July 7, 1916. THE COLLIERY GUARDIAN ... ________________________________________________________________________________ 29 HORSE v. COMPRESSED AIR HAULAGE.* By Raoul Green. The following comparisons only apply to mines work- ing under the following conditions :—Seams pitching 25 degs. or more; pit cars containing two or three tons; rails weighing 30 to 401b. per yd.; grades fluctuating but little from 0-46 to 1-00 per cent, in favour of the loads; gangways roomy; tracks fairly well kept; curves few and slight. Compressed Air Haulage. An average summer month of 1915 was chosen for the test. The output was 33,826 tons, and the number of haulage shifts 19-5. All expense chargeable to haulage, including work done on idle days, holidays, and Sundays, has been allocated to that item. Two hundred 3-ton steel cars were in use, equipped with 18 in. Hadfield wheels. The gangway was laid with 401b. rails. Besides the morning haulage shift, an afternoon and a midnight shift were employed. Only sufficient drivers were occupied on the midnight shift to fill all cars in preparation for the day shift, beside handling such supplies and material as are always needed in a coal mine. These extra hands being chargeable to haulage, tend to increase costs, especially if there are many idle days. All locomotives were of the H. K. Porter stan- dard compound type. The haulage comprised two operations : Firstly, the gathering or loading from the mine chutes, and haulage to a main parting—the trips consisting of some 10 to 20 cars, with 6-ton locomo- tives; secondly, the haulage of 40-car trips, from the main parting to the tipple approach, by the use of 9-ton locomotives. The monthly expenses amounted to :—Track cleaners, drivers, trackmen, etc., 2,335 dols.; power house labour, 599 dols.; material repairs, cars, boilers, locomotives, 426dols.; coal and other supplies, 1,238 dols.—total, 4,598 dols. In order to obtain an accurate account of depreciation costs, the following items were taken from the equip- ment ledger:—Char, haul., 13,345 dols. (being 50 per cent. prop, of 26,690 dols. cost of boilers, pumps, heaters, and headers); two horse-power com- pressors, 25,000 dols.; eight locomotives, 28,300 dols.; pipe lines, 12,800 dols.; 200 cars, 30,000 dols.; boiler and power house at 50 per cent. prop, charg. haul., 5,000 dols.—total, 114,445 dols. Depreciation at 11 per cent, for one month would equal 1,048 dols. Ton miles handled for the month, 70,260. Cost per ton mile per item :—Mine labour, 0’033 dol.; power house labour, 0-007 dol.; material repairs labour, 0-006 dol.; coal and other supplies, 0-017 dol.; equip- ment 11 per cent., 0-015 dol.—total, 0-078 dol. If a full month’s run had been realised, that is, if the shipments had reached, say, 41,000 tons instead of 33,000, the theoretical cost would have been 0-060 dol. instead of 0-078 dol. However, it is doubtful if this figure would be reached in practice, as it is based on all the costs decreasing in the same ratio as the tonnage increases, which, in this case, is obviously untrue. For example, the mine labour, the material repairs, and the supplies increase practically in the same ratio as the tonnage. Again, the power house and equipment accounts are more or less fixed in their total, whatever the tonnage. Probably 0-070 dol. would be a very con- servative figure to take in such an instance. Horse Haulage. The details of conditions under which the test was carried out were :—Total tons shipped during the month, 15,573; days haulage worked, 25. The cars were steel framed, wooden boxes, of 2-ton capacity, 18 in. Hadfield wheels; rails, 401b. to the yard; tracks in fair condi- tion—no sharp curves; grade quite uniform, averaging 0-5 of 1 per cent, in favour of the loads. An afternoon shift of drivers was employed in order to prepare a full string of loaded cars for the morning shift. Good heavy horses were used. The haulage consisted of two opera- tions :—First, hauling from the mine chutes by single horses to a main parting; second, hauling from the main parting to the tipple approach by means of a three horse spike team, 20 to 25 pit cars composing a trip. The monthly expenses amounted to : Track cleaners, drivers, helpers, 884 dols.; repairs to cars, etc., 164 dols. Supplies and attendance on 22 horses totalled 330 dols. Depreciation charges : For horses this figures as follow, averaging over a period of five years : Total horses owned, 83, value 16,600 dols. Less horses killed, 20, value 4,000 dols.; loss on 28 horses sold, 3,560 dols.; loss on value of balance, 3,500 dols.—total, 11,060 dols. Loss in five years, 66 per cent., or 13 per cent, per year. Depreciation on horses : 22 horses at 200 dols. each equals 4,400 dols. at 13 per cent, yearly, for one month equals 48 dols. Depreciation on equipment :—130 pit cars at 110 dols. each = 14,300 dols.; stables, stable equipment, tools, 2,966 dols.—total, 17,266 dols. Depre- ciation at 11 per cent, per year = monthly 167 dols. The total monthly expenses are therefore as follow : Labour, 1,048 dols.; supplies, 330 dols.; depreciation horses, 48 dols.; depreciation equipment, 167 dols.— total, 1,593 dols. Total ton miles hauled, 14,450. Comparison per Ton Mile. Compressed air. Horses. Dol. Dol. Labour ............... 0-046 .... 0-072 Supplies .............. 0-017 .... 0-022 Depreciation .......... 0-015 .... 0-015 Total cost ........ 0-078 .... 0-109 The conclusions to be deduced from the above facts are that :—First, compressed air haulage is about 3c. * From a paper read before the Rocky Mountains branch of the Canadian Mining Institute, per ton cheaper than horse haulage; second, cost of supplies and depreciation are about the same in each case; third, compressed air permits of from two to three times as much coal (in certain cases probably more) being handled than by horse haulage; fourth, the main reason for lower cost by compressed air is due to the labour item, in this case about 3c. per ton; fifth, the total of 7-8c. per ton for compressed air haulage could undoubtedly be reduced to 7c. for a month of 25 work- ing days. _____________________________ THE LANCASTER PISTON THROTTLE VALVE. A new valve, for winding, hauling, and reversing mill engines has been introduced by Messrs. Lancaster and Tonge Limited, of Pendleton, to obviate jerking when starting the engine. It has been designed to replace the ordinary type of double-beat valve, and to keep con- tinuously steamtight, whilst balanced sufficiently for all practical purposes. As shown in the illustration, there is only one seat, and the piston is provided with ordinary rectangular rings to prevent escape of steam. Owing to the arrangement of the seating, the valve opens very S3 n o is gradually, and is not subject to the same risk of leakage as double-beat valves, where the difference in expansion between valve and seatings makes the prevention of leakage difficult when once started. When fitted to colliery engines the valve allows a minimum opening for steam in the operation of.decking the cages, and it is also fitted with a spring (as shown) or weight, which ensures effectual closing in the event of the overwinding motion coming into action. ____________________________ THE COAL MINING INDUSTRY OF POLAND. The coal of the Dombrowa Basin is fairly uniform, and belongs to the “ lean ” class, burning with