1898 - Coalmininghistorypa.org

No. 11. BUREAU OF MINES. xviithe long ton and at 403 by tlie short ton of 2,000 pounds. At 242mines the coal is screened and at oil run of mine is shipped. Miningmachines are used in every inspection district. The numberreported as in use is D02; of these, G20 are driven by compressedair and 273 by electricit}'. Air is used in DO mines and electricityin 357. There are reported to be 1,937 men operating mining machines,9,120 men loading machine mined coal, 54 men running electricmotors, and 73 electriciansf. There are 96 electric dynamos orgenerators, which are capable of transmitting 8,433 horse power.Three are alternating current and the others direct. Seventy-onehave a voltage of 250 and under; the other 25 have from 250 to 500.There are 54 electric locomotives equal to 2,714 horse power, and 4compressed air locomotives equal to 280 horse power. The numberof stationery engines in use outside is 813 and their combined horsepower is 70,835. There are 55 stationary engines ins'ide the mineswith a horse power of 4,038. There are 74 steam locomotives outsideand their combined horse power is 4,021. There are 17 steamlocomotives used inside the mines and their combined horse poweris 418. There are 553 steam pumps with a combined capacity of157,871 gallons per minute, 36 electric pumjjs with a combined cajtacityof 12,696 gallons per minute, and 223 other pumps with a combinedcapacity of 37,822 gallons per minute.The foregoing statistical matter is given just as received from theseveral Mine Inspectors, and it is presumed to be correct.The Jeffrey Manufacturing Company, which is extensively engagedin the manufacture of mining machinery, shipped its first miningmachine into this State in 1878. These machines were of the "aircutter bar" type, which was the earliest type of machine used forundercutting coal. From that time until 1889 the air cutter bar machinewas the only one used in the State of Pennsylvania, undercuttinga uniform cut in height and width.While of late the increase in the use of mining machines in thebituminous mines has been very general, it has not been greater thanthat in mechanical haulage, by electricity^, compressed air or wirerope, all of which have their supporters, and each of which commendsitself to certain conditions. While rope haulage has beenin use for many years, improvements are still being made which addto its efficiency. The application of electricity and compressed airto mine haulage is of recent date. The first electric locomotiveshipped into this State by the Jeffrey Manufacturing Company wasfurnished and shipped in the latter part of 1894. Since that timethey have probably shi])ped about 50. H. K. Porter and Company,of Pittsburgh, have built and furnished for use in the bituminousmines two compressed air locomotives, 8x14 cylinders, classes B-P. P.;one locomotive, 7x14 cylinders, class B-P. P.; two 9|xl4 cylinders,B.—11—98