s COp ll =1====================================== BULLETIN OF ILLINOIS COAL MINING INVESTIGATIONS CO-OPERATIVE AGREEMENT Issued bi-monthly VOL. I May, 1915 No. 7 State Geological Survey Department of Mining Engineering, University of Illinois U. S. Bureau of Mines BULLETIN 12 Coal Mining Practice IN District IV BY S. O. ANDROS (Field Work by S. O. Andros. C. M. Young, and J. J. Rutladee) Published by University of Illinois Urbana, Illinois [Entered as second-class matter June 1, 1914, at the Post Office at Urbana, 111., under the Act of Aug. 24, 1914.] The Forty-seventh General Assembly of the State of Illinois, with a view of conserving the lives of the mine workers and the mineral resources of the State, authorized an investigation of the coal resources and mining practices of Illinois by the Depart- ment of Mining Engineering of the University of Illinois and the State Geological Survey in co-operation with the United States Bureau of Mines. A co-operative agreement was approved by the Secretary of the Interior and by representatives of the State of Illinois. The direction of this investigation is vested in the Director of the United States Bureau of Mines, the Director of the State Geological Survey, and the Head of the Department of Mining Engineering, University of Illinois, who jointly determine the methods to be employed in the conduct of the work and exercise general editorial supervision over the publication of the results, but each party to the agreement directs the work of its agents in carrying on the investigation thus mutually agreed on. The reports of the investigation are issued in the form of bulletins, either by the State Geological Survey, the Depart- ment of Mining Engineering, University of Illinois, or the United States Bureau of Mines. For copies of the bulletins issued by the State and for information about the work, address Coal Mining Investigations, University of Illinois, Urbana, 111. For bulletins issued by the United States Bureau of Mines, ad- dress Director, United States Bureau of Mines, Washington, D. C. 3 3051 00006 3580 ILLINOIS COAL MINING INVESTIGATIONS CO-OPERATIVE AGREEMENT Issued bi-monthly State Geological Survey Department of Mining Engineering, University of Illinois U. S. Bureau of Mines BULLETIN 12 Coal Mining Practice IN District IV BY S. O. ANDROS (Field Work by S. O. Andros, C. M. Young and J. J. Rutledee) Urbana University of Illinois 1915 1915 CONTENTS PAGE Introduction 7 Description of coal scam 15 Mining practice 19 Ventilation . 30 Blasting , 36 Timbering 39 Haulage 45 Moisting 51 Preparation of coal 53 ILLUSTRATIONS Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. Fig. 7. Fig. 8. Fig. 9. Fig. 10. Fig. i l. Fig. 12. Fig. J 3. Fig. 14. Fig. 15. Fig. 16. Fig. 17. Fig. 18. Fig. 19. Fig. 20. Fig. 21. Fig. 22. Fig. 23. PAGE Map showing area (shaded) of District IV Frontispiece Copy of Joliet's map made in 1674 9 Copy of Marquette's map published by Thevenot, 1681 10 Typical clay vein i 16 Displacement due to horizontal movement 17 Typical block room-and-pillar mine 22 Wing-room turned to avoid roll i 23 Rock dump at longwall mine 25 Photograph of underground refuge chamber 27 Sketch of underground refuge chamber 29 Stopping built of Pyrobar block.. .. 31 Pyrobar block showing core holes 32 Fire-seal repaired with Pyrobar...: 34 Concrete overcast , 35 Typical method of placing shots after undercutting 38 Entry sixteen feet wide without timber 39 Three-piece entry set .< 40 Crossbar set in hitches in ribs 41 Steel I-beams and concrete at bottom ■. 42 First gasoline mine-locomotive in Illinois 45 Parting at mouth of room-entry 48 Tipple designed for local trade and shipping 54 Typical surface plant of shipping mine 56 TABLES NO. PAGE 1. General data by counties for the year ended June 30, 1912 12 2. Comparative statistics for District IV and the State for the year ended June 30,. 1912 14 3. Analysis of No. S coal in District IV 15 4. Dimensions of workings in feet 20 5. Per capita production of coal 26 6. Tonnage per fatal and non-fatal accident 27 7. Causes of accident to employees 22 8. Pressures developed by dust of face samples in explosibility apparatus 30 9. Data relative to ventilation 33 10. Blasting data '. 37 11. Data concerning props in rooms 44 12. Comparison for each district of number of props used in rooms 44 13. Ton mileage of locomotives 46 14. Amount of air required for ventilation with various sizes of gasoline locomotives 47 15. Data relative to underground haulage 50 16. Hoisting data 52 17. Preparation of coal for market 55 18. Surface plant equipment..... 57 )l-(.l.» Fig. 1. Map showing area (shaded; ol JJistrict iV. BULLETIN OF ILLINOIS COAL MINING INVESTIGATIONS COOPERATIVE AGREEMENT Issued bi-monthly VOL. I No. 7 COAL MINING PRACTICE IN DISTRICT IV By S. O. ANDROS Field work by S. O. Andros, C M. Young, and J. J. Rutledge INTRODUCTION District IV of the Illinois Coal Mining Investigations as shown in fig. 1, includes all mines in seam 5 of the Illinois Geo- logical Survey correlation operating in ('ass, DeWitt, Fulton, Knox, Logan, Macon, Mason, McLean, Menard, Peoria, Sanga- mon, Schuyler, Tazewell, and Woodford Counties. A detailed description of the districts into which the State has been divided and the method of collecting the data upon which this report is based are contained in Bulletin 1, "A Pre- liminary Report on Organization and Method of Investiga- tions." Comparative statistics have been compiled for the year ended June 30, 1912, although later information is available, because statistics for the seven districts previously reported on have been compiled for that year. The discovery of coal in District I Y was made early. Up to the present time the first mention of coal in the country which afterwards became the United States has been errone- ously credited to Father Louis Hennepin, who shows on a ma]) published in 1689 the location of a "cole mine" along the Illinois River. The credit for this first mention of coal does not, how- ever, belong: to Hennepin for the first discover? of coal in the 8 COAL MINING INVESTIGATIONS United States by Europeans was made by Joliet and Mar- quette in 1673. Margry's account 1 of Joliet's voyage says, "The said M. Joliet adds, That lie had set down in his Journal an exact Description of the Iron-Mines they discovered, as also of the Quarries of Marble, and Cole-Pits, and Places where they find Salt-Petre, with several other things." Joliet's map of 1674 2 (See fig. 2) shows the location of "Charbon de terre" (coal) near the present city of Utica. La Salle in his letter to Frontenac (1680) referring to the Illinois River 3 says, "We have seen no mines there though several Pieces of Copper are found in the Sand when the River is low. There is the best Hemp in that Country I have seen anywhere, though it groAvs naturally without culture. The Savages tell us, that they have found near this Village some yellow Metal ; but that cannot be Gold, according to their own Relation, for the Oar of Gold cannot be too fine and bright as they told us. There are Coal- Pits on that River.'' Marquette's Journal was first published in France by Thevenot in 1681. 4 Accompanying the narrative was a map (See fig. 3) copied by Thevenot from one made by Marquette. Both original and copy show the same location of "Charbon de terre" as does Joliet's map. Father Louis Hennepin, a Recollect priest, accompanied La Salle's expedition to the Illinois country in 1680 as chap- lain and in his "A New Discovery of a Large Country in Amer- ica," published in English in 1689, says with reference to the country along the Illinois River from its source to the site of the present city of Peoria : 5 "There are Mines of Coal, Slate, and Iron; and several pieces of fine red copper, which I have found now and then upon the Surface of the Earth, makes me believe that there are Mines of it ; and doubtless of other Met- als and Minerals, which may be discovered one time or another. They have Already found Allom in the country of the Iro- quoise." Hennepin's map accompanying this narrative 5 locates ^ecouvertes et fitablissements des Francais, I, p. 261. Published at Paris, 1681. 2 Thwaites, Jesuit Relations, Vol. 19, p. 86. 3 Margry, Vol. I, p. 465. 4 Recueil de Voyages. 5 Thwaites, Hennepin's New Discovery, Vol. I, p. 152. INTRODUCTION THE CENTRAL PORTION OF JOLIET's MAP, 1674, SHOWING THE MISSISSIPPI AS THE "BAUDE." Fig. 2. Copy of Joliet's map made in 1674 (From "A History of the Mississippi Valley, by Spears and Clark ) 10 COAL MINING INVESTIGATIONS INTRODUCTION 11 a "cole mine" on the Illinois River above Fort Crevecoeur (Peoria) copied from Joliet's map or Marquette's. Other early mention of coal in District IV is made by Patrick Kennedy in his journal of an expedition undertaken in the year 1773 from Kaskaskias Village in the Illinois coun- try in search of a copper mine. Under the date of August 6, 1773, he writes 1 , "At sun-set we passed a river called Michili- mackinac (Mackinaw River in Tazewell County). Finding some pieces of coal, I was induced to walk up the river a few miles, though not far enough to reach a coal mine. In many places I also found clinkers, which inclined me to think that a coal mine, not far distant, was on fire, and I have since heard there was." In 1823 2 Peoria was called "a small settlement in Pike county on the west bank of the Illinois river, about 200 miles above its junction witli the Mississippi." Beck says, "This section of country is not very rich in minerals. Coal, however, is abundant on the banks of Kickapoo creek, about one mile above* its mouth. It was first discovered by the sol- diers stationed at the fort (Clark), and being of a good quality, Avas used by them for fuel. It is found 12 or 14 feet below the surface; is overlaid by slate, limestone and sandstone; and contains vegetable remains." By 1S37 the existence of workable coal was known in three newly created comities in the district. In McLean County it was stated 1 "Of the minerals, limestone and coal abound in several settlements/' A description of Peoria County published in the Peoria Register and North-western Gazette 4 contains the following statement: "The stone-coal is said to be little inferior to that of Pittsburg, and is found in the bluffs of all the creeks and Illinois River. It is generally used for fuel at Peoria in winter; is hauled from one to three miles, and is worth 12 cents per bushel." In Schuyler County 3 , U^icks, Thomas Hutchins. A Topographical Description, p. \2~. -Beck. Gazetteer of Illinois and Missouri. ■Illinois in 1837 & 8: With A Map. 4 April 8, 1837. 12 COAL MINING INVESTIGATIONS • — 3 £ ■^ o a o I puBH 3 PK 9 iq*o ao;oj\[ p2O0 Supsqq in pasri japAvod jo s§3>i -o^ OO^OOvoOOOtOsOO^O OOVOOi-iOlOOOli-icoOOOjf? o 8 O O co O O Tt- o o o P OOOOOnOJOO -i O 0) co tJ- to 00 OlOOtNtoOi-ivO M 00 O ~ On S33X0ldui3 9DBJJUS '0\[ S33AO|dlU3 •on ih;ox uoi;cj3do 3AIPE jo sX^p 3SBJ9Ay auiipEiu Aq pauiiu suoj^ suo; poqs in uoipnpojj JEOOq Suxddujs O0 0icoco0\00covoto O h oo ro 0) -I- In 00 CO m co OOO'-'l^wOOVOOllN.OOl h In N W O W to h-i w Q\ In VO to 0} co VO 01 co O O 00 m 1^)00 O VO O Tl" On Ov to O -T lo 00 co 01 OO VO m M N _ M M M ^ M M M M M CO to o to o o o o O hh O O N In vo" O 00 00" o o to vo to o\ O to to m vo ^t to oi i_r m on m" 00 01 01 w CO ^t 01 CO CO 00 "st- o ovoovooo ocoo OOOvO^-^)"001^TfcoOioO»0 £2 bo y o J c 2 "C «J^^^ k=s ^ c P 1) D c3 *>> £ be 3 l» rt u rt H.S 1- n a 2 c3< INTRODUCTION 13 "Mount Sterling was a thriving village of about 50 houses. Coal of a good quality was found within one mile of the town/' By 1870 the output of the district amounted to about 250,000 tons and in 1880 it had increased to over one million. In the year ended June 30, 1912, the production of the district was 8,523,903 tons, 14.8 per cent of the production of the State. This output came from 240 mines, 75 shipping and 165 local, employing 12,835 men and operating on an average 157 days during the twelve months. Only 7.5 per cent of the production is mined by machines and the district is characterized by wasteful and dangerous shooting off the solid with excessive charges of black powder. The average number of tons gained per 25-pound keg of powder is 20.8. Although the production of coal is only 14.8 per cent of the production of the State, there is used in District IV 31.2 per cent of all the black powder used in Illinois. The proportion of accidents caused by pit cars is remark- ably high, 33.3 per cent of the fatal and 45.7 per cent of the non-fatal accidents occurring from this cause. The accident record of the district is the best of any important district in the State. Table 1 gives general data for the district and Table 2 comparative statistics for District IV and for the State. Thanks are due to the operators of the district who will- ingly allowed examination of their mines and to the superin- tendents and mine managers who accompanied the engineers through the mines. Especially generous assistance was rendered by Mr. F. S. Peabody, President, Peabody Coal Company; Mr. F. J. Devlin, Superintendent, The Jones and Adams Coal Company; Mr. Horace Clark, President, Clark Coal and Coke Company; Mr. M. S. Coleman, Superintendent, Big ('reek Coal Company; and the officials of the Woodside Coal Company. Professor C. W. Alvord of the University of Illinois gave valuable aid in deter- mining the site of the first discovery of coal. 14 COAL MINING INVESTIGATIONS Table 2. — Comparative statistics for District IV and the State for the year ended June 30, 1912° 1) Proximate analvsis of coal : < 6 Ih (h £n O 2 >£ ^ s 4 ft., 8 in. 54 i5-io 36.79 37.59 10.52 3.52 10514 Dry 43-33 44.28 ' 12.40 4-15 12384 14447 Udden states that, "in the mines near Easl Peoria and at Edwards the coal runs out against the drift in several of the entries. Miners recognize that these defects in the coal are due to erosion and they speak of the drifl as 'wash.' The drift generally consists of sand or silt, which in some places has been found to contain embedded trunks of trees and other vegetation. Experience has shown that the surface of the bed- rock does not always conform to the present topography of Illinois Geological Survey, Bull. 14. Coal Resources of Illinois, DeWolf. 16 COAL MINING INVESTIGATIONS the land and operators are careful to avoid unprofitable explo- rations of places where 'wash' has been encountered." 1 The immediate roof is a black sheety shale locally called slate. This shale varies in thickness from a few inches to 35 feet and in places contains "niggerheads" of iron pyrites. In many mines between the coal and the shale there is in places ■ -^ '^*m \ * . W'Jts* ?:..'; i*"" tt V " ' K -i • > ■ K "^^jHH *" .ftMQfarf'tj ?£*" Fig. 4. Typical clay vein a layer of iron pyrites two or three inches thick. Where this layer is present the shale is protected from the air and stays up; where it is not present the shale falls badly and in places caves to a height of 35 feet. 1 U. S. G. S. Bull. 506, Geology and Mineral Resources of the Peoria Quad- rangle, Illinois, Udden. DESCRIPTION OF COAL 17 The cap rock in most mines is limestone but in a few is a fine-grained micaceous sandstone. In some places the shale of the immediate roof is absent and the cap rock conies in contact with the coal. "When the limestone is disseminated and min- gled witli the shale the roof is soft and Aveathers quickly owing perhaps to the presence of marcasite. 1 It is then called clod and the niggerheads are iron carbonate. Fig. 5. Displacement due to horizontal movement (Photo by .1. A. Udden) Prom the viewpoint of the miner the chief characteristic of the district is the great number of clay veins extending through the coal and roof shale crossing their bedding planes. Pig. 4 shows a typical clay vein. These clay veins are tissnres which have been tilled with a hard light-gray clay. Besides clay veins the physical features which affect mining are small 'Udden, op. cit. 18 COAL MINING INVESTIGATIONS faults, slips, and rolls. In one mine where the shale of the immediate roof is absent the sandstone has cut out the coal for 150 feet along an entry. Fig. 5 shows the result of horizontal movement near Peoria. "A wedge of sandstone has divided the roof shale part of which continues under the sandstone and part above. 1 In the figure "a" is dark shale with some streaks of coal somewhat shattered; "b" is the roof shale; "c" is the coal seam; and "d" is sandstone. The coal in this district in many places sticks to the roof and is separated from it with difficulty. In one mine about an inch of coal is left up to protect the roof shale from the moist- ure of the air. The floor in most places is a dark-gray fireclay which heaves badly when wet. At one mine the floor is a blue fireclay containing nodular concretions of iron pyrites. 1 Udden, op. cit. MIXING PRACTICE 19 MINING PRACTICE Seam 5 in this district dips at the rate of about five feet to the mile towards the southeast. It outcrops in Peoria, Ful- ton, and Knox Counties and in the face of the bluffs of the Illinois River. The cover is thickest in Macon County where the coal lies at a depth of 600 feet. There is one stripping on a surface outcrop and there are 96 mines at which the coal is reached by drifts. At the remaining 143 mines shafts or slopes are sunk to the seam. The mines examined vary in depth from 60 to 570 feet but all except two were less than 300 feet deep. In the closed workings 235 mines are worked on the room- and-pillar system. Four mines are operated on the longwall system. Mining methods in most of the room-and-pillar mines are crude and dimensions of workings are not suited to physical conditions. The mines are comparable to those in the Dan- ville District 1 where the many rolls in the roof cause devia- tions from projected systems. The workings are irregular and in some small mines are but little better than "gophering." The district is characterized by many horsebacks where the roof, either sandstone or limestone, cuts out the coal. The original method of mining in the district is to run the parallel main entries from the shaft toward the boundaries, and from the main-entries <<> turn cross-entries at intervals of 350 to 400 feet. Rooms are turned off these cross-entries on 30 to 42-foot centers and are run 20 to 30 feet wide. Room-pillars are gouged as the miner pleases and average 9 feet in width. This hap- hazard method is productive of so many squeezes that in some mines a modification of the system has been made in which stub or room entries are turned off the cross-entries. This method approaches the panel system and is called locally "block iAndros, S. O., Coal Mining Practice in District VIII (Danville), Illinois Coal Mining Investigations, Bulletin 2, 1914. 20 COAL MINING INVESTIGATIONS H B p3UIH.§ Lillys JO ;il30 J3J ~t O ^ -t N "5 1\ *t (^1 VO 00 lo lo lo lo lo O u) O -t lo -t O 0) io o o o LO O O LO LO ON <;s3Z33nbs puq 3UIUI s^n DOOqjO^OOajaJaj ^ ^h >^ £ : aj;li3 uiooj UO SlUOOJ '0^[ "5 : O 00 : : m : -t -t ) ooooo -t O 'o o o : c) CM O) M o) l PP!A\ -to o -r -r *i o o x o lo 01 01 CO 01 01 01 oj ro 01 01 0) O O -t t lo On co co 01 o o lo ; : -t co -t co : : uibjvt OOOOO lOOOXOO IO ifl iO T "t "1 05 IO CO O ""O o lo o lo o : O ^ 'O '■O X ! Si lUOO^J -t : ^1 X : : -t O : O O i O O O O : : co o| r.) Cxi ; ; SSOJ3 O^LoO^t^lOO-fvo-t CO 0J l-i 01 O) h- CO C>) CO CO O) O -I" O t O : co 0) rv- f\) co ; UIHJ^[ OOOloOloOOOloO COCOON 01 co-h co 01 cococo lo i^ O O O : co 01 co co C) ; lUOO^J X : ^i X ; : X X : X o, \, _ ^, Q^ !M 05 HH 1-1 hi hi (M Hi 1-1 l^ lo 00 O i-i o O, rv, CO hh Suiuiui JO UI3}SA"g l-l J-i *1 )- a 'a 'a 'a 0>'O'a3'aj'T3'O ^ o* a i a a -T s .jT.jt s g .j, .r g ,r.r 5g££SoSgo£P aj a>a;00gjOqja; -Oh^cOcOD^^COcOC^COCO Semi-panel Semi-panel Semi-panel Semi-panel Room-and-pillar Longwall ;jbijs jo ipdaQ 1> D «J voao o loaaioo i^x » Ol^iOX o oxox^o M co MMM coco^^ M ^ LO io -t O io o CO "*t O 1^ O K 01 01 01 01 CO lo 'Oil 3UJH 1 LO O W X ON -1 01 co -t lo O i^ X On O i-i N 01 01 01 01 01 cococococococococo' , T MINING PRACTICE 21 room-and-pillar." (See fig. 6. ) In a few mines a sufficient cross- barrier pillar is left to confine a squeeze to the block in which it originates but in most mines the barrier pillar is gouged and squeezes ride over it extending unchecked until they reach a horseback or some ungouged pillar which is large enough to stop them. In several mines squeezes originating in rooms have traveled to the main barrier pillar and to the solid coal at the entry face. In one mine an entry Avas saved from a threatened squeeze by very heavy timbering ahead of the squeeze. Eleven of the 16 mines examined are at present operated on this semi-panel system but the relative dimensions of room and room-pillar have not been changed from previous opera- tion. The average room is 26 feet wide 1 and the average room- pillar 9 feet. These dimensions are unsafe under the roof found in the district. Room width is not uniform but rooms are narrowed to avoid horsebacks and widened again where the coal resumes its normal thickness. There is a temptation to get all the coal possible on the advance working because the numerous rolls make uncertain the total tonnage which can be extracted from any area, and the rolls interfere seriously with any projected plan because they are expensive to cut through. When a roll is encountered in turning a room off an entry work on this room is stopped and a "wing-room" is turned off the adjacent room. (See tig. 7). The wing-room carries tin 1 side 1 of the roll as a rib and follows its course until the room reaches the position it would have occupied if it had cut through the roll. It is then continued on ils proper course. Cleat is not sufficiently developed to be a factor in the direction of driving rooms. Cross-cuts are sometimes driven at irregular distances to avoid cutting through the rolls. Room-necks vary in width from S to 12 feet and are gen- erally widened on both sides to reach fall room width but the angle of widening varies. The distance from the entry to the point where full room-width is reached varies from 15 to 35 feet. Room track is almost alwavs in the center of the rooms 22 COAL MINING INVESTIGATIONS Fig. 6. Typical block room-and-pillar mine MINING PRACTICE 23 and the gob is thrown on each side of the track. Table 4 gives dimensions of workings at the mines examined. Pillars are drawn in only a few mines and in those drawing is not done systematically but is confined to shooting slabs off the pillars where they are thickest. In nearly all mines room- ii i iiii iri i ii ii iiiiii ii iiii i i ii iii vr Mil i u m Fig. 7. Wing-room turned pillars are tapered to cross-cuts as shown in fig. 7. In one mine an attempt was made to draw pillars and track was laid along the rib but objections were raised by the miners to this position of the track and the attempt was abandoned. The floor is a fireclay which heaves badly even when dry. 24 COAL MIXING INVESTIGATIONS The principal cause of the heaving flour is insufficient pillar- width. One of the mines examined is now worked on the longwall system although it was opened on the room-and-pillar system. This mine is worked by the 45-degree advancing system and the method of working does not differ from that employed in District I. 1 Room centers at the longwall face are 42 feet apart and the face between centers is called a "place." Two men work in each place. The clay under the coal is undercut with a pick to a deptli of two feet and is Avedged down as needed to fill cars. The miners at each place are required to brush two feet of roof along the roadway and to build packAvalls to protect the roadway. Where the amount of rock obtained from the miners' brushing is not sufficient for com- Xdeting the packwall, "company men" make a further brush- ing on the permanent haulage ways and bring to the face the rock thus obtained. Two men can average 10 % tons of coal daily. The coal at this mine averages 4% feet in thickness and the amount of rock hoisted is less than in mines in Dis- trict I. When producing 750 tons of coal per day there are only 18 to 20 tons of rock which can not be used underground in the gob. In District I about one-third as much rock as coal is hoisted. There is considerable difficulty in cleaning up after a suspension of working. After a shut-down of three months it takes two weeks to clean the mine during which period about 125 tons of rock per day are hoisted. Fig. S shows the rock dump at this mine. Although the mines are shallow operators have very little trouble with seepage water and at no mine is more than 30,000 gallons of water pumped in 24 hours. Several mines are muddy but the water drains off easily into the sumps at the shafts or is pumped to them by electric gathering pumps from small sumps inby. The shallowest mines are the muddiest and the water seeps through the roof or comes in where breaks to the surface occur. One or two gasoline pumps are used at the main sumps but in general the main pump is operated by steam and the gathering pumps by electricity. The source of the iAndros, S. O., Coal Mining Practice in District I (Longwall). Bulletin 5, Illinois Coal Mining Investigations, 1914. MINING PRACTICE 25 water can be told by its character. Where the water is acid it has been derived principally from seepage and its acidity is caused by the solution of iron sulphate; where it is neutral chemically it is surface water which has seeped through the shaft directly into the sump. At one mine it is sufficiently pure to be given to the mules which are stabled underground. Fig. 8. Rock dump at longwall mi The labor in the district is of various nationalities. Ameri- cans perhaps predominate but there are many Italians, Ger- mans, Hungarians, Poles, Lithuanians, and Croat ians. Tabic 5 gives the per capita production of coal for the mines exam- ined, the district, and the State. The small percentage of its production which is undercut accounts for its low per capita tonnage as compared with the remainder of Illinois. Face workers average only 5.8 tons per day in District [V as com- pared with 7.4 tons for all other districts combined. The per 26 COAL MINING INVESTIGATIONS 33AOTdlU9 oi in. CO O o O In. X X (O CM O co LO 01 NO jad Xep jad suoj^ 4 CO- CO |aOM-9DHJ \6 4 IO -r o 'f CO d tN. LO In. In [aOM.-90T3j; G MD o W pimcuS-iapuQ LO o CM ir, o o LO o X o In O CM LO "I LO NO O z CM o -1 o In O 01 LO O o CM In CO NO of 01 0} CO CO •*t -1- CO CO 01 " o o ON O aoHjing LO oi O O i^ o -1- LO CM In LO LO ^ M CO o LO O On CM CO 01 CM CO CM LO > ^ u. *d 'Oil 3UIJ\[ io no In. X On ,_, CM CO t LO o ^ X On o M 01 w f underground refuge chamber Where there have been so many squeezes under compara- tively shallow cover surface subsidence is to be expected. Sur- face cracks and subsidence seem to be related to the absence 30 COAL MINING INVESTIGATIONS of limestone cap rock. Where sandstone is the cap rock sub- sidence is more marked. Several cases of damage to buildings and of broken foundations have been reported and in some instances after a squeeze sink-holes, 9 to 10 feet deep, have appeared in fields. The percentage of extraction of coal from the seam in room-and-pillar mines in the district is low varying from 50 to 65 and averaging 54. VENTILATION The coal of this district generates very little explosive gas and therefore it is not necessary to supply extraordinary quan- ties of air to the working face for the purpose of gas dilution. In only a few of the mines examined is gas found in sufficient quantity to make a cap in a testing lamp. Gas is found in some mines in roof caves and it occurs casually in small quan- tities in abandoned areas. An occasional accident occurs from ignition of small bodies of gas in these areas. The quantity of air supplied to the working face is generally adequate for proper ventilation. Table 8. — Pressures developed by dust of face samples in explosibility apparatus Pressure in pounds District No. samples per square inch at 2192 degrees F. I ii 8.400 II 5 5.88o Ill 5 7.805 IV 7.700 V 7 7-105 VI 16 5-950 VII 24 7-175 VIII 6 8.925 The coal dust on the ribs and roof of rooms near the face is explosible as shown in Table 8. Coal dust on the ribs of entries is intimately mixed with finely ground shale and fire- clay and is kept moist in many mines by seepage of surface MINING PRACTICE 31 water. At some mines the rib dust along all entries is wet. The admixture of shale dust and water with the coal dust accounts for the comparative freedom from explosions which the district has enjoyed. The moisture extracted from the dust by the air current is continuously replaced by seepage. The humidity of the mine air is normal. Hygrometers were in- stalled by the Illinois Coal Mining Investigations in the intake and •eturn of the three following mines: Empire No. 2 mine, Fig. 11. Stopping built of Pyrohar block Clark Coal and Coke Company, Peoria; Peerless mine, Jones and Adams Coal Company, Springfield ; YVoodside mine, Wood- side Coal Company, Springfield. Headings three times daily were made at each mine during the working year. The average temperature of the outside air during the months these mines operated was 40 degrees F. The average temperature of the return air was 63 degrees F. The relative humidity of the out- side air was 70 per cent and of the return air in the mines 94 per cent. Details of this study of humidity of air in Illinois mines can be found in Bulletin 83, U. S. Bureau of Mines, The Humidity of Mine Air, by R. Y. Williams. The average size of air shafts at the mines examined is 7 by 10 feet. The average width of fan is 4 feet and the average 32 COAL MINING INVESTIGATIONS diameter 13 feet. At one mine in which insufficient air was being given by the fan a booster fan was installed underground near the end of the main entry. The present intake of this mine is 26,200 cubic feet per minute. It is reported by the oper- ators that before the installation of the booster fan the intake was 10,800 cubic feet. At most mines the fans are always run as blowers but in a few they exhaust in summer and blow in winter. At tAvo Fig. 12. Pyrobar block showing core holes mines the intake air is heated; at one by passing it over a eoil of one-inch pipe 695 feet long through which live steam is passed at a pressure of 80 pounds per square inch ; at the other by jets of steam exhausted into the air shaft from the fan engine. At these mines it is stated that in the coldest Aveather the intake air at the bottom of the air-shaft lias a temperature above freezing. Clean-up expense in this district can be les- sened materially by heating the intake air and every mine in the district could profitably install a steam eoil or drum. The initial expense Avould be small and the expense of operation slight compared a\ itli the saving in clean-up cost. The shale roof spalls off badly in spring and summer in many mines and in some continues to fall till the limestone or sandstone cap MINING PRACTICE 33 rock is exposed. In several mines in new entries driven dur- ing- winter the roof begins to fall with the advent of summer and caves to the cap rock. The cause of the falling is chiefly the expansion of the black shale with the rise in temperature of the intake air current. Maintaining the air current at a more nearly constant temperature by means of preheating with steam coils would decrease the roof falls by decreasing the seasonal range of temperature. Table 9. — Data relative to ventilation Air shaft Fan 8 6 c .~ 3 c u x: . s- Type u 5"~ 1" 25 26 27 28 29 3i 32 33 34 35 36 37 38 39 40 4i 42 185 196 I/O 150 185 60 68 285 203 l62 200 235 245 204 270 365 5/0 8 by 8 8 by 15 6 by 14 5 by 10 8 by 16 9 by 15 6 by 9 6 by 12 5 by 10 6 by 8 7V2 by 15 10 by J 4 6 by 12 io by 12 2 2 1 2 2 1 2 2 2 3 2 2 Paddle-wheel Sturtevant Paddle-wheel Paddle-wheel Paddle-wheel Duncan Paddle-wheel Robinson Paddle-wheel Paddle-wheel Stevens Buffalo I ; orge Jeffrey C appell Jeffrev 15 63/4 12 2;) 16 10 \2 1-' I-' 12 If) IO 6 10 15 3/2 4 4 7 4 6 4 6 4 6 4 5 4 7V2 3V2 \ X A by 7 6 by 8 \ 2 Stevens Duncan 2 a Paddle-wheel refers to straight blad< type of tan often home made. (Job stoppings are built in most mines and in many they are leaky allowing a large percentage of the air blown by the fan through the intake to short-circuit into the return before reaching the faces of the rooms. At one mine a tight gob stop- ping is provided and w considerable amount of gob removed from the road by tilling the entire cross-cut through the 20- foot pillar. At two of the mines examined tight stoppings are 34 COAL MINING INVESTIGATIONS built of Pyrobar blocks as shown in fig. 9. Pyrobar is a gyp- sum block made in two sizes: 12 by 30 by 4 inches and 12 by 30 by 5 inches. For decreasing weight three longitudinal core holes are made in the blocks as shown in fig. 12. The block 4 inches thick has a compressive strength of 154 pounds per square inch and the block 5 inches thick a strength of 162 pounds. The greater compressive strength of the block five inches thick is due to greater thickness of its walls. The four- Fig. 13. Fire-seal repaired by Pyrobar inch block weighs 12 pounds per square foot of surface and the five-inch block, 13% pounds. The price of the four-inch block is four cents per square foot, f. o. b. Fort Dodge, Iowa. The Pyrobar block is well adapted to mine stoppings and fire seals in dry mines where it is not subjected to heavy roof set- tlement. The blocks can be sawed into desired sizes with a hand saw. The mortar used in building stoppings with this material has a gypsum base and costs $6.50 per ton. Two men can build three 6 by 12-foot stoppings in eight hours. In this district a 6 by 12-foot stopping in place costs f 6.50 ; about nine cents per square foot of surface. Fire seals can be built MINING PRACTICE 35 easily and quickly Avitli these blocks which are fire resistant. Fig. 13 shows a broken fire seal repaired with Pyrobar. Many mines in the district are troubled with small fires which originate from two causes: the use of excessive charges of black powder at the face in blasting coal and the mixture of fine coal and iron pyrites in gob in damp rooms and entries. Almost all of the fires are quenched with water before they attain serious proportions but some of them require sealing off. Fig. 14. Concrete overcast The usual seal is built of concrete and costs from 50 to 100 dollars in place. In some mines an unnecessarily expensive mixture of concrete is used. In a few mines seals are built of brick and gob. Table gives ventilating equipment. The shafts of the mines examined were all sunk before the passage of the law requiring fire-proofed linings and each one of the air-shafts is timber-lined. For carrying the intake air over the return airway over- casts are built at all but one mine at which an undercast has been excavated and the intake air carried under the return airway. Overcasts are constructed of timber only, timber and 36 COAL MINING INVESTIGATIONS concrete, old rails or steel I-beams and concrete, concrete only, brick and timber, brick and steel, and Pyrobar. Fig. 14 shows a concrete overcast at a point Avhere the haulage way underlies a railroad track on the surface. To prevent possible subsid- ence of the surface and consequent damage to the railroad track the approaches to the overcast are made 5 feet thick and the floor of the overcast is reinforced with 4-inch steel I-beams. At those mines at which there were water gages, previous to the passage of the State law requiring water gages at all mines, the readings varied from 1 to 3% inches. At one mine the fan is driven by an electric motor; at all of the others examined the fan is steam driven. BLASTING In District IV only 7.5 per cent of the annual production is mined by machines. The remaining 92.5 per cent, 7,885,063 tons, is gained by shooting off the solid. In no other important district in Illinois mining on the room-and-pillar system is so small a percentage of the production undercut. Dangerous and wasteful excess of black powder is used in blasting coal. At one mine where two men were killed by a blown-out shot a drill hole Avas measured eleven feet in length and three inches in diameter. At many mines the number of tons of coal gained per keg of powder has decreased from 25 to 19 since the intro- duction of shot-firers. The miners drill longer holes and put in heavier charges Avhen they do not fire their oAvn shots and consequently are not exposed to the danger resulting from bloAvn-out shots. The excess of poAvder above that necessary to bring doAvn the coal shatters the coal producing an unneces- sary amount of slack, cracks the roof increasing the danger of accident from roof- fall, and causes fires at the face. Black poAvder is used in every room-and-pillar mine in the district. At one mine size CC only is used; at six, C only; at two, C and CC ; at four, F only; at two, FF only; and at one F, C, and CC. In the longwall mines 40 per cent dynamite is used in roof brushing. In a feAV places Avhere the coal in longwall mines is tight size CC black poAvder is used for blast- MIXING PRACTICE 37 q S3ipuI t>^I J3AO IBOO JO JU3D J3J S3lpUI 111 S9J0l[ JO J3J3UIKIQ }93J HI S3[OL[ JO q}§U3^ [BOD JO HO} J3Cl SJU33 III }SOD J3pA\OJ J3pA\OCl jo S^y\ jdcI jbod jo siioj^ [eoo jo no; J3d JOp.Wod jo spunoj JD|)A\OCl JO 9Z| S Oil DUIJ,\[ o O o o O ir. 05 a 8 o 1^ o in s C 8 8 hs en O CO CM in 01 Ol fl Ol N 01 fl P) 05 oq « cm hh oi CO ir, a ro o\ o ^oq 0) co oc -1- tN l^ CJ C3 ON X 1^ Q\ >0 00 X O 0\ iO c c r ""- co -r ro 'O vo M d - M c d 00 M C « O fe Uh C U ^UU^^^^^U^U^UUUUfeUU be be be be be be be be be be be be be be .£ .5 .5 .£ .5 .5 , c .5 .5 .E .5 .S .5 .5 oo oc o o o ooooooo CO O O OC O ooooooo — en c/3 en en Tr. -i ^i HH Hi ^^ -UOD3g x *0 'O *c C i- 3 O c c ■* H a : O O c +-> >> £ £ & ^ To X ^ 9§emeu o o VO O O VO u-) to VO VO O >r, in VC O VO CO Tf HH CO CO Xf ^- co hh co CO CO CO 01 HH rt UIBJ/\[ rt S3LJ3UI VO (M VO VO VO VO VO 01 VO VO VO 01 o 01 to Tf 00 UI 9§E§ >J3BJX CO -T CO CO co r o co -^r CO co CO n- ^t CO 01 CO ' VO o C cu cu CJ u o o ^H (J u u uiej^ CU CU 5 ^ S S w o 01 CO ^ - to vO r^ oo o C HH (N i 'ii °". l J\L 01 01 01 01 01 r o c 5 co c 5 c 5 CO CO CO CO ^ r tj h ^ - 9^ MINING PRACTICE 51 Ties are usually of white-oak aud on the main haulage where locomotives are used have the dimensions 6 by 8 inches by 5 feet and on the secondary haulage 1 by 6 inches by 5 feet. At a few mines old props are used as ties. The construction of underground stables complies with the State law. The stable at one mine is lined with brick and old boiler plates are used for ceiling. The provision of the State Mining LaAV to the effect that no light with an unpro- tected flame shall be taken into an underground stable is fre- quently Adolated but no oftener than in other districts. This provision should be strictly enforced throughout the State. HOISTIXU In District IV at 106 mines cars are hoisted from the bottom by steam; by horses at 43; and by hand at 90. The moderate daily production of the mines of this district and the comparatively short hoists require neither elaborate ap- pliances nor great speed of hoisting. Tin 1 hoisting equip- ment is adequate for their needs. The average daily produc- tion of the mines examined is about 1200 tons and the longesl hoist 570 feet. As the mines with hoists longer than 300 feet have a production of less than 800 tons daily all of the coal mined can be raised to the surface by slow hoisting. Because speed of hoisting is not essential there is no automatic caging at the mines examined. The size of the average hoisting shaft is 71/2 by I51/2 feet. At slope mines hoisting is often done by a partly balanced rope on a two-track incline where 1 the weight of the descending empties assists in hoisting the loads. At slope mines second-motion engines are used but at all except one of the shafts a first-motion engine hoists the cage. The cylinder size varies from 12 by 15 inches to 24 by 36, aver- aging 18 by 32. The self-dumping cage is used at 11 of the mines examined but at most of the mines in the district the operators have purchased the platform cage. Weighing is done at the tipple throughout the district. Table 10 gives hoisting data. 52 COAL MINING INVESTIGATIONS Table 16. — Hoisting data. 60 Hoisting shaft Engine Drum 6 c T3 ■ £J bo g ^ > a < 'a, g bo CO .5 Q ll CO 6 S c -M ° C/J * J Cylinder size in inches U -> a .a 25 1200 Yes 185 8 by 16 Yes 18 by 36 5 6 26 900 550 Drift 27 Yes 170 6y 2 by 18 Yes 18 by 36 6 7 28 950 Yes 150 8 by 16 No 14 by 20 6 8 29 1 100 Yes 185 8^ by 15^ Yes 18 by 36 6 6 31 32 1200 Slope Slope 90 68 7 by 8 No 550 6 by 12 No 12 by 15 33 1600 Yes 285 8v£ by 16 Yes 24 by 40 8 354 34 650 Yes 200 7 by 14 Yes 16 by 32 6 7 3 /4 35 2/5 No 187 8 by 16 No 12 by 15 5/ 2 4^ 36 2450 Yes 238 0V3 by 19 Yes 24 by 36 8 6 37 2700 Yes 235 10 by 16 Yes 24 by 36 7 5 38 1400 Yes 245 7 by 14 Yes 20 by 36 6 2 39 2400 Yes 204 10 by 20 Yes 22 by 36 7 3 40 700 Yes 270 8 by 16 Yes 18 by 2>6 6 2 41 325 No 365 6 by 16 Yes 16 by 24 6 8 42 750 No 570 8 by 16 Yes 20 by 36 8 7 PREPARATION OF COAL 53 PREPARATION OF COAL This district was among the first in Illinois to attempt to remove the separable impurities from coal and to separate sizes. Several large cities are located in the district and the local trade for domestic purposes has always been and still is a prominent factor. Fig. 22 shows a tipple designed for hand- ling the local trade and shipping. Those mines located in or near cities naturally separate the coal into more sizes than the others and for this purpose several of them have installed re- screening plants. A typical separation at a mine catering to domestic or "wagon" trade is: Name Size in inches 6-inch lump Over 6 3-inch lump Over 3 l^-inch railroad lump Over 1% 6-inch egg ( her 3; through 6 Nut Over 2 ; through 3 Pea ( )ver % ; through 1% Screenings Through % At those mines which do not have a local trade the sizes commonly made are: Name Size in inches Lump Over 6 Egg Over 3; through 6 Nut Over 1%; through 3 Screenings (Steam) Through V/± Many mines ship run-of-mine coal and the percentage of the total production thus shipped varies from l 1 /* to 30. The location of some mines near cities having diversified manufactures and various kinds of domestic furnaces leads to particular demands. At one mine 30 per cent of the output is 54 COAL MINING INVESTIGATIONS crushed to 2-inch size for use in distilleries. At another, 8- inch lump and egg are in demand. Several mines make a nut through l!/4 inches and over 1 inch and one makes a "domestic lump'' over 3 inches. In the total output of this district about 80 per cent of the coal is larger than %-inch, 75 per cent larger than 1 inch, 70 per cent larger than 1% inches, 48 per cent larger than 3 inches, and 25 per cent larger than 6 inches. SP^rg Fig. 22. Tipple designed for local trade and shipping The impurities, shale, fireclay, and nodules of pyrites, are separated as far as possible at the face. Where fireclay is shot up with the coal the separation underground is comparatively easy on account of the contrast in color. A further picking is made at many mines on the screen and car; six pickers being employed at some mines. Screens are of various types. They are built with one, two, and three decks and have a throw of 8 to 12 inches, mak- ing 75 to 80 shakes per minute. At one mine the screen is split into two compartments longitudinally, each division being five feet Avide. Table 17 gives data on coal preparation. Power is usually obtained by burning slack under steam boilers. The largest installation at any mine examined is 750 H. P., the moderate outputs requiring only moderate horse- power. The efficiency of these power plants is low. From 3.2 to 4.3 per cent of the output is burned under boilers at the PREPARATION OF COAL 55 surface plant. Good combustion under boilers is obtained at one mine by the use of steam blowers and the slack burns with no clinkers. Wasted coal ranges from 0.5 to 0.7 per cent, There is no power plant at one mine. Electric power is purchased at 2% cents per kilowatt-hour. Three-phase GO cycle alternating current is brought to the plant at 4000 volts and there transformed to 275 volts. The installation consists of three 15 H. P. motors. Alternating current is reported to be less satisfactory for haulage than direct, but by using an A. C. locomotive a converter is dispensed with. Table 17. — Preparation of coal for market M-, Shaker screen ^ Per cent of 6 O r^ CO ^ cy total output ■5 w 53 1 - 31 W 1 31 7 80 Neither 67 20 32 Wood 30 6 1 80 Neither OS 20 33 Wood 68 8 3 7«S Rescreened 75 50 34 35 Wood 30 6 4 3 79 80 67 25 Wood 36 Neither 36 Wood i_> 80 Neither 67 33 37 Wood ?'? [2 3 80 Neither 65 30 38 Wood 38 6 4 76 Neither 39 Steel 15 15 3 80 X either 70 32 40 Wood 46 4 3 80 Neither 71 33 4i Wood 6 75 Rescreened 7<> 42 Wood 7 Rescreened :l : '6,S per cent over 2 by 21-inch hoi Steel tipples have been Imill ai four of the mines exam- ined. Pig. 2:\ shows a typical surface plan! in the district. Automatic recording I rack scales have been placed al several plants and at one pi! cars are weighed <>n automatic scales which weigh each car and prinl the weight automatically. 56 COAL MINING INVESTIGATIONS PREPARATION OF COAL 57 In a few instances where platform cages are used cars are pushed by hand on to a revolving cradle and dumped. Box car loaders are found at several mines. The surface overlying the workings is owned by the oper- ators at some mines and at one it is farmed, and corn is raised for 36 mules. Table 18 gives surface plant equipment. Table 18. — Surface plant equipment 6 No. loading tracks beneath tipple No. cars stored above tipple Boilers Electric generators c s 5 f^ • B CO £ M > 25 2 40 5 /CO 90 200 250 26 3 30 150 250 27 4 40 3 700 70 ICO 250 28 4 40 3 225 [00 150 250 2Q 4 23 2 250 100 100 250 3i 4 45 6 875 90 300 250 32 4 25 3 250 90 100 250 33 2 5o 6 750 105 150 250 34 3 35 2 250 95 50 [25 35 3 20 3 i/5 80 100 225 36 3 55 5 700 90 37 4 120 5 750 90 200 250 38 3 5o 4 600 100 150 250 39 4 100 4 600 "5 45 125 40 4 25 3 185 80 100 250 41 2 20 4 280 80 5o L5° 42 2 iX 4 35<> 1 10 8 no PUBLICATIONS OF THE ILLINOIS COAL MINING INVESTIGATIONS Bulletin 1. Bulletin 2. Bulletin 3. Bulletin 4. Bulletin 5. Bulletin 6. Bulletin 7. Bulletin 8. Bulletin 9. Bulletin 10. Bulletin 11. Bulletin 12. ♦Bulletin 72. ♦Bulletin 83. Preliminary Report on Organization and Method of Investigations, 1913. (Out of print.) Coal Mining Practice in District VIII (Dan- ville), by S. O. Andros, 1914. A Chemical Study of Illinois Coals, by Prof. S. W. Parr. (In press.) Coal Mining Practice in District VII (Mines in bed 6 in Bond, Clinton, Christian, Macoupin, Madison, Marion, Montgomery, Moultrie, Per- ry, Randolph, St. Clair, Sangamon, Shelby, and Washington counties), by S. O. Andros, 1914. Coal Mining Practice in District I (Longwall), by S. O. Andros, 1914. (Out of print.) Coal Mining Practice in District V (Mines in bed 5 in Saline and Gallatin counties), by S. O. Andros, 1914. Coal Mining Practice in District II (Mines in bed 2 in Jackson County), by S. O. Andros, 1914. Coal Mining Practice in District VI (Mines in bed 6 in Franklin, Jackson, Perry, and Wil- liamson counties), by S. O. Andros, 1914. Coal Mining Practice in District III (Mines in beds 1 and 2 in Brown, Calhoun, Cass, Fulton, Greene, Hancock, Henry, Jersey, Knox, Mc- Donough, Mercer, Morgan, Rock Island, Schuy- ler, Scott, and Warren counties), by S. O. An- dros, 1915. Coal Resources of District I (Longwall), by G. H. Cady, 1915. Coal Resources of District VII (Counties listed in Bulletin 4), by Fred H. Kay, 1915. Coal Mining Practice in District IV (Mines in bed 5 in Cass, DeWitt, Fulton, Knox, Logan, Macon, Mason, McLean, Menard, Peoria, Sang- amon, Schuyler, Tazewell, and Woodford coun- ties), by S. O. Andros, 1915. U. S. Bureau of Mines, Occurrence of Explosive Gases in Coal Mines, by N. H. Darton, 1915. U. S. Bureau of Mines, The Humidity of Mine Air, with Especial Reference to Coal Mines in Illinois, by R. Y. Williams, 1914. *Copies of this bulletin may be obtained by addressing the Director, U. S. Bureau of Mines, Washington, D. C.