a useful purpose in supporting an overhanging cornice or coping, and they have been extensively so used in bridges in the past, and quite effec- tively. When the dentil is introduced into concrete masonry, however, it does not seem to express this function as well as it did in stone masonry. In concrete designs it is seldom used as a structural member, its function becoming evidently purely decorative. Concrete is essentially monolithic, and de- signs executed in concrete should, properly it would seem, express this fact, not conceal it, and this expression can be conveyed by the use of plastic forms, mouldings and curved surfaces. In spite of much that has been quoted herein about unnecessary decoration as applied to bridges, a certain amount of plastic decorative design helps to express to the observer the nature of the material. Proper treatment of the surface is also needed to express the nature of concrete. In Stone masonry this is accomplished by the tooling necessary to prepare the blocks for use. In the case of concrete, which is composed of cement and small pieces of stone, if it is desired to show these elements, surface treat- ment is required, which is not a constructive necessity, but purely a finishing operation. The Dumbarton Bridge, on Q Street, Wash- ington, D. C., a very unique structure, carries Q Street over Rock Creek Park on a curve. The spandrels are tooled to give a coarse texture to the concrete. The arches are semi- circular in shape, being outlined with a nar- row ring of smooth finished concrete. The end posts are surmounted by heavy cast bronze buffaloes designed by A. Phimister Proctor, sculptor. The architect was Glenn Brown. (Plate CLVI.) 7 xy 7 The new bridge over the Monongahela River [ 206 ] BRIDGE ARCHITECTURE at Fairmont, West Virginia, claims especial merit in the treatment of the railing, the combined trolley and lighting poles and the overhanging recesses. The design is by The Concrete-Steel Engineering Company of New York, William Meuser, engineer. (Plate CLVIH.) A bridge at San Diego, California, called the Cabrillo Bridge, consists of a series of severely plain concrete arches and formed one of the principal approaches to the Panama-Califor- nia Exposition held in 1915. This bridge was greatly admired by visitors to the Exposition. Itis utterly devoid of any attempt at ornamen- tation and practically without detail, yet beautiful in its simplicity. It is composed of seven semicircular arch spans of 56 feet open- ing each, and has a total length of 946 feet. The designer is Frank P. Allen, Jr., in col- laboration with Cram, Goodhue & Ferguson, architects. (Plate CLVIHL.) The Cappelen Bridge over the Mississippi River at Minneapolis, Minn., contains the longest reinforced concrete arch yet construct- ed in America, 400 feet in length. This bridge is named for the late F. W. Cappelen, City Engineer of Minneapolis, and is 1100 feet long, comprising one span of 400 feet, two of 199 feet, and two of 55 feet opening, carrying a 40-foot roadway and two 8-foot walks. (Plate CLIX.) At St. Paul, Minnesota, Messrs. Toltz, King and Day, architects and engineers of that city, have built a reinforced concrete bridge over the Mississippi River, known as the Robert Street Bridge, which comprises a clear span of 244 feet in its total length of 1900 feet and presents some unusual archi- tectural details. (Plate CLX.) Pont Butin at Geneva, Switzerland A bridge has recently been completed at Geneva, Switzerland, which illustrates the modern tendency among European engineers and architects toward the use of concrete and stone masonry in combination, the former as a strictly structural material, and the latter for facing purposes. This bridge is known as the Pont Butin, and spans the River Rhone. Its length over all is 276 meters, comprising five semicircular arches with clear spans of 48 meters. These five arches carry the railway tracks and a series of twenty-five smaller arches which form the upper deck, used for a highway 15 meters wide. The height is 52 meters. The entire structure is of rein- forced concrete with a facing of limestone and granite. The engineers in charge were M. M. Bollinger and Company of Zurich, and the architect collaborating was M. Garcin, of Geneva. (Plate CLXII.) Other modern European masonry bridges, constructed partly or wholly of concrete, and worthy of study, are the Pont de Malling, a railway bridge in Lorraine, and two bridges at Rome, known as the Ponte Cavour and the Ponte Umberto. (Plates CLXIII, CLXIV & CLXV.) Zaionte A bridge of unique design was built by the Westchester County Park Commission in 1915, at Scarsdale, New York, from plans by Delano and Aldrich, architects, in collabora- tion with the engineers of the Commission, [ 207 ] BRIDGE ARCHITECTURE of which J. Downer is chief engineer. This bridge is on a curve and the spans are supported on circular piers placed on the center line of the roadway. (Plate CLXVI.) So few American bridges have the charm of old historical interest or of ancient folklore that attaches to many bridges in Europe, that advantage should be taken of every oppor- tunity to lend interest to the more important structures by naming them in commemora- tion of historic events that took place in the locality, or by the name of the community which they serve, or occasionally, the name of a noted architect or engineer. The Key Bridge at Washington, recently completed, crosses the Potomac River near the site of the home of Francis Scott Key, the composer of “The Star Spangled Banner’; the proposed Arlington Bridge will form the principal approach from the City to Arlington National Cemetery; the Cappelen Bridge at Minneapolis (already described) was so named in honor of a city engineer who served the municipality faithfully for many years and well merited the recognition. The Cali- fornia State Highway Commission has named one of its most beautiful structures after the late Harlan D. Miller, for many years its bridge engineer. How much such a plan adds. to the human interest of a bridge. (Plates CLXVII, CLXVITI, CLXIX & GEXK) The ordinary railroad bridge is seldom in- teresting from any standpoint except that of strict utility, safety and economy, yet quite often this type of structure may be greatly improved, architecturally, without increase of cost. This was the case with the two crossings of streets by the tracks of the Cleveland & Youngstown R. R., and the New York Cen- tral R. R. in Cleveland, shown by plates. The tracks are carried over the streets by massive concrete arches, designed for the heaviest modern loading, with no attempt whatever at ornamentation, such interest as they have being due entirely to their mass and propor- tion. These structures cost no more than much less attractive bridges of steel would have cost, although very pleasing results can be obtained, if desired, with the latter material. Unfortunately, in so many cases, the desire to make such structures good-looking does not exist, either in the minds of the owners or of the designers, or, if it does exist, is immediately dismissed with the idea that anything that is good-looking is necessarily more expensive and extravagant or wasteful. (Plates CLXXI, CLXXII, CLXXIII & CLXXIV.) . 7 7 Good architecture in bridges is not and should not be confined to the larger projects, but is of equal importance to the small structure. As examples of what may be RAILING DESIGN BY Cc. A. P. TURNER [ 208 ] BRIDGE ARCHITECTURE accomplished in the design and construction of small highway bridges in concrete, note the illustrations of such structures at Niagara Falls, Ontario; Lynchburg, Virginia; Mont- clair, New Jersey; at Piedmont and at River- side, California; at Cincinnati, Ohio; at Jack- sonville, Florida; Gaston County, North Car- olina, etc. All of these are small, inexpensive structures. (Plates CLXXV, CLXXVI, CLXXVII, Oiercvitl CLXXIX, CLXXX, GLXXXI, CLXXXI; CUAXKXIM, CLXXXIV, CLXXXV, CLXXXVI, CUAXX VII, CLXXXVIII.) Some Proposed Bridges Studies are now being made looking to the construction of the most stupendous bridge ever built—that over the Hudson River at Fort Lee, New Jersey. A tentative report has . already been made by a commission of the Port of New York Authority, composed of O. H. Ammann, W. W. Drinker, Prof. W. H. Burr, engineers, and Cass Gilbert, architect. This tentative report contemplates the con- struction of a suspension bridge comprising a central span of 3500 feet, twice that of the Philadelphia-Camden Bridge, the longest yet built. The towers would be 650 feet high, nearly 100 feet higher than the Wash- ington Monument at Washington. The preliminary drawings by Cass Gilbert show masonry towers (encasing the steel skeleton) and a conception of surpassing beauty, al- though the use of encasing masonry that no longer serves a useful purpose may be open to criticism. The proposed bridge over Kill von Kull, to be built by the Port of New York Authority, will contain a steel arch span of 1650 feet span, equaling that at Sydney Harbor, Australia. Prof. W. H. Burr and Gen. George W. Goethals are consulting engineers for the Kill von Kull Bridge, and Cass Gilbert is architect. Modern Opening Bridges One of the difficult problems confronting the modern bridge engineer is that of obtaining a pleasing treatment of the opening bridge, a type generally considered to be inherently and hopelessly ugly, and which many engi- neers spend no effort to make anything else. Recent drawbridges built and now being built in Chicago, however, possess distinct architectural merit. Among those now com- pleted are the Michigan Avenue Bridge, the WEST SUMMIT STREET BRIDGE, WARREN, O0.—DETAIL [ 209 | BRIDGE ARCHITECTURE ROBERT STREET BRIDGE, ST. PAUL, MINN. West Madison Street Bridge and the Frank- lyn Street Bridge. These bridges are designed in collaboration between the engineers of the Department of Bridges of the City and the architect of the City Plan Commission and the results speak for themselves. The treatment of the approaches to the Michigan Avenue Bridge is very elaborate, as befits such an important crossing, and in- cludes provision for statuary on the four main pylons and for wide plazas. EK. H. Bennett is consulting architect to the Plan Commission and to him is much of the credit due for the results obtained. At Wilhelmshaven, Germany, there has recently been constructed a double swing bridge of unique design, the trusses combining the cantilever and suspension principles. Probably the most ornate opening bridge ever built is the Tower Bridge over the Thames at London, opened for traffic in June, 1894. This is the joint work of J. W. Barry, as engi- neer, and Horace Jones, as architect. The length of the bridge is about 800 feet, com- posed of a channel span of 200 feet clear open- ing, and two fixed flanking spans of the sus- pension type. The very elaborate towers have a skeleton of steel, encased in granite, stone and brick. An unusual feature is the provision of a foot walk at a clearance of 141 feet over the river, for use when the draw is open, and reached by elevators in the towers. The Anacostia Bridge at Washington has a very neatly designed bascule span of 100 Sieg agitate ioe once GLENS FALLS, N. Y. BRIDGE STAIRS [ 210 ] a BRIDGE feet. clear channel opening. This bridge, con- sisting of a series of steel arch spans, was built in 1902, under the direction of Col. John Biddle, U.S. A., and W. J. Douglas, engineer of bridges. The Cherry Street Bridge over the Mau- mee River at Toledo, Ohio, comprises a bascule channel span with a clear opening ARCHITECTURE of 200 feet flanked on each side by heavy concrete piers which conceal the operating parts, as is the case at the Anacostia Bridge. The effect of the Toledo Bridge is marred by the omission of the pylons planned by the late Arnold Brunner. (Plates CXCI, CXCII, CXCIII, CXCIV, CXCV, CXCVI, CXCVII, CXCVIII & CXCIx.) Pani HITECTURE = A ARC BRIDGE v06I—SUAANIONA ‘SVTONO ‘f “M ¥® NOSIMOW ‘S ‘OHD—ADCIYNE ANNAAV LOOLLOANNOO—9D ‘d ‘NOLONIHSVM—IIXXXD FLV Id ee ee fe a oe a Oe rae on, ¥ ¢ , saree tan aye BRIDGE ARCHITECTURE SHHHUNIONA ‘SWTONOG f 'M ® NOSTHOW ‘S ‘OHD P06l GULWIdNOO—ADCINE ANNAAV LAOILOHANNOD—D “d ‘NOLONIHSVM—HIXXX) ALWId engin 213 | [ BRIDGE: ARCHITECTURE 806I—YAANIONG ‘ADWINO “H ‘(H—ADCIYd ANVT LONTIVM—Vd ‘VIHdTACVIIHd—AIXXX) BLV 1d BRIDGE ARCHITECTURE WAANIONGA ONLLIOSNOO ‘NOSLVM ‘f “M “HAANTISNA ONINDISAC “ALVOTHA “WV UAAIM AMOOU UAAO NVdS LOOA-087 AO HOUV ALAYONOD—OTHO “ANVTAAHTO—AXXXOD ULV Td CS gel Ca ar oe i aa [215 | Ke Cee eee BRIDGE ARCHITECTURE MAANIONA ONILIASNOO ‘IHSALGOW Hd TV ‘SHAANIONG ONINDISHC “OD ONTYHANIONGA NYOdSO AHL—ZI6I-MAAIM AAWAVW AHL UAAO ADGINA LAAULS AUYAHO—OIHO ‘OGATOL—IAXXXO ALVId [ 216 ] BRIDGE ARCHITECTURE YHANIONA DSNILTASNOD ‘IMSAfLGOW Hd TV¥ ‘SYANDISAC “OD ONIMAHNIONA NYOEdSO HHL ZI6I—MAIA MOUG—YAAIY AAWOVW AHL YHAO ADGIUA LAHULS AUYHAHO—OIHO ‘OGHTOL—-IIAXXX) ALVId Nhe [217] BRIDGE ARCHITECTURE STAVG ‘H “4 Ad GANDISHC ANGINA AVMHOIH ALAYONOD—Vd ‘NMOLNATIV—HIAXXX) ALVTd BRIDGE ARCHITECTURE OLUMBUS, OHIO—KING AVENUE BRIDGE OVER THE OLENTANGY RIVER—1914 ” LA PLATE CXXXIX—_¢ WALTER BRAUN & WILBUR J. WATSON, ENGINEERS BRIDGE ARCHITECTURE YAANIONG ‘NOSLVM ‘f YNATIM—616I—YAAIY ADNVINGAIO YAAO ADGIUA LAAULS GHIHL—OIHO fraarierar uu, | patron, sisal Lass J nnn, PRT | T i uuu uuu) ul uu] mama wail) usual) aus aa e ; = sa . ” Qo Ma “a uo q os wine * ‘SAGINNTOO—IXD ALVId | sasod) saath ssl) stl sl coal al ee amy «tits fit E 7 - owe %, oy ae BRIDGE ARCHITECTURE PLATE CXLI—COLUMBUS, OHIO—BROAD STREET BRIDGE OVER THE SCIOTO RIVER—1921 BRAUN, KNOLLMAN & FLEMING, ENGINEERS [ 221 | HITECTURE = A ARGC BRIDGE LOMLTHOYVY ONLLTNSNOD “WALLOd ‘d ‘WW ‘SHAHNIDNA ‘NMOUM ‘d “M CNV NOSLYM ‘f YOATM—Ie6I—YHATY NIYOVHO AHL YHAO ANGINA AVMHOIH—OIHO ‘APGHDNOTIIM—IITXD ALVId f 299") BRIDGE ARCHITECTURE oO PLATE CXLIII—WILLOUGHBY, OHIO—BRIDGE OVER THE CHAGRIN RIVER—1921—DECK VIEW—WILBUR J. WATSON AND W. P. BROWN, ENGINEERS. M. P. POTTER, CONSULTING ARCHITECT [ 223 | ARCHITECTURE BRIDGE SYUAHNIONA “NIMUT “M ‘O CQNV TTAMMOOY THONVS—YAATHY NIMOVHO AHL YAAO AOGIYA AVMTIVY—OIHO ‘ATHONOTIIM—AITXD ALV Id [ 224 ] BRIDGE ARCHITECTURE SHAANIDNA SONLLIOSNOD ‘NOSLVM YAGTIM GNV ONITIOR’ SVHO ‘NAMOUNA A “d O—~OD ONIMHANTONGA TAALSALAYONOD AHL Ad NOISHA—€16I—YHATY SANVE AHL YAAO AOGTHA SOAVIN— VA ‘CNOWHDOIY—ATXO ALVTd © _ | ARCHITECTURE BRIDGE SHAANISNA DSNILIASNOD ‘NOSLVM HOGTIM GNV DNITION ‘SVHD ‘NAMOYNE “A ‘d “O—OD ONIYAANISNA IAHLSALAYONOO AHL Ad GANDISHG—t16I—YAATY SHINVE AHL YAAO ADAG SOAVN—VA ‘GNOWHOTY—-IATXO ALWId | [ 226 BRIDGE ARCHITECTURE YAANIONA ‘NOSLVM ‘ff HOATIM—SI6I—HDIH Lada col YH ATH VOOHVANO YHAO MOCGIMa—OIHO ‘NOUNV—IIATXO ALVId HITECTURE 7 oon ( BRIDGE AR DNOT LAXA 000F—9T6I—YAATY VNNVHANOSNS AHL YAAO AOGIUA GVOUTIVU—Vd SUNASIMYVH—IIATXO ALVId Bint D Gil ar he Col el hy GU Re NOLAVG ‘UATIGM GUVMOH AG OLOHA 926I—SUAANIONGA ¥ SLOU.LIHOUV ‘NIVIHAAINVHD ‘ff 8 HLINS “HY A—aOCIYd MYVd GNVTISI—OIHO ‘NOLAVG—XITXO ALVId [ 229 | BRIDGE ARCHITECTURE MYOA MAN ‘GOOMYAGNA ¥ GOOMYGANA Ad HdVUYOOLOHA PC6I—YAANIONGA “LANISSAGYA “A—NVdS LOOS-0€F}—ANIAS AHL YHAO AOCTHYA—HONVYA—TO ALV Td 230 | [ BRIDGE ARCHITECTURE tary = a . Fe 916I—HHANIONA AMIHD ‘AVY ‘¢ ‘OH9—'H “UM 8 “TI ‘G—LONGVIA MOONNVHYANDL—ITI) ALVId _— sr BRIDGE ARCHITECTURE ‘_ ae See Ble SUHANIONG ‘AVY ‘f D ¥F HSNA NIOONIT O1l6l LIINA—YAATY AYVMVIAG AHL YAAO “YUM BF “Td AO LONGVIA ALAYONOO—dV9 YALVM AYVMVIEAC—IITO ALVTd i H g } 5 i 4 meets See~---veb Bow---- cel bow .08 B [ 232 ] re ss TURE ~ A BRIDGE ARCHITEC LODLINOUVY ONLLINSNOD ‘LYHaHOL “M “A UAANIONG ‘SIAVG “H ‘d—aDCIYd TVINONWAN LAHULS NOLONTASVM— TA ‘NOLONINTIM—INTO ALVId [ 233 | BRIDGE ARCHITECTURE LOULIHOYUV “LYAdHOL “M “A YAANIONG ‘SIAVC “H “d—ccol—HOCINA TVIMOWAW LAAULS NOLONIHSVM—THC ‘NOLONIWIIM—AITIO ALY 1d [ 234 ] BRIDGE ARCHITECTURE nis: 2abbitintcoin aie mt, sa Sea es PLATE CLV—WILMINGTON, DEL.—WASHINGTON STREET MEMORIAL BRIDGE B. H. DAVIS, ENGINEER; V. W. TORBERT, ARCHITECT [ 235 | BRIDGE ARCHITECTURE YOLdTNOS “YO.LOOUd YALLSINTHd ‘V “LOBLIHOUV ‘NMOUd NNATS—AOCIUA LAAULS ..0,.—D ‘d ‘NOLONIHSVM—IAIO SLY Id Rs 236 | [ URE a A ( BRIDGE ' ARCHITE THHLS ALAY ONOD HHL SYAHNIONA “WHOA MAN “OD ONIYHAUNIDNG 8I6I—HHAIN WIAHVONONOW AHL YHAO AOCIYE ALAYONOD—VA “M “LNOWYIVA-IATD ALV Id BRIDGE ARCHITECTURE SLOALIHOYV ‘NOSNOYUAA F ANHGOOD ‘WVeD YAANIONG “Uf “NATTV ‘d YNVYA—ST6I—ADCIUA OTTIMAVO— TVD ‘ODI NVS—IIATIOD WLW Id [ 238 ] BRIDGE ARCHITECTURE NVdS LOOJA-00)—YHATY Idd ISSIS tS) YAANIONA ALIO “NATAdd VO “M IN AHL YWAAO ADGA NATHdd VO AHL NNIW ‘SITOdVANNIW—XITO ULV Id TURE 4C ARCHITI vy A af BRIDC SLODLIHDYV GNV SHAANIONG “ONT ‘AVG ® ONIN ‘ZLIOL 926I—HAATH IddISSISSIN AHL YAAO ANGINA LAGULS LYAGOU—NNIW “TNVd “LS—XTO ALVId es = | i ; x | i g | oe ee tee) aed ARCHITECTURE BRIDGE YAANDONG SNEVMS ‘a (OWD—HAAIY OVININYHIN AHL YAAO AOCIYE ALHYONOD— SsvW “THHYHAVH—IXTO ALV Id HITECTURE + A fb AR BRIDGE VAGNGD ‘Sauaud NAITINL AM OLOHA SHAANIONA “OO ¥% UAONITION “WW : LOGLIHOYY ‘NIOUVD ‘W—9261 GALA Td NOD—ANOHY AT YAS ‘NILNA LNOd—VAHNAHS—UXTD ALVId ‘ “ >i. 8 Sie es BRIDGE ARCHITECTURE YHAUNTIONG ANYNOLA S r Vd “N—HTISSOW VI HOS ONITIVA AG LNOd—ANIVUNOT-INXT) ALVId [ 243 ] ARGHITECTURE BRIDGE 1 ae aONAUOTA ‘IOOUM A OLOHA c06I—YNOAVD ALNOd—HWOY—AIXID ALVId es i BRIDGE ARCHITECTURE cS a woud “da WOUd OLOHd 668I—O.LHHUEND ALNOd—HNOY—AXTO ALVId BRIDGE ARCHITECTURE Saree Neon Z Setar ~ += = ee Ee. e Sa ce \ ~~ \ eS: Sae ae PLATE CLXVI—SCARSDALE, N. Y—WESTCHESTER COUNTY PARK BRIDGE—1915—JAY DOWNER, CHIEF ENGINEER DELANO & ALDRICH, CONSULTING ARCHITECTS. ARTHUR G. HAYDEN, DESIGNING ENGINEER BRIDGE ARCHITECTURE C%6I—HAAIN OVNOLOd AHL YWAAO HOGTHA AHH LLOOS SIONVYA AHL) “a ‘NOLONIHSVM—IIAXTO ALVITd [ 247 | BRIDGE ARCHITECTURE dearentihte paprgeine panei PLATE CLXIX CALIFORNIA STATE HIGHWAY BRIDGES—MODERN CONCRETE HARLAN D. MILLER, STATE BRIDGE ENGINEER [ 248 | ARGHITEOQTURE BRIDGE YAHANIONA ADGA ALVIS ‘YATIUN ‘G NVTYVH Ad da on TEE Hussag teat he ite ae NAa SONNURUSAAN guupanatnyE ‘ayerenbenye senvannner tities er YISHAU—ADGTYd AVMHADIH—VINYOATTVO—XXTO ALVId Sri ne rr #Utevevetex | UAGRSE LOS ervey ever ge Sh sane BRIDGE ARCHITECTURE YHANIONGA “NOSLVM ‘f YNATIM 916I-SLUAULS YAAO GVOUTIVY WOVUL YAO ONIAYYVO SHHOYV ALHYONOO—OTHO ‘GNVTHANTO—IXX1) WLW Id [ 250 BRIDGE ARCHITECTURE YHAUNIONGA ‘NOSLVM ‘f°M AG GANDISHG—916I—LAHULS YAAO AOCIYA AVM TIVYE—OLHO ‘GNVTIAANTIO—IIXX1ID ULV Id ese | [ 251 ] a ee ee eee ——_ «| / a“. _ vy . SHHUNIDNA “OD ¥ HANIAYHD “A f—HAATY SHINVE AHL YAAO ADCGINd GVOUTIVU—VA ‘GNOWHOI—TIXX TD ALV Id ARCHITECTURE Vee il BRIDGE ARCHITECTURE E 1 I BRID( ‘OO DNIASTTEANd LIOULAG Ad OLOHd SUAYNIDNG “OD DNIVAUNIDNA NYOUSO AHL—c06I—MAAYD VOVNVD LSAM YHAO ADC — AON UHI YAH—ALXX'TO ALV'Id [ 253 | BRIDGE ARCHITECTURE "M ‘£°M AM OLOHd C06I—MUVd VIMOLOIA NHANO NI HOGIYA AVMTIVE— LNO ‘STTVA VUVOVIN—AXXTO ALVTd [ 254 ] BRIDGE ARCHITECTURE PLATE CLXXVI—CINCINNATI, OHIO—BRIDGE DESIGNED BY GARBER & WOODWARD, ARCHITECTS [255 ] ARCHITECTURE E q A BRID¢ YAANIDNA DONELTOSNOD “NOSLVM “f HOPTIM “YHANTSNG ALIO YONVHS “TH 606I— AY NYAH.LAOS YHAO LHAYLS HLA ONIAWYVD ADCIYd— VA ‘DYNGHONAT—IIAXXID ALVI1d en, a en — te ~ 256 | TURE ~ A BOR Go Be SAL GEE Le Es SI6I—YHHNIDNG * SHLYHNA “H SWf—THVLAG—LONGVIA LHAYLS G—VA ‘SYUNGHONAT—INAXX'ID ALVId HEL EG Bes BRIDGE ARC els WL, O1T6I—MAHYO OYNASLOd ATLLIT HHAO HOCIYE ATd ALHYONOO—VW1A ‘ATITANOSMOVI—XIXX1) ALV Id Sere To « ? 5 og ie ilies sa co : fe as La E OTRAS et SORE bes Lactose bs NOSIVM “£ HWAATIM AG OLOHd GNY NOISHG “ya BRIDGE ARCHITECTURE NED BY WILBUR J. WATSON SIG xE IN NORTH CAROLINA—DE HWAY BRIDC RETE HIG 1 4 ONC .] A PLATE CLXXX—A SMALL (¢ TURE y ia A BRIDGE ARCHITEC YHUNIONA ‘NOSLVM “ff WO TIA 916I— LHAYLS LINIWOS NO YHATY ONINOHVW AHL YHAO HOCGIYd ALAYONOD—OIHO ‘NHYYVM—IXXXTO ALV Id Pp. me Rs 6 Ee io [ 260 ] BRIDGE. ARCHITECTURE ~’ 6s eit tate tape steatea, sg We WEARS won Gn ah oes A AEM LM he AMM Fee he Ths) wane) Wy ; oF ek iNen geen eh ae 4S bee AAG Neg “an 4 Ge Ms A, Pie 4 rig ere PLATE CLXXXII—CHESTER, PA.—MEMORIAL BRIDGE—1926—CLARENCE W. BRAZER, ARCHITECT [ 261 | 4 ARCHITECTURE EK ~ I BRID¢ “KN ‘ASOQOVUAS “OO ALIIOHLIT VOVGNONO WOUd OLOHd ‘ft °N YIVIOLNOW—V-IIXXX1)D ALV Td ALYYONOD LSVOUUd dO SLAdVYVd—HOCTYHH WYVd ALHYONOD BRIDG oe bez, eS oe, ee E ARCHITECTURE LXXXIII-B—MONTCLAIR, N. J—CONCRETE PARK BRIDGE at A PLATE C PHOTO FROM ONONDAGA LITHOLITE CO., SYRACUSE, N. Y. BRIDGE ARCHITECTURE Fl6I—ADGIHd AVMHDIH ALAYONOD TIVNS—ATTVO “LNOWCAId—V-AIXXX19 AHLV Id 264 | | Fl6I—ADCIYA HOYV ALAHONOD TIVIANS—AITVO “LNONWGHId—d@ AIXXXTD ALVId oa faa — Ee O ea = _ on SS fan =< ea & (a) — fan BRIDGE. ARCHITECTURE MUOK MAN ‘GOOMYAGNA ¥ GOOMYAGNA Ad OLOHd ATALS NOISSIN NI STVLYOd ADGIYA—VINHOAITVD “AGISHHATH—-AXXNTD GL Id [ 266 ] BRIDGE ARCHITECTURE PLATE CLXXXVI—CINGINNATI, OHIO—FOOT BRIDGE AT EAST SIDE HIGH SCHOOL GARBER & WOODWARD, ARCHITECTS [ 267 | TURE ARCHITEC + ol BRIDGI SHHANIDNA “NOSLVM “f YOATIM 8 NOVY YHLTIVA 9c6l LIINA—YaAIY GVIN AHL YHAO ADCIYd LAAULS AVTIGNIA—OIHO ‘NOLAVG—IAXXX1) ALVId > em mw 4 268 | WN TA | a a ATC RTT TTT TTT rea i iit tHITECTURE ARC E > I BRIDC 9261 YHOU NIDNA ALVOTHA IW “V—YuATY AMDOY HHAO HOGIHE GUVITIIH—OIHO ‘GNVTHAYT Y N J-MMNAXXXTO ALVId F269] BRIDGE ARCHITECTURE A PLATE CLXXXIX—BAVARIA—DETAIL OF CONCRETE RAILWAY BRIDGE—M. BEUTEL, ENGINEER—1908 PLATE CXC—BOSTON, MASS.—CONCRETE BRIDGE OVER CHARLES RIVER—DETAIL [ 270 BRIDGH ARCHITECTURE TURE Cc" tHITE AR( BRIDGE ADCIYE DNEIMS ATANOG—ANVINYED ‘NAAVHSWNTHHTIM—HOX) ALV Id BRIDGE ARCHITECTURE v68I— LOALIHOYY ‘SHNOf HOVYUOH “YHANIONGA ‘AYUVE “M f—HOGIUE YAMOL AHL—NOGNOT—IIDXO ALVId «ttl AHL areN tie [ 273 ] ARCHITECTURE BRIDGE [ 274 ] BRIDGE ARCHITECTURE YAUNIONA ONILINSNOD ‘THSHLGOW HdTVu “SHAANIONA ONINOISHO “OO DNIYWHANIONGA NUuOdsO AHL—Zl6I—Ya AIM AAWNOVN AHL YHAO ADC LAXULS AWHAHO— OHO ‘OdATOL—ADXD ALVTd | [ 275 BRIDGE ARCHITECTURE Bs ae a iy es Se SE ics I =m: ¥ AN bts SR PASC US ; > N MEE MARITAL SBRE POR RLeNwe Aa riches SRIAL RRIOG 1 Cow 79 °6N +? OFF tk SHE NH . Z TRO Ose q KeN1 s we - eae PRET stb EW GtkcRe LINUKARTE BERT Dey ek a INGRARLE JINN & An: » : oe te ec ne ee eect saeecdheenseurenipesvantetvesoeesner unas Deaaneeeanasopeeenenties naa aot ‘ EA POE IM aC SRI ASR AN ND MAN tn Soe an Basi 9 . pea aN ae a a ae ei Ti as ie - PLATE CXCVI—WASHINGTON, D. C.—THE ARLINGTON MEMORIAL BRIDGE OVER THE POTOMAC—BASCULE SPAN COL. CG. 0. SHERRILL, CHIEF ENGINEER; JOHN L. NAGLE, DESIGNING ENGINEER; W. J. DOUGLAS, CONSULTING ENGINEER. McKIM, MEAD & WHITE, ARCHITECTS UNDER CONSTRUCTION (1927) [ 276 | Cae oe a hol. ae BRIDGE ARCHITECTURE HHL Ad LOALIHDYY DNILIOSNOD “‘LLANNAd “HA “ODVOIHO ‘SHOdTYd JO LNAWLY Vdd GaNDISHG—AAV NVOIHDIN NO YAATH ODVOIHD AHL YHAO ADCIYAMVYG—TII ‘ODVOIHO—IIAOXD ALVITd i ] [277 BRIDGE ARCHITECTURE LOALIHDYV DNILTASNOD “LLANNA “H “A “ODVOIHO AO ALIO AHL AO SHOCTYA JO LNANLYVdad AHL Ad GANDISAG YUAAIM ODVOIHD AHL YAAO ADGIYA LAAULS NOSIGVW LSHM—TI “ODVOIHO—IIIADXD ALVTd PEERERELEELES eee Se Se [ 278 ] BRIDGE ARCHITECTURE LOU&LIHDYV ONLLIONSNOD ‘LLANNAG “H “A ‘OOVOTHD AO ALIO HHL AO SHOCTYA HO LNANLYVdad AHL AG GANDISHG ‘WHATH ODVOIHD AHL YUAAO ADGINA LHAYLS NITHNVYA—TI ‘OOVOIHD—XIOXO ALVId scenic: Sap, ee Fei gh * eel, [ 279 ] POSTWORD HAT will be the Bridge Architecture of the future? We have reviewed briefly the past history of the art and its present condition, and have seen that the principal factors controlling the development have been— First: The general state of development of the people. Second: The standards of technical and artistic skill. Third: The materials available. Fourth: The methods of transportation. Applying these factors to the immediate future, we may safely assume that the general material development of civilized peoples will not recede, and there are unmistakable evi- dences of a greater appreciation of things artistic and pleasing to the eye. The new demand will lead to higher standards of artistic taste, and especially as applied to the implements of production, trade and transportation, which in the past have required only technical skill. The materials available for bridges, which - in the past included successively timber, then stone masonry, then iron and steel and lastly the combination of concrete and steel, are now all available at one time and may all be employed in a single structure. To those engi- neers who have made a most careful study of all materials, it seems certain that stone masonry will continue to be the material par- excellence for the best and most monumental structures, when its properties will allow its use. It seems extremely doubtful that rein- forced concrete will displace exposed structural steel for many bridges, especially those of long span. Doubtless, our scientists will soon pro- duce for us a non-corrodible steel or steel alloy, which will reduce the present high maintenance cost of steel bridges and will probably tend toward a return to the light, airy forms which this material permits and which has a charm all its own. The newest material, reinforced concrete, has, as shown by the illustrations, been in use only about a quarter of a century, in which time it has largely displaced stone masonry and steel for bridges of moderate span and for long viaducts. This material possesses great possibilities for artistic treatment, but so far most of the work executed therein has followed and imitated the exterior forms of stone masonry or exposed steel instead of frankly expressing its own peculiar and useful nature. There is a tendency among engineers today toward extreme specialization, certain engi- neers specializing in reinforced concrete work, some in steel and others in other materials. While there may be some advantages in such specialization on the part of assistant design- ers, it stands to reason that the bridge en- gineer or architect, on whose judgment rests the decision as to the proper materials to use for a certain structure, must be a man [ 280 ] BRIDGE ARCHITECTURE thoroughly familiar with all materials and prejudiced in regard to none. Above the specialist must stand the architect-engineer of broad mind and broad training if good designs are to be obtained. Methods of transportation change from time to time, requiring great changes in the design of bridges. We see the narrow struc- tures of the Romans, designed for chariots and cavalry and infantry, the still narrower roadways of the Middle Ages, some of them too narrow for vehicles of any kind. Then, we see the revolution in bridge construction brought about by the invention of the steam railroad a hundred years ago, and now again we see transportation conditions entirely revolutionized by the development of the automobile, attended by a tremendous ex- pansion of improved highways, requiring numberless wide, permanent bridges. Indeed, many observers see a complete revolution in our social life as a result of the universal use of the automobile, a new era of decentralized homes and factories, depending upon good roads and good bridges for quick and safe transportation. The key to our newest civilization seems to be the improved highway; may it be made not only commodious and permanent, but beauti- ful as well—especially the bridges that carry it over streams and other obstructions, and constitute its most monumental features. That this result may be accomplished, may we not look forward to much closer coopera- tion than now exists between the engineers and the architects? In earlier days it was possible for one per- son to acquire the artistic training and scien- tific knowledge needed to perform the func- tions of both architect and engineer. This was accomplished by Sir Christofer Wren and by Jean Rodolphe Perronet. In their time the preparation required for these professions was comparatively simple, but modern conditions demand far more training and experience than can be expected from an individual. Collaboration between architects and engi- neers is, therefore, necessary, and should begin with the inception of the work. It is evident that when the general design of a bridge is left solely to an engineer whose training has been entirely along scientific lines, and then an architect is called in con- sultation, the latter must necessarily confine his work to decorative treatment. On the other hand, when the general design of a bridge is entirely in the hands of an architect who, perhaps, has had inadequate scientific experience, the engineer is limited to the thankless task of giving sufficient strength to the structure, the general conception of which violates the rules of scientific design. The best interests of bridge architecture can be served in the future through the close cooperation of architect and engineer. [ 281 ] APPENDIX “A” | BIBLIOGRAPHY OF PRINCIPAL WORKS ON BRIDGE ARCHITECTURE Gauthier—Treatise on Bridges—Paris 1728. Geo. Semple—A treatise on Building in Water—Dublin 1776. Thomas Pope—A treatise on Bridge Architecture—New York 1811. E. Gauthey—Traite’ de la Construction des Ponts—Paris 1816. Hann and Hosking—Theory, Practice and Architecture of ee London 1842. John Wels Biiiees si case 1843. Smiles—Lives of the Engineers—London 1861. Jeaffreson and Pole—The Life of Robert Stevenson—London 1864. KE. Degrand—Ponts en Maconnerie— Paris. M. Paul Séjourné—Grandes Voutes—Paris 1913. W. Shaw Sparrow—A Book of Bridges—London 1914. George C. Mehrtens—A Hundred Years of German Bridge Building —Berlin 1900. William Emerson and Georges Gromort—Old Bridges of France— 1925. Encyclopedia Britannica—Eleventh edition—1911. The Builder—London. The Engineering News Record—New York. Engineering—London. 7 The American Architeet—New York. The Architectural Record—New York. The Architectural Forum—New York. [ 282 ] ABUTMENT AGGREGATE AQUEDUCT ARCADE ARCH Arcu Ris Arcu RING ARTICULATED BALUSTRADE BaASCULE Basket HANDLED ARCH BATTLEMENT BEAM BENT CANTILEVER CARTOUCHE APPENDIX “B” GLOSSARY OF TECHNICAL AND ARCHITECTURAL TERMS USED (Based upon Webster) (of a bridge) The support at either end of the entire bridge. (of concrete) The particles (of stone, gravel, etc.) which are united by the cement. A structure for conveying water over a river or hollow, more specifically called an aque- duct bridge. A series of arches with the columns or piers which support them. A structural member, usually curved and made up of separate wedge-shaped vous- soirs, with their joints at right angles to the curve. Scientifically, the arch is a means of spanning an opening by resolving vertical pressure into horizontal or diagonal thrust. Used to designate a free standing arch having a width much less than that of the bridge, usually in pairs, and supporting columns. The arch proper, used to designate the arch without the spandrels, fill or other elements, and applied to arches which are the full width of the bridge. Put together with joints, as a truss. A row of balusters (vertical supports) topped by a rail, serving as an open parapet. (bridge) A counterpoised or balanced draw- bridge, opening in a vertical plane. An arch formed in the shape of a basket handle, may be either three or five centered. A parapet consisting of alternate solid and open spaces, surmounting the walls of an- cient fortified buildings. A structural member, usually straight, sup- ported at each end. A frame put together on the ground and then raised to a vertical position. Also used to designate the vertical supports of steel bridges when assembled in place. A projecting member; in a bridge, either of the two beams or trusses projecting from piers towards each other, their far ends free, or connected with a joining member. A tablet for ornament, usually for receiving an inscription. CENTERING COPING CORBEL CORNE-DE-VACHE CORNICE CROWN CULVERT CUTWATER DENTIL ENTABLATURE EXTRADOS FASCES GABLE GIRDER GRILLAGE HEADER INTRADOS [ 283 ] The temporary substructure which supports the permanent construction. The highest or covering course of a wall, used in bridge work to designate the finish- ing course of the spandrel walls. A projection from the face of a wall, sup- porting a superincumbent weight. (cow’s horn) Used to describe the prac- tice of splaying out the ends of an arch by gradually increasing the span. The horizontal member which crowns a composition; may consist of several courses of masonry. (of an arch) The vertex, or top part of an arch or arched surface. A small opening or waterway under a high- way, railroad, etc. The sharpened end of a pier, built with an angle or edge to better resist the action of water, ice, etc. : A small rectangular block in a series pro- jecting like teeth, as under the corona of a cornice. The architecturally treated wall resting upon the capitals of the columns and sup- porting the pediment or roof plate. The exterior curve of an arch; the exterior surface of an arch ring. A bundle of rods, having among them an ax with the blade projecting, borne before Roman magistrates as a badge of authority. The vertical, triangular portion of the end of a building. An iron or steel beam of economical section, either made in a single piece or built up of plates, angle bars, etc. A framework of sleepers and cross beams of timber or steel, used in foundation work. A masonry unit laid with its greatest dimension at right angles to the face of the wall. The interior curve of an arch; the inner surfaces of the arch ring. KEYSTONE LINTEL MEDALLION PARAPET PEPERINO Pier PILASTER PILE PonTOOoN PorRTAL PYLON Quay QUOINS Glossary of Technical and Architectural Terms Used—Continued The voussoir at the center of the crown of an arch, which, being the last to be placed, is regarded as binding the whole together. A horizontal member spanning an opening, used to support superimposed loads. A shape resembling a large medal, as a circular, oval, or sometimes square tablet or panel bearing a figure or figures repre- sented in relief, a portrait or an ornament of such a form, as a sculptured decorative architectural member or feature. A low wall or similar barrier, as a railing, especially one to protect the edge of a platform, or a bridge, etc. A dark colored volcanic conglomerate, much used for buildings and bridges in Rome. A support for either end of a bridge span. An upright architectural member, rectan- gular in plan, structurally a pier but archi- tecturally treated as a column with base, shaft and capital. A large stake or pointed timber, driven in the earth, used to support piers and abut- ments and sometimes used as a direct support for superstructures. A flat bottomed boat, or any float, used in building bridges, the boats usually con- nected with beams. In bridge building, the space at either end, between the first two principal trusses in a truss bridge or a door, gate or entrance, especially one that is grand and imposing. A gate way building having a truncated pyramidal form. A solid artificial landing place, usually of masonry, at the side of a river, etc. The selected pieces of material by which - the corner is marked; in stone the quoins consist of blocks larger than those used in the rest of the building and cut to dimen- sion. Reurevine Arcues’ An arch used to relieve another mem- ber, as a lintel, of part of its load. RETICULATION RIseE SADDLES SCAFFOLDING SEGMENTAL SKEWBACK SPAN SPANDREL STRAIN STRESS STRETCHER TRESTLE Truss TuFA VoISsSOUR [ 284 ] Masonry work constructed, or faced, with diamond-shaped stones, or square stones placed diagonally. (of an arch) The vertical ascent of the intrados curve. Blocks over which the cables of a suspen- sion bridge pass, or to which they are anchored. A supporting framework for temporary supports, usually of timber. An arch of which the intrados forms the segment of a circle, meeting the jambs or imposts at an angle. The course of masonry, the stone, or the plate, having an inclined face against which the voussoirs of an arch abut. The spread or extent of an arch between abutments or of a beam, girder, truss, roof, bridge, or the like, between supports; also, the portion thus extended. The irregular triangular space between the extradox curve of an arch and the enclosing right angle; or the space between the extra- doses of two contiguous arches and a hori- zontal line above them. The deformation, or distortion, of a body due to stress or force. The force with which a body resists external forces. A masonry unit laid with its greatest dimension parallel with the wall. A braced framework of timber, piles or steelwork, for carrying a road, railroad, etc., over a depression. An assemblage of members such as beams, bars, rods and the like, so combined as to form a rigid framework; that is, one that cannot be deformed by the application of external force without deformation of one or more of its members. A porous rock formed as a deposit from springs or streams, as travertine. Any of the tapering or wedge-shaped pieces of which an arch is composed. APPENDIX ‘‘C” BIOGRAPHIES N the early history of modern bridge architec- | ture, three great British engineers have taken a prominent part. These men are John Rennie, Thomas Telford and Robert Stephenson. The first is best known as a bridge engineer, the second as a highway engineer and the third as a railroad en- gineer; but they all designed great monumental bridges which marked distinct advances in the development of the art. JOHN RENNIE John Rennie, the architect of three great London bridges, including the New London Bridge, and many other engineering structures, was born at Phantassie, Scotland, on June 7, 1761. His father was a small farmer, as his ancestors had been for generations. Young Rennie was well educated, completing his studies at the University of Edin- burgh in 1783, and immediately started upon his professional career, designing canals, docks and bridges, at which occupation he spent the rest of his life, allowing himself but little pleasure and having but limited interests outside of his own work. His death occurred in 1821 and he was buried in Westminster Abbey, near the tomb of Sir Christofer Wren. THOMAS TELFORD Thomas Telford, the designer of the Menai Straits Suspension Bridge, was also Scotch, having been born at Eskdale, Scotland, in 1757. His father was a shepherd and the son was brought up in poverty, learning the trade of a stone mason, at which he labored for many years, educating him- self by reading in his spare time. This self-educated man had a great love for poetry and music. Much of his verse is in print. While the greater part of Telford’s life was spent in building bridges and harbors, he is best known for the type of paved roads which he built and which are still known as Telford roads, the principle being that of the macadam road with selected sizes of stone for the various courses, large stone for the first course and progressively smaller for the upper courses. Telford was active in the formation of the Institute of Civil Engineers, was elected its first president in 1820 and left it a legacy upon his death in 1834. This self-educated son of a Scotch shepherd, who be- came a gentleman of wide culture, the friend and loved companion of poets and writers, is buried in Westminster Abbey. ROBERT STEPHENSON Robert Stephenson was born in 1803, the only son of George Stephenson, famous as the inventor of the railroad locomotive. Robert was educated at private schools and at the University of Edin- burgh. While the father’s greatest achievements were in the development of the railroad engine, Robert’s principal work was in the construction of the great bridges required to carry the railroads over wide rivers. His best known work is the Britannia Bridge. He died in 1859 and was laid at rest in Westminster Abbey, near the tomb of Thomas Telford. JEAN RODOLPHE PERRONET Jean Rodolphe Perronet, the pioneer French bridge engineer, son of a Swiss soldier in the ser- vice of France, was born at Surennes, near Paris, October 8, 1708. At the age of six, Perronet was [ 285 | BRIDGE ARCHITECTURE taken to visit the Tuilleries. The young Prince Louis XV, for whom elaborate amusements had been arranged in the adjoining gardens, was at- tracted by Jean and invited him to join his games. This was the beginning of a friendship which made Perronet the recipient of many unusual personal favors and confidences. Perronet intended to enter the Genie Militaire, a military engineering school, but since only three candidates were admitted at a time, and these selected by promotion, he changed to the study of architecture. In 1725, M. Debeausire, a Parisian architect, employed Perronet as assistant in charge of high- way and sewer construction. In 1745, he was appointed administrator and inspector of roads and bridges for the district about Alencon. Two years later M. Trudaine Sr. founded a school of engineering in Paris, of which Perronet was made Inspector General and Director. About this time, M. Hupeau, Chief Engineer of Roads and Bridges of France, entrusted to Perronet many of his duties. Meanwhile Perronet’s reputation as an instructor in mathematics, physics and archi- tecture made his services valuable as a consulting civil engineer. The Nogent-sur-Seine, the Sainte- Maxence, the Concorde at Paris and the Nemours bridges, also the Bourgogne and Yvette canals are among his achievements. By order of the Council of State, Perronet was named Inspector General of the Salt Mines of France in 1757, which office he held until 1786. As an engineer, Perronet displayed unusual skill as a designer and administrator. His personal qualities of kindness, patriotism, amiability and arduous devotion to his profession won him the | esteem of the London Society of Arts. The last years of Perronet’s life were devoted to a compilation of lengthy memoirs. He died at the age of eighty-six, February 27, 1794. [ 286 ] GENERAL TEXT INDEX Note: The various bridges described are indexed by location. See list of illustrations for index to plates. ; Page Page Akron, Ohio, High Bridge 204 Forth Bridge 187 Alcantara, Spain, Roman Bridge 36 Garabit Viaduct 147 Ancient Period 30 Gaston County, North Carolina, Concrete Bridge (Plate) 259 Avignon, France, Pont St. Benezet ol Geneva, Switzerland, Coulouvrenier Bridge 112 Ayr, Scotland, “The Twa Brigs” a7 Geneva, Switzerland, Pont Butin 207 Barcelona, Spain, Medieval Bridge 56 Glossary of Terms 283 Bascule Bridge 209 Hannibal Bridge over Vulturne, Italy 112 Berea, Ohio, Stone Masonry Arches 114 Harrisburg, Pennsylvania, Concrete Bridge 204. Berne, Switzerland, Arch Bridge over the Aar 148 Harrisburg, Pennsylvania, Masonry Bridge 114 Bhutan, Asia, Old Timber Cantilever Bridge 30 Hartford, Conn., Bridge over Connecticut River 114 Bibliography 282 Haverhill, Massachusetts, Concrete Bridge (Plate) 241 Biddeford, England, Medieval Bridge 08 Heidelberg, The Old Bridge 99 Bonn, Germany, Arch Bridge over the Rhine 148 Herkimer, New York, Concrete Bridge (Plate) 253 Boston, Massachusetts, Longfellow Bridge 149 Kew, England, Edward VII Bridge fitz “Brothers of the Bridge”’ 51 Key Bridge, Washington, District of Columbia 208 Budapest, Hungary, Elizabeth Bridge Awe: Lavaur, France (Plate) 126 _ Budapest, Hungary, Kettenbriicke GR London, England, New London Bridge 99 Caesar’s Bridge over the Rhine 32. London, England, Old London Bridge 52 Cahors, France, Medieval Bridge 52 London, England, Southwark Bridge 145 California, Highway Commission Bridges 208 London, England, Tower Bridge (Plate) 273 Cashmere, Asia, Timber Arch Bridge 30 London, England, Waterloo Bridge 98 Castleton, New York, Bridge over Hudson River 188 London, England, Westminster Bridge 146 Chatellerault, France 85 Luxemburg, Pont Adolphe 111 Chatsworth, England, Park Bridge 83 Lynchburg, Virginia (Plate) 256 Chester, Pennsylvania, Small Memorial Bridge (Plate) 261 Mayence, Germany 188 Chicago, Illinois, Franklin Street Bridge 210 Menai Strait, Wales, Telford’s Bridge 171 Chicago, Illinois, Michigan Avenue Bridge 210 Menai Strait, Wales, Britannia Bridge 107 Chinese Bridges 30 Middle Ages 51 Chung-King, China, Masonry Arch Bridge 30 Minneapolis, Minnesota, Cappelen Bridge 207 Cincinnati, Ohio, Concrete and Brick Bridge (Plate) 255 Modern Era 107 Cleveland, Ohio, Masonry Bridges over Parkway Lis Montauban, France, Medieval Bridge 52 Cleveland, Ohio, Rocky River Bridge 201 Montclair, New Jersey, Small Park Bridge (Plate) 262 Cleveland, Ohio, Concrete Railway Bridges 208 Newburyport, Massachusetts, Old Suspension Bridge 171 Cleveland, Ohio, Steel Arch Bridges 149 New York, New York, Brooklyn Bridge ie Cleveland, Ohio, Hilliard Bridge (Plate) 269 New York, New York, Hell Gate Bridge 148 Cleveland, Ohio, Steel Railway Bridge 188 New York, New York, High Bridge 114 Coalbrookdale Iron Bridge 145 New York, New York, Manhattan Bridge 173 Cologne, Germany, Railway Bridge 188 New York, New York, Queensboro Bridge 187 Cologne, Germany, Steel Arch (Plate) 161 New York, New York, Washington Bridge 147 Cologne, Germany, Suspension Bridge 174 New York, New York, Williamsburg Bridge 173 Columbus, Ohio, King Ave., Third and Broad Street 202 Niagara Falls, New York, Steel Arch Bridge 148 Constantine, Algeria, Arch Bridge 146 Niagara Falls, Ontario, Small Concrete Bridge (Plate) 254 Constantinople, Turkey, Pontoon Bridge Oil Nimes, France, Pont du Gard 35 Dayton, Ohio, Concrete Bridges 205 Opening Bridges 209 Delaware Water Gap Bridge of D., L. & W. R. R. 205 Orense, Spain, Old Bridge over Minho 56 Devil’s Bridges 55 Orleans, France, Railway Bridge 113 Dolceacqua, Italy, Ancient Bridge 56 Orthez, France, Medieval Bridge 51 Eads, J. B. 146 Paine, Tom 108 Eighteenth Century 97 ~~ Palladio 34 Elyria, Ohio, Masonry Arch Bridges 114 Paris, France, Panorama of Bridges 84 Fairmont, W. Va., Bridge over Monongahela River 206 Paris, France, Pont Alexandre III Tit Florence, Italy, Ponte Vecchio 56 Paris, France, Pont au Change 110 Florence, Italy, Ponte Della Trinita 82 Paris, France, Pont de l’Alma 110 [ 287 ] GENERAL TEXT INDEX—Continued Page Paris, France, Pont de la Archeveche 109 Paris, France, Pont de la Concorde 97 Paris, France, Pont Neuf 83 Paris, France, Pont Royal 83 Paris, France, Pont St. Louis 83 Pavia, Italy, Bridge over Ticino at Periods—Historical 21 Perronet (see appendix for biography) 97 Persian Bridges 52 Philadelphia, Pennsylvania, Delaware River Bridge 174 Philadelphia, Pennsylvania, Walnut Lane Bridge 201 Piedmont, Calif., Small Concrete Bridge (Plate) 261 Pile Bridges—Ancient 31 Pisa, Italy, Ponte di Mezzo (Plate) 96 Pisa, Italy, Ponte Solferino 112 Pittsburgh, Pennsylvania, Seventh Avenue Bridge 174 Pittsburgh, Pennsylvania, Sixteenth Street Bridge 149 Pittsburgh, Pennsylvania, Fortieth Street Bridge 149 Plauen, The Frederic August Bridge 111 Pole, Prof. 108 Pontoon Bridges | Prague, Karlsbriicke 56 Pu’to’Shan, China, Masonry Arch Bridge 30 Quebec, Canada, St. Lawrence River Bridge 188 Renaissance Period 82 Rennie (see appendix for biography) 97 Richmond, Virginia, Mayo’s Bridge 204. Rimini, Italy, Ponte di Augusto 35 Riverside, California, Small Concrete Bridge (Plate) 266 Roebling, John A. 172 Robinson, C. M., “Modern Civic Art” 84. Roman Period 34 Rome, Ponte Cavour (Plate) 244 Rome, Ponte Molle 35 Rome, Ponte Quattro Capi 34 Rome, Ponte Rotto 34 Rome, Ponte St. Angelo 30 Rome, Ponte Sisto 34 Rome, Ponte Umberto Rome, Vittorio Emanuele II Bridge (Plate) 245 (Plate) 143 Ronda, Spain Riidesheim, Germany St. Chamas, France, Roman Bridge St. Louis, Missouri, Eads Bridge San Diego, California, Cabrillo Bridge Scarsdale, New York Segovia, Spain, Roman Aqueduct Séjourné Serchio, Italy, Devil’s Bridge Stephenson (see appendix for biography) Sublician Bridge, Rome Sze-Chuan, China, Suspension Bridge Thebes, Illinois, Bridge over the Mississippi Toledo, Ohio, Cherry Street Bridge Toledo, Spain, Puente de Alcantara Toledo, Spain, Puente de San Martin Trajans Bridge over the Danube Tunkhannock, Pa., D., L. & W. R.R. Bridge Types of Bridges Utah, Natural Bridges Venice, Italy, Ponte di Rialto Venice, Italy, Ponte di Sospire Verona, Italy, Ponte della Pietra Verona, Italy, Gastelvecchio Vorailberg, Austria, Masonry Arch Wales, Britannia Bridge Wales, Pont Y Pridd Washington, D. C., Anacostia Bridge Washington, D. C., Arlington Bridge Washington, D. C., Cabin John Arch Washington, D. C., Connecticut Ave. Bridge Washington, D. C., Key Bridge Washington, D. C., Q Street Bridge Whipple Truss Bridges Wilhelmshaven, Germany Willoughby, Ohio Wilmington, Delaware Worms, Germany Zaragossa, Spain, Puente de Piedra Zanesville, Ohio, Timber Bridge [ 288 ] Page (Plate) (Plate) (Plate) 113 148 36 146 207 207 37 113 55 107 31 28 188 202 54 54 33 205 19 22 82 82 57 57 113 107 oo 274 276 114 201 208 206 147 272, 203 206 149 57 115