THE UNIVERSITY OF ILLINOIS LIBRARY 621 . 182 . Io9-f Collection of books written by Members of the Faculty of .the College of Engineering OFFICIAL PUBLICATION OF IOWA STATE COLLEGE OF AGRICULTURE AND MECHANIC ARTS Vol. 15 APRIL 20, 1917 No. 34 LOCOMOTIVE TESTS With Iowa and Illinois Coals BULLETIN 44 ENGINEERING EXPERIMENT STATION Ames, Iowa Published Tri-Monthly by the Iowa State College of Agriculture and Mechanic Arts. Entered as Second-class Matter at the Post Office at Ames, under the Act of Congress of August 24, 1912. STATE BOARD OF EDUCATION Members Hon. D. D. Murphy, President Elkader Hon. Geo. T. Baker Davenport Hon. Chas. R. Brenton Dallas Center Hon. P. K. Holbrook Onawa Hon. Edw. P. Schoentgen Council Bluffs Hon. H. M. Eicher Washington Hon. Frank F. Jones Villisca Hon. Paul Stillman Jefferson Hon. W. C. Stuckslager Lisbon Finance Committee Hon. W. R. Boyd, President Cedar Rapids Hon. Thomas Lambert Sabula Hon. W. H. Gemmill, Secretary Des Moines ENGINEERING EXPERIMENT STATION Station Council (Appointed by the State Board of Education) Raymond A. Pearson, LL. D President Anson Marston, C. E Professor Louis Bevier Spinney, B. M. E Professor Samuel Walker Beyer, B. S., Ph. D Professor Warren H. Meeker, M. E Professor Fred Alan Fish, M. E. in E. E Professor Martin Francis Paul Costelloe, B. S. in C. E., A. E Professor Allen Holmes Kimball, M. S Professor Thomas Harris MacDonald, B. C. E.. .Chief Engineer, Iowa Highway Commission Station Staff Raymond A. Pearson, LL. D President, Ex-Officio Anson Marston, C. E Director and Civil Engineer Charles S. Nichols, C'. E Assistant to Director Louis Bevier Spinney, B. M. E Illuminating Engineer and Physicist Samuel Walker Beyer, B. S., Ph. D Mining Engineer and Geologist Warren H. Meeker, M. E Mechanical Engineer Fred Alan Fish, M. E. in E. E Electrical Engineer Martin Francis Paul Costelloe, B. S. in C. E., A. E Agricultural Ehgineer Allen Holmes Kimball, M. S Structure Design Engineer T. R. Agg, C. E Highway Engineer John Edwin Brindley, A. M., Ph. D Engineering Economist Max Levine, S. B Bacteriologist Roy W. Crum, C. E Structural Engineer Homer F. Staley, M. A Ceramic Engineer D. C. Faber, E. E Industrial Engineer H. W. Wagner, M. E Mechanical and Electrical Engineer John S. Coye, S. B Chemist William J. Schlick, C. E Drainage Engineer Harold F. Clemmer, B. S. in C. E Testing Engineer James W. Bowen, A. B., M. A Assistant Chemist W. G. Whitford Research Fellow in Ceramics A. 0. Smith Mechanician 'UX, b CONTENTS uuu Xe^f po VALUE OF LOCOMOTIVE COAL TESTS 5 SUMMARIZED RESULTS OF TESTS 6 LENGTH OF ECONOMICAL HAUL 8 THE TESTING LABORATORY 11 THE TEST LOCOMOTIVE 15 MEASURING INSTRUMENTS 15 COALS TESTED 15 NOTES ON CONDITIONS DURING TEST RUNS 17 DETAILED RESULTS OF TESTS— Basic Averages and Totals from Readings 19 Calculated Boiler Data 21 Calculated Engine and Brake Data 25 Notes on Individual Results 29 Indicator Cards 31 Group Averages 39 LIST OF TABLES Table I. Testing Plant Data 13 Table II. Locomotive Data 13 Table III. Analyses of Coals by Car Loads 16 Table IV. Moisture Content and Heat Units in Coal by Test Runs 16 Table V. Analyses of Ash and Refuse 17 Table VI. Basic Averages and Totals — By Individual Test Runs 24 Table VII. Calculated Results of Boiler Trials — By Individual Test Runs... 26 Table VIII. Calculated Results of Engine and Brake Data — By Individual Test Runs 28 Table IX. Averages of Readings and Results — By Car Loads of Coal 36 Table X. Averages of Important Readings and Results — By Coals 38 LIST OF ILLUSTRATIONS Fig. 1. Graphic Tabulation of Coal Efficiencies 7 Fig. 2. Illustrative Diagram of a Railroad System 8 Fig. 3. General View of Testing Laboratory 10 Fig. 4. Detail View of Brake with Dynamometer 12 Fig. 5. View of Test Locomotive 14 Fig. 6. Rear of Testing Laboratory 18 Figs. 7 to 14. Indicator Cards 32-35 Fig. 15. Right Hand Brakes 40 Fig. 16. C. & N. W. Locomotive No. 1769 in Testing Position 40 ACKNOWLEDGMENT The coals burned during the tests were supplied by the Chicago & Northwestern Railway Company. Technical assistance and sug- gestions were given by Mr. J. C. Little, Mechanical Engineer, and other officials of the same company. The following members of the Iowa State College staff were en- gaged on different phases of the tests : Professor E. E. King, head of the Railway Engineering Depart- ment, made general arrangements for the work and had general direction of it. Professor R. A. Norman of the Mechanical Engineering Depart- ment made preliminary outline for the technical work and acted as tech- nical advisor during the test runs and preparation of results. Mr. H. W. Wagner of the Engineering Experiment Station had direct charge of readings and preparation of results for publication and was assisted with readings and calculations by Mr. George Smullin, engineering student. Analyses of coal, ash, and flue gas were made by the Chemical Section of the Engineering Experiment Station, under the direction of Mr. J. S. Coye, Chemist. Mr. Chas. Kinderman, assisted by Mr. H. H. Howard, acted as chief mechanician during the test runs. Mr. W. H. Meeker. Professor of Mechanical Engineering and Mr. W. R. Raymond, Associate Professor of English, offered helpful criticism of the manuscript. 5 LOCOMOTIVE TESTS WITH IOWA AND ILLINOIS COALS VALUE OF LOCOMOTIVE COAL TESTS Coal is one of the large items in the expense of railway operation. Not only does its first cost aggregate an enormous sum, but its trans- portation to points of use requires a large amount of equipment and operating service often sorely needed for heavy seasonal commercial freightage. Even though the first cost of coal at the mine may be re- duced to a minimum by advantageous contracts with large coal com- panies and by other measures of economy, the final cost will also depend upon the cost of transportation. It is for this reason that railway companies are interested in knowing just where lies the economical limit of haul between any two coal fields, i. e., how far they can haul the locomotive coal from one mine until it becomes cheaper to use that from the next. The costs of locomotive coals per unit of power output do not depend alone upon the prices per ton at the mine, the ton-miles charged for in transportation, and the expenses per ton for handling; in addi- tion to these there must be considered the relative values per ton of the coals as producers of power. Operating records will show the former costs, but the relative power producing values of coals can be deter- mined only by scientific tests under operating conditions. This problem confronts many if not all of the trunk line railroads crossing Iowa, and involves not only a comparison of Iowa coals with those from other states, but also a comparison of coals from different Iowa fields. Thus it is to assist in the solution of this problem for the railroads of Iowa that the Engineering Division of the Iowa State College has begun a series of tests in its new Transportation Labora- tory, in co-operation with the Iowa railway companies. The first group of tests, here reported, was in co-operation with the Chicago & Northwestern Railway Company, to aid in determining just how far they can afford to haul their coal from the Benld, Macoupin County, Illinois, mine toward their Buxton No. 18, Monroe County, Iowa, mine. The coals from both mines were compared by running a number of locomotive efficiency tests and by studying the firing and steaming properties. The coal was burned in a locomotive provided two years ago by the Chicago & Northwestern Railway Company for labora- tory testing purposes. 6 SUMMARIZED RESULTS OF TESTS Since the primary object of this investigation was to determine relative values of Iowa and Illinois coals under certain prescribed conditions, the following summary is confined largely to comparisons between these two fuels. Proximate and calorific analyses show but little difference on a dry basis. The Iowa coal, however, contained more moisture than the Illinois coal. Consequently, as received, it contained less heat units per pound than did the Illinois coal. Little important difference was apparent in the firebox. Smoke was noticeably thinner, however, after the same fireman changed from Illinois to the first carload of Iowa coal. Longer test runs would have told more concerning the clinkering tendencies of ash from the two coals. It was observed, however, that Iowa coal at the end of a run left a clinker more difficult to remove than that from Illinois coal. Pounds of ash and refuse were higher, with a lower percentage of carbon, for runs with Illinois coal. This comparison is, however, of little definite value because of the difficulty of securing representative amounts. Boiler and grate efficiency was decidedly higher with Iowa than with Illinois coal. According to Table X, the advantage by difference is 5.1% and by percentage, 8.7%. All averages of other factors of boiler and engine performance based upon coal fired show the more favorable results with Iowa coal. According to Table X, the advantage in coal, as fired, per estimated draw-bar horse-power-hour is 0.54 pound, or 7.0% less Iowa than Illinois coal. The advantage in plant efficiency, from coal to draw-bar power by difference is 0.38% and by percentage, 11.6% higher for Iowa than for Illinois coal. It does not seem plausible that the higher average boiler and grate efficiency with Iowa coal would be due to more favorable conditions existing during trials on Iowa coals than those on Illinois coals. The furnace and flues were reasonably clean when the trials began. They were cleaned just before Run No. 6, yet the efficiency of Runs 6 and 7 average practically the same as for Runs 1 to 5. The first 7 runs were all with Illinois coal. Runs 8 to 1 1 on Iowa coal were made directly after Runs 1 to 7 and with the same fireman. The average boiler and grate efficiency for Runs 1 to 7 was 58.9% and for Runs 8, 9, 11 and 18 was 65.1%. Average of the same item for Runs 19 to 22 with a different fireman, on Iowa coal, was 62.9%. The average load carried was greater with Illinois than with Iowa coal ; but in Runs 8, 9, 11 and 18 on Iowa coal the average load was higher and the efficiency was also higher than in Runs 19 to 22 on Iowa coal. lust how far the results of these trials would go towards repetition in locomotives of other types cannot be foretold. But it is the opinion of able engineers consulted on the subject that the same Equivalent Evaporation (2/2°E) perFbund Coal as Fired. 0 / 8 SO 8 -J s I 1 z 3 ¥ 6 6 \ • 7 I /§ 8 Q; 9 a 18 19 ZO Zt \ zz 5 ■* j & i Average for Iowa Coal 0 100 ZOO 300 ¥00 500 Boiler Horse Power Developed. Average for Illinois Cool. FIG. 1. n f Cl .bg QQ £ $S. '§£ g* 2 k/ ^ I'S * M vj • Graphic Tabulation of Coal Efficiencies by Runs. Efficiencies are expressed in terms of pounds of equivalent evaporation from and at 212° F. per pound of coal as fired. The white area under each black bar represents the average boiler horse power during the same run. 8 general comparisons would hold for larger and more modern loco- motives. The evaporation per pound of coal and the boiler horse power developed, by separate runs and by averages, are presented in graphic form in Fig. 1. Knowing the evaporative powers of certain coals (as for example the averages pictured in Fig. 1) and certain com- mercial factors, the most economical length of haul for each coal can be determined approximately by means of a simple formula. Such a formula is developed under the next heading. LENGTH OF ECONOMICAL HAUL As already suggested the object of this investigation is to help determine where the economical limit of haul lies between the coal of one held and that of another. Following up this idea, an algebraic formula is derived which solves the distance between the point of economical division and either of two mines, provided certain condi- tions are known. FIG. 2. Illustrative Diagram of a Railroad System with Two Coal Fields. Referring to Fig. 2, Bj G D E Aj represents the main line of a railroad. Coal from mine A reaches the main line at the point A ± and coal from mine B reaches the main line at the point B^ The point of economical division is assumed to be at D ; that is, it will be most economical to use coal from mine A between A and D, and coal from mine B between B and D. The distance between A 1 and D is repre- sented by x miles and is to be solved for. The cost of mining and loading coal varies between mines: the cost of freight per ton per mile (per ton-mile) also varies on different branch lines. Consequently the following derivation depends upon a knowledge of the total costs per ton of coal from mine A and mine B delivered at A t and B u respectively. The distance n, between A, and B x , is easily found. The total cost per ton-mile of handling the coal between points A x and B x must also be known. It is assumed to be constant for hauling in either direction and for either coal, and 9 includes switching, hauling, unloading at the chutes, etc. Tons of equivalent evaporation per ton of coal from mines A and B are repre- sented by E a and E b , respectively, and are determined by test. For the coals used in this particular investigation, item 57, Table X, gives the numerical values for E a and E b . The algebraic work follows: Given : a = total cost per ton of coal delivered at junction point Aj from mine A. b = total cost per ton of coal delivered at junction point from mine B. f = cost of freight and handling per ton-mile for coal between points A t and B^ E a =tons of equivalent, evaporation from and at 212° F. per ton of coal from mine A. E b =tons of equivalent evaporation from and at 212° F. per ton of coal from mine B. Assume : D is the point, between points A x and B t , at which the total cost of coal for a unit of evaporation is the same for coals from mines A and B. x = distance between points A t and D. C d =cost of either coal (delivered at the point D) required for one ton of equivalent evaporation from and at 212° F. Then : C d = c d = a -f- xf Ea a + xf E a b + (n-x)f 'E, - _ b-f (n-x)f E b and then Solving for x : aE b -f- xfE b = bE a nfE a — xfE a . bE a + nfE a — aE b or X ~ fE b + fE a E a (b + nf) — aE b X_ f(E a +E b ) ' Units of costs used above may be expressed in either dollars or cents, but the same unit must be used throughout all computations. In case f is constant for the main line A^i and for the branches AA t and BB^ n may be taken as the distance AA^B and x as the distance AA X D, if a is used as the cost at A and b as the cost at B. For the branch line EF which must receive coal through the junc- tion point E, it would be more economical to use coal from mine A, since E is between A t and D. Likewise it would be more economical to use coal from mine B on the branch line GH. 10 General Interior View of the Iowa State College Locomotive Testing Laboratory. The feed water weighing tanks and reservoir are in the left background. The dynamometer pedestal is shown under the firing platform. 1 ne sup- port wheels and brakes are in the pit below the level of the track. li The above formula is comparatively simple and does not take into account certain minor factors which may affect the economical limit of haul. For instance, a coal which clinkers worse than another will not stand so high in absolute value as is indicated by comparative evaporative powers of the two coals. Or the general grade may be steeper in one direction on the main line, which would tend to move the point D farther down grade. However, the actual location of point D is often determined in practice by the convenience of existing traffic and the location of unloading stations. The formula will, then, serve as a general check on the point of economical division. THE TESTING LABORATORY The testing laboratory, as pictured in Figs. 3 and 6, is entirely modern and of sufficient size and capacity to accommodate the largest Mikado locomotives. While it is planned ultimately to equip the plant with a 125,000-lb. capacity dynamometer for measuring directly the draw-bar pull of the locomotives, as yet only the pedestal has been in- stalled ; to this the engine is tied by a heavy draw-bar and two safety bars, all fitted with turnbuckles. Until the large capacity dynamometer is provided, the approximate draw-bar pull is determined by spring dyna- mometers connected to the water brake casings. When the locomotive is in testing position, each driving wheel rests upon a support wheel. Directly opposite each other, the support wheels are shrunk to the same shaft or axle. For each pair of support wheels there are provided two Alden triple disc water brakes of sufficient capacity to absorb the energy from the drivers of the largest locomotives. Each brake has three iron discs which are fastened to the axle and which revolve with it. Each iron disc turns between a separate pair of comparatively flexible copper diaphragms whose perimeters are clamped into an outer casing which is held from turning by a Kohlbusch spring dynamometer of 6,000-lb. capacity. See Figs. 4 and 15. The support wheels arjd axles were given to the Iowa State College by the Midvale Steel Company of Philadelphia. Each dynamometer measures the rotative pull on the brake in the same way as do the scales of a Prony brake. So from the sum of all the brake readings is figured the draw-bar pull. Then with the addi- tion of speed readings, the draw-bar horse power is calculated. The draw-bar pull is varied by changing the friction between brake discs and diaphragms. This friction is controlled by the pressure of water which circulates between the copper diaphragms and which carries away the heat developed by friction from mechanical power. Friction surfaces are lubricated by oil under pressure. In applying the water pressure to these brakes it is arranged to control them all at a central valve pit located to the rear of the engine, or to regulate each one individually. But owing to the difficulty of knowing the load on the wheels when operating from the valve pit, it was found 12 FIG. 4. Detail View of Alden Hydraulic Brake with Kohlbusch Spring - Dynamo- meter. Water inlet is at the lower hose connection and the water outlet is at the upper hose connection. The smaller pipes are for oil supply and drainage. 13 necessary to control each pressure at the brake where the load on each individual dynamometer could be readily observed. Hand control valves in both the inlet and outlet pipes make it possible to regulate not only the pressure but also the quantity of cooling water through the brakes. It is not intended to give here a detailed description of the testing plant, but Table I is included to show a few dimensions and other data which bear directly upon the test results. TABLE I TESTING PLANT DATA Number of feed water weighing - tanks 2 Capacity of each feed water weighing tank, gallons 340 Capacity of coal weighing scales, lb 3,500 Maximum draw-bar pull for which dynamometer pedestal is designed, lb... 125, 000 Number of support wheels 8 Number of support wheels used for runs 1-22 4 Diameter of support wheels, inches 52 Length of brake arm. inches 26 A Capacity of each brake dynamometer, lb 6,000 TABLE II LOCOMOTIVE DATA Railway Type Class Number Weight of engine in working order, lb Weight on drivers, lb Weight on truck, lb Theoretical tractive force, lb. Number of driving wheels Driving wheel diameter, in Cylinder diameter, right side, in Cylinder diameter, left side, in Diameter of right piston rod, in Diameter of left piston rod, in Length of stroke, in Engine horse power constant, right, crank end ... Engine horse power constant, right, head end . . . Engine horse power constant, left, crank end .... Engine horse power constant, left, head end Greatest travel of valve, in Outside lap of valve, in Exhaust lap, in Lead, in Nominal boiler pressure, lb. per sq. in Diameter of boiler at first ring, in Number of boiler fire tubes Diameter of fire tubes, in Length of fire tubes, ft Heating surface (fire tubes), sq. ft Heating surface (fire box), sq. ft Heating surface (water tubes), sq. ft Heating surface (total), sq. ft Grate area, sq. ft Diameter of exhaust nozzle, in C. & N. W. . . American B-3 258 78,000 50,000 28,000 13,650 . .59.64 . . 17 rs . .16 ft ■ . .2 ff 2 '» 24 0.01411 0.01446 0.01336 0.01370 5 Vs . . . . . A o 135 50 151 2 . .11.67 . .835.0 . .119.8 . . 9.8 . .964.6 . . 17.5 . .3.625 14 View of C. & N. W. Locomotive No. 258 in Testing Position, and Testing Crew. 15 THE TEST LOCOMOTIVE The locomotive used for all test runs was provided by the Chicago & Northwestern Railway Company in 1914, an American type engine which until that time had been used in both passenger and freight service on one of the Dakota divisions. It had received a light over- hauling just before coming to the College, and was therefore in fairly good repair. A photographic view of the locomotive is shown in Fig. 5. Table II contains dimensions and other data concerning it. MEASURING INSTRUMENTS Sargent laboratory thermometers were used for taking all tempera- tures except that in the smoke box. Special pyrometers were em- ployed for determining the smoke box temperatures. (See item 13, page 20.) The Orsat apparatus was used for analyzing flue gas. This apparatus has three absorption pipettes : the first contains a solution of caustic potash and absorbs C0 2 ; the second contains a solution of caustic potash and pyrogallic acid and absorbs oxygen ; and the third contains a solution of cuprous chloride and absorbs CO. The Parr bomb calorimeter was employed for determining the B.t.u. content of the coals. Indicator cards were taken with Crosby outside spring indicators equipped with 120-pound springs and continuous drum attachments. The dome steam gage, pyrometers, coal and water scales, brake dynamometers, revolution counters, and indicator springs were checked or calibrated especially for the test runs. The more simple instruments not mentioned above are described in the detailed results of the test runs. COALS TESTED Only two types of coal were tested during this investigation. Both coals are being burned in Chicago & Northwestern locomotives in regular service; one is an Iowa coal from Buxton mine No. 18, Monroe County ; the other is an Illinois coal from the Benld mine, Macoupin County. Runs 1 to 7 were made with a car (No. 1) of the Illinois coal ; Runs 8 to 11 and Run 18 with a car (No. 2) of the Iowa coal; and Runs 19 to 22 with a second car (No. 3) of the Iowa coal. The coal in all three cars was of lump size, though some of the larger lumps were broken up just before firing. The average size of the Iowa coal, Cars Nos. 2 and 3, was somewhat larger than that of the Illinois coal, and contained a less amount of fine material. Although rain fell during the latter part of Run 9, it added very little moisture to the coal burned in that run. Coal for Run 11, how- ever, contained some moisture from the rain. 16 TABLE III ANALYSES OF COALS BY CAR LOADS Name of coal County Mine Car No Nos. of test runs Illinois Macoupin Benld 1-7 Iowa Monroe Buxton No. 18 2 8-11, 18 Iowa Monroe Buxton No. 18 3 19-22 Average proximate analysis, coal as received Moisture, per cent 13.4 16.2 15.6 Volatile matter, per cent 33.9 | 33.3 33.0 Fixed carbon, per cent 37.8 34.9 37.6 Ash, per cent 14.9 15.6 13.8 Total, per cent . 100.0 100.0 100.0 Sulfur, per cent 4.8 5.5 4.3 Average B. t. u. per pound As received 10,030 9,350 9,930 Moisture free 11,580 11,160 11,760 Combustible 14,000 13,700 14,060 TABLE IV MOISTURE CONTENT AND HEAT UNITS IN COAL BY TEST RUNS Name of Coal Mine Car No. Run No. Coal as Received Moisture, % B. t. u. 1 per pound Illinois Benld, 1 1 14.9 9,860 Macoupin 2 13.8 9,980 County 3 13.8 9,980 4 13.0 10,080 5 13.0 10,080 6 12.6 10,110 7 12.6 10,110 Iowa Buxton 2 8 17.1 9,250 No. 18, 9 17.1 9,250 Monroe 11 16.3 9,340 County 18 14.4 9,550 Iowa Buxton 19 16.7 9,800 No. 18, 20 16.7 9,800 Monroe j 3 21 14.4 10,070 County 22 14.4 10,070 A small representative sample of coal was chosen from each cart load as it was weighed for firing. If but one run on a certain car of coal was made in a day, the total sample from each run was broken up, mixed, and quartered, and a small portion kept for analysis. If two runs were made in one day on a certain car load, samples from both runs were mixed together, broken up, and quartered for the sample for analysis. The percentage of moisture was determined on each analysis sample so obtained. Then all samples from one car load of coal were mixed together and this composite sample was analyzed for volatile matter, fixed carbon, ash, sulfur, and heat units. The results of these 17 analyses appear in Tables III and IV. In Table III the percentage of moisture is based upon determinations for the separate days; all other items are based upon analyses of composite samples. Table IV gives the moisture content for runs made on separate days, as well as the B.t.u. content per pound as received. Corrected for moisture in the corresponding samples. TABLE V ANALYSES OF ASH AND REFUSE N ame of Coal ! Mine Car No. Run No. As Received Moisture Free Total Pounds From Test Run Moisture % Carbon % Carbon % Ash and Refuse Carbo n Illinois Benld, 1 1 7.3 19.2 20.6 245 47 Macoupin 2 3.8 16.1 16.7 254 41 County 3 3.8 16.1 16.7 272 44 4 3.6 17.8 18.4 407 72 5 3.6 17.8 18.4 378 67 6 2.7 16.6 17.1 343 57 7 2.7 16.6 17.1 347 58 Iowa Buxton 2 8 4.2 26.5 27.7 1 258 68 No. 18, 9 4.2 26.5 27.7 465 123 ! Monroe 11 1 .4 13.8 14.0 315 43 County 18 1 .0 20.7 20.9 210 43 Iowa Buxton 3 19 0.6 23.0 23.2 225 52 No. 18, 20 0.6 23.0 23.2 220 51 Monroe 21 4.0 26.1 27.2 160 42 County 22 4.0 26.1 27.2 225 59 In Table V will be found the carbon content and other data per- taining to the ash and refuse. NOTES ON CONDITIONS DURING TEST RUNS In order to secure representative averages and to determine the reliability of individual runs as compared with the corresponding aver- age, a considerable number of test runs were made on each coal under the same prescribed conditions. Steam pressure, cut-off, speed, and draw-bar pull were kept as nearly as possible the same for all runs. During the preliminary work it was decided to set the reverse lever 8 notches ahead of center position. The throttle opening was adjusted until a suitable speed was attained, after which the position of the throttle lever was marked. Each engineer-fireman was then instructed to keep the reverse and throttle levers in these same positions for all runs. Also the man at each brake regulated the water pressure on his brake wheel so as to hold the brake dynamometer pointer as constant as possible on 1,500 pounds during all runs. In all, 22 test runs were made, but 7 of these are not included in the report. The furnace and boiler were not in condition to give normal results during Runs 12 to 17. Run 10 is also omitted because efficiencies calculated from readings during this run were so high as to indicate a possible error in the weight records. 18 FIG. 6. Rear of Testing Laboratory. Valve control pit is shown in the center back- ground. Since the engineer-fireman who served for Runs 1 to 11 could not be retained after Run 11, Runs 18 to 22 were made with another fire- man. This fact makes a direct comparison between certain runs somewhat unreliable because of different methods of firing used by different firemen. The engineer-fireman was in each case a locomotive engineer and an employee of the Chicago & Northwestern Railway, and he was allowed to follow his own system of firing. During Runs 1 to 11 coal was usually fired one shovelful at a time, about seven shovels in five minutes. The average weight per shovel was then about twenty- five pounds. During Runs 18 to 22 coal was usually fired two, three or four shovelfuls at a time, but the average weight per shovel was less than during Runs 1 to 11. Since the locomotive had been working satisfactorily before Run 1 was started, the furnace and boiler parts were not especially cleaned for that run. The diaphragm plate was removed from the smoke box just before Run 2. The boiler flues were cleaned between Runs 5 and 6; it was noted that the seven bottom flues were dirty. The back flue sheet and flues were cleaned just before Run 18, and a new furnace arch of foundry brick was built. 19 The back flue sheet was cleaned of “honey-comb” and the arch was replaced with Chicago & Northwestern brick between Runs 18 and 19. The back flue sheet was examined and found to be reasonably clean after Run 21 and was not cleaned again. The front ash pan damper was closed some of the time and was partly open some of the time during the various runs. Its relative opening is shown roughly by the ash pan draft, item 6, Table VI. As no provision has yet been made to determine the loss by sparks and cinders that go through the stack, the smoke and exhaust steam were discharged directly into a pipe through the roof. From the College mains the boiler feed water was run into the weighing tanks, and then into the feed water reservoir. As the water used was very hard, regulation quantities Of soda ash were added to each tank of water. DETAILED RESULTS OF TESTS Basic Averages and Totals from Readings. The chief observer and his assistant each carried, during the run, a special typewritten data blank, made up for the log of test readings. These two observers took all routine original readings except on weight of coal, weight of feed water, temperature of feed water, flue gas analysis, and coal and ash analysis ; these latter readings were taken by men who performed the corresponding details of the work, and who later reported to the chief observer. Most routine readings were taken at 10-minute intervals during the test runs ; coal and feed water were weighed out as required, and indicator cards and flue gas analyses were generally made at 20- minute intervals. Following are descriptions of readings with item numbers corre- sponding to those in Tables VI, IX and X. Item 4. Boiler Gage Pressure : Read from the cab gage (uncali- brated) and from a calibrated gage on the dome. The latter reading is used in the calculations. Item 5. Barometer: Reading taken at noon from a mercury barome- ter in the College Steam and Gas Laboratory Building and used for all runs during the day, Item 6. Ash Pan Draft: Read on an Ellison differential draft gage. Item 7. Smoke Box Draft: Read on a water “U” tube gage connected to the smoke box back of the diaphragm. Item 8. Smoke Box Draft, Front: Read on a water “U” tube gage connected to the smoke box ahead of the diaphragm. Item p and 10. Temperatures of Outdoor and Engine Room Air: Taken from laboratory thermometers hung in the shade outside and inside the building. Item 11. Temperature of Feed Water: Taken from a laboratory thermometer hung in the feed water reservoir. 20 Item 12. Temperature in Dome Calorimeter: Taken from a labora- tory thermometer set in the oil well of an externally lagged throttling cal- orimeter connected to the steam dome. Item 13. Temperature in Smoke Box: Taken from an expanding stem Tagliabue pyrometer checked by readings from a Brown electric record- ing pyrometer. The stem of the Tagliabue pyrometer and the thermo- couple of the Brown pyrometer were both inserted to measure the tempera- ture at about the center of the smoke box, ahead of the diaphragm. Items 14, 13 and 16. Flue Gas Analysis: Made by the Chemical Sec- tion of the Engineering Experiment Station by means of an Orsat ap- paratus. Each sample of gas was drawn from a sample tube inserted in the lower front part of the smoke box. The first part of the sample was wasted in order to eliminate fresh air and unrepresentative gases which might have collected in the sample tube. Item 17. Pounds of Coal: The coal was weighed out by cart loads on platform scales before being dumped on firing platform. At the start of the run the condition of the fire was noted and firing of weighed coal was begun. Firing was conducted so as to have the fire box contain at the end of the run approximately the same amount of unconsumed fuel as at the start. The weight of any weighed but unfired coal at the end of the run was deducted from the total net weights. Item 18. Pounds of Feed Water: The feed water was weighed out in two stationary tanks, each resting on platform scales, before being dumped into the feed water reservoir. At the beginning of run the water levels in locomotive boiler and in feed water reservoir were noted. The boiler water was brought up to its original level at the end of the run, after which enough water was let out of one of the weighing tanks to bring the water in the feed water reservoir up to the same level as at the beginning of the run. Overflow from the boiler injector was caught and its weight was deducted from the weighed pounds of feed water. Item 19. Total Pounds Ash and Refuse: The ash and refuse were weighed on platform scales. Just before the start of run, the fire was shaken down, after which the ash pan was cleaned. At the end of the run the fire was shaken down to represent, approximately, conditions at the start of the run. The net weight of ash and refuse passed through the grates after the beginning of the run was then recorded. These weights varied much among individual runs, partly because of the lack of uniformity in treating the fire and partly because of the difficulty of shaking down representative amounts during and at the end of the run. Items 20 to 23. Brake Loads : Measured by Kohlbusch spring dyna- mometers, one attached to each brake. All dynamometers were calibrated before the test runs and were read to the nearest 10 pounds during the tests. Item 24. Total Brake Load: Is the sum of the values of items 20 to 23, and represents the total pull of all brakes at the radius of application of the dynamometers. This radius was the same for all brakes. See Table 1. ' 21 Item 23. Driver r. p. m.: Calculated from readings from a revolu- tion counter attached permanently to motion from the right hand engine cross head. Item 26. Brake r. p. m. : Calculated from readings from a revolution counter attached permanently to the axle of the left front support wheel. There were times when either the driver or brake revolution counter was not working. For such times, both speeds were calculated from read- ings from the counter which was working properly. When both coun- ters were working properly, the ratio of the two speeds was found to be quite constant. A hand speed-indicator was also used to check the revolution counters. Calculated Boiler Data. In Tables VII, IX, and X, items 27-73 all refer to boiler and furnace results. Conventional formulas and con- stants were employed for the calculation of practically all of these results. Methods of calculating the more simple items are indicated by the titles. Other items are explained as follows : Items 28, 29, 31, 32, 34 and 33, pounds of coal per hour per square foot of grate and per square foot of heating surface , are based upon dimensions given in Table II. Item 30, pounds of dry coal per hour, has the same value as item 27, with deduction for moisture according to Table IV. Item 33, pounds of combustible coal per hour, has the same value as item 27, with deduction for moisture and ash according to Tables III and IV. Items 36, 39, 40 and 48, all give B.t.u. in thousands. To get the actual value of any of these respective items, multiply the value. given by 1,000. Item 3 7, pounds combustible “consumed” per hour, has the same value as item 33, minus pounds of carbon in ash and refuse according to Table V. Item 39, B.t.u. in ash and refuse, is arrived at by assuming 14,500 B.t.u. per pound of carbon in ash and refuse. Item 40, B.t.u. in combustible “consumed” per hour, is equal to the value of item 36 minus the value of item 39. Item 41, pounds supplied boiler per hour, is the net weight of boiler feed water. Item 42, quality of steam, is calculated from the following formula: x = H — Q + 0.48 (T' — T) . x = quality of steam. Q = heat of the liquid at boiler pressure. L = latent heat of evaporation at boiler pressure. H = total heat in steam at calorimetric or atmospheric pressure. 0.48 = specific heat of superheated steam. T' = temperature in calorimeter. T = temperature of evaporation at calorimetric or atmospheric pres- sure. Pound-Fahrenheit units only are involved in the above formula. 22 Item 43, moisture in steam, is equal to 100% minus the value of item 42. Item 44, pounds dry steam per hour, has the same value as item 41, minus moisture as computed from item 43. Item 43, factor of evaporation, is figured by the following formula : H— (t — 32). F e = l F e = factor of evaporation. H = total heat in steam at boiler pressure. t = temperature of boiler feed water. L = 970.4, latent heat of evaporation at 212 0 F. Pound-Fahrenheit units only are involved in the above formula. Item 46, pounds of equivalent evaporation from and at 212 0 F. per hour, is equal to item 44 times item 45. Item 4 7, equivalent evaporation per hour per square foot of heating surface, is based upon the total heating surface as given in Table II. Item 48, B.t.u. absorbed per hour by dry steam, is equal to the value of item 46 times 970.4. Item 60 , boiler efficiency, is equal to item 48 divided by item 40. Item 61, boiler and grate efficiency, is equal to item 48 divided by item 36. Item 62, boiler horse power developed, is equal to the value of item 46 divided by 34.5. Item 63, total per cent of CO 2, 0 and CO, is the sum of the values of items 14, 15 and 16. All these percentages are used in terms of volumes. Item 64, per cent of nitrogen, is equal to 100% minus the value of item 63. Item 63, ratio of oxygen supplied to that used, is derived from the following formula : N N — (3.8 X O) r == ratio. N = per cent of nitrogen (item 64). O — per cent of oxygen (item 15). 3.8 = ratio of nitrogen to oxygen by volume in fresh air. Item 66, pounds of air per pound carbon, is equal to the value of item 65 times 11. 6. The factor, 11.6, is the approximate number of pounds of fresh air required to burn one pound of carbon. The same excess of air is assumed for all combustible elements in the fuel. Items 63-33, boiler balance sheet, show by approximate percentages what disposition is made of the heat units originally contained in the coal fired. Item 63, heating and evaporating water, is the boiler and grate effi- ciency (item 61). Item 68, heat lost in flue gases, is calculated by the following formula : H f = G X (T g — T a ) X 0.24 X (100%. — L a ) -f- 14,500. H f = percentage of heat in carbon carried out by the gases. 23 G = pounds of gas per pound carbon, or the value of item 66 plus i pound. T g = temperature (°F) of flue gases (item 13). T a = temperature (°F) of engine room air (item 10). L a = per cent of loss in ash and refuse (item 71). 0.24 = specific heat of gases. 14,500 = B.t.u. per pound of carbon. The formula used for item 68 is adapted from the general method used by Kent, Gebhardt, and other authorities. Their method is based upon an ultimate analysis of the fuel and calculates the heat carried out by excess air and by gases resulting from combustion of carbon and hydrogen. While the value of item 68 is reported as applying in general to all stack gases, the method of calculation is correct only as applied to air allowed for burning carbon and to products of this combustion. Its value is higher than the percentage of heat actually carried out by dry gases, but lower than would have been obtained by a computation based upon an ultimate fuel analysis. Such a computation would have added the per- centage of heat carried out by the water of combustion from hydrogen. Item 69, heat lost by moisture in coal, is calculated by the following formula : H m =M Xq-f-h. H m = heat lost by moisture. M = percentage of moisture in coal as fired, h = B.t.u. per pound of coal as fired. q = B.t.u. loss per pound of moisture in coal = (212 — T a ) -j- 970.4 + 0.48 (T g — 21 2). T a = temperature (°F) of engine room air (item 10). 970.4 = latent heat of vaporization at 212 0 F. 0.48 = specific heat of superheated steam. T g = temperature (°F) of flue gases (item 13). Item 70, heat lost in CO, is calculated by the following formula: co C 0 2 + CO ^ 14,500 H co = heat lost in CO. CO = percentage of CO (item 16). C 0 2 = percentage of C 0 2 (item 14). 10,150 = B.t.u. lost by one pound of carbon burning to. CO instead of to C 0 2 . 14,500 = B.t.u. per pound of carbon, burning to C 0 2 . The value of item 70, refers actually only to the carbon in the fuel, but since no ultimate fuel analysis was available and since the difference is slight, the value is reported as referred to all combustible in the fuel. Item 71, heat lost in ash and refuse, is equal to item 39 divided by item 36. Item 72, heat lost and unaccounted for, is equal to 100% minus the sum of the values of items 67 to 71. BY INDIVIDUAL TEST RUNS 24 Item No. CONOO 05 o 1 -H CM CO 17 18 19 CO 22 4-1 2.50 126.90 29.07 Oil 4.30 7.60 ssssg 11.4 6.5 0.0 5,160 27,085 225 1,482 1,535 1,567 1,647 6,231 90.8 104.0 O 21 4-1 2.50 126.80 29.08 OWN 50 58 51 264 770 0 0 f 9 Z U 4,855 26,113 160 1,488 1,546 1,546 1,663 6,243 89.8 102.8 1 20 3-31 2.50 127.70 29.07 0.14 3.90 6.90 49 59 51 261 769 12.0 4.9 0.1 4,856 26,022 220 1,493 1,535 1,546 1,653 6,227 90.0 103.1 19 3-31 2.50 126.70 29.10 0.17 3.40 6.50 45 61 55 264 760 CiOH © co o 4,463 25,567 225 1,496 1,542 1,550 1,624 6,212 89.3 102.3 CM O* 18 3-30 2.50 129.50 29.10 0.13 4.60 8.60 N- CO ^ N» rf CM kO O 5,540 31,346 210 1,500 1,508 1,550 1,638 6,196 95.8 109.7 S 11 3-25 2.50 126.10 28.83 0.06 4.80 7.40 40 56 51 258 795 OICO 5,155 27,027 315 §lj§g§ 88.4 101.4 1 *.s *3« 126.10 28.64 0.07 3.90 7.10 62 74 52 267 788 CO CM O CO o 5,398 29,113 465 l|s|| 93.5 107.1 8 3-24 2.50 126.60 28.62 0.08 3.40 6.80 ^ CO CM OO 00 O 5,337 26,401 258 1,514 1,560 1,547 1,731 6,352 94.8 108.6 7 3-23 2.50 125.80 28.86 0.08 4.20 7.00 45 59 51 265 788 05 CO CM O5t^o 5,118 27,226; 347 §!!!!. 92.9 106.3 6 3-23 2.50 129.00 28.98 0.07 3.90 7.10 35 54 51 261 783 ro YL 66 5,558 27,894 343 1,494 1,519 1,575 1,687 6,275 co oo o 55 5 3-22 2.50 125.90 29.10 0.08 4.20 7.70 33 54 49 259 820 N- N» CM HlOO 11s “ i 8 mm 97.1 111.3 4 3-22 2.50 133.20 28.97 0.08 4.20 8.40 CO ^ CM ONO 6,433 30,496 407 1,515 1,579 1,525 1,712 6,331 98.9 113.4 i 3 3-21 2.50 130.90 28.51 o ^ oo ssssg 9.1 9.8 0.2 5,535 28,341 272 1,518 1,562 1,551 1,691 6,322 93.6 107.2 2 3-21 1.75 §8 0.18 4.60 8.10 3SS|2 12.0 5.3 | 0.1 1 3,815 20,995 254 1,514 1,605 1,540 1,658 6,317 93.8 107.4 ^CO 8888 fc S :il«^g sa :«SSSS§ 22 CO CO gj 34.6 33.9 39.800 17.55 17.551 297.0 6,610 309.4 8.32 7.24 39.4 38.6 83.800 45,400 6.40 87.6 3.04 3 54 59 73 76 71 80 91 98 340 6.51 5.61 65 non 33.3 32.7 38,400 16.61 16.59 280.5 6,600 292.0 7.58 6.53 38.8 38.1 75.700 44.700 6.63 85.9 3.36 :ggg SSS£83 ssl^®! ^ «§-H 28^oo|| 2„S3 |«*| ^ssjti 235 aa.^gg a-a S«8 l '«S5S5s3 eog§c ° 5<8 c < i < m §§ 8 8 15* ■“r >© 88t^oog§ Eco8 ^8 ^StsgJ* °£~ « 88; f2888! • 8ooo8 8S iisaj 22 IN 2 'S' ©