898 THE COLLIERY GUARDIAN. May 11, 1917. MINE UNWATERING WITH AIR LIFT * , By S. H. Brockunler. The unwatering of the Herman Mine at Westville, California, recently accomplished, presented some unusual features. The large pump had been sub- merged through the carelessness of a foreman, and the small pumps, while efficient, were not capable of hand- ling the water rapidly. It was therefore decided to try air lifts. The shaft was inclined at an agle of 52 degs., and was 400 ft. deep. When the mine was closed down, three years before, 256 ft. of 4 in. air column was left in the shaft, with the expectation of using it for ail’ to run the pumps and drills at a higher level. The lower end was therefore closed, but water leaked in, and the column was found full. It was decided to use this air pipe for the lift, but before doing so it was necessary to shoot the lower end off, and this involved several nice problems. The length of the column was first carefully measured by weighting a steel tape and lowering it within the column. It was then calculated where a shot should be placed to come midway between the wall plates of the shaft, near the bottom of the pipe, so that it would not disturb the timbers. The cartridge was prepared by binding four sticks of 40 per cent, dynamite tightly together, priming it with two electric detonators, attaching their ter- minals to No. 18 insulated copper wire, carefully bind- ing the connections with waterproof tape, and daub- ing the latter with pitch. In order to use the insu- lated wire for lowering the cartridge, as well as for firing it, a half-hitch was made with the wires around the cartridge, securing them firmly, so that there would be no pull on the detonators. The cartridge was weighted by attaching to it a piece of 1 in. pipe cut to such a length that it would support the cartridge at the place, above the bottom of the column, where it was desired the explosion should occur. The preliminary tests were made with the insulated wire and detonators by firing a pair of detonators under water, after a submergence of half an hour, when it was found that it took six ordinary dry cells connected in series to get good results. When every- thing was ready, the cartridge was lowered nearly to the bottom of the column before meeting an obstruc- tion—a tee, as was afterwards found. If it had not been for the pipe weight, the work would have been held up at that point, but by gently raising and lower- ing the cartridge, the pipe finally guided it by the obstruction, and landed firmly on the bottom, as was shown by a mark previously measured off on the con- ducting wires. Several hundred feet more wire was then run off and connected to one terminal of the batteries; it was then a simple thing to fire the cart- ridge by touching the other terminal of the batteries to the remaining conducting wire. Subsequent unwatering showed that the column had been cut cleanly at the exact point desired. The factors for the air lift were now : 5,000 ft. eleva- tion, compressor capacity 1,250 cu. ft. free air per minute compressed to 1001b., 253 ft. of 4 in. pipe in shaft at slope of 52 degs., giving a vertical head of 199 ft. From these data it was decided that a 1J in. air pipe within the column would furnish sufficient air to lower the water to the second level, at 164 ft., starting with a submergence of 100 per cent., and stopping with a submergence of 33 per cent. As a matter of fact, the air lift began to baulk at 40 per cent, submergence, and failed to unwater as far as the station by 20 ft., thus necessitating the lowering of the air lift to reach it. A pump head was made by grinding down a 1| in. return elbow until it would slide inside the 4 in. pipe. To one side of this was screwed the 1| in. air pipe, and to the other side a 1J in. nipple 9 in. long. On the upper end of this nipple was screwed a cap perforated with in. holes, to act as the air vent for the lift. This pump head, with air pipe attached, was then lowered inside the 4 in. pipe to near its bottom, and the air turned on, with the usual result of inexperience— too much air used, resulting in shower baths for onlookers. However, the flow of air was soon regu- lated, and the water flow for several weeks, night and day, averaged 180 gals, per minute, as measured over a dam. Subsequently, two additional lifts were put in, consisting of 2 in. pipe with side inlets, of 1 in. pipe with J in. nozzles. These delivered 40 gals, per minute each. All failed below 40 per cent, submer- gence. ' The consumption of air and power to operate these lifts was much higher than the theoretical figures, but ’this is partly explained by a break that was found in the large water column after unwatering. After reaching a depth of 164 ft., the remainder of the unwatering had to be done by pumps. This was much slower, even with the smaller amount of water con- tained in the lower workings. It is uncertain whether the shot caused the break in the column, two lengths above the location of the shot, or whether it was there before. The air could be heard bubbling up, but the trouble could not be located: If anyone should repeat this experience and hear air bubbling or boiling in the mine, our advice is to first locate the break by raising and then lowering the air pipe within the column, and listening to the sound. If the break is too far up, it will be best ‘to abandon the fixed column if possible, and lower another. This would be rather a difficult job in an inclined shaft full of wreckage of stulls and timbers, but by careful manipulation and using a large wooden cone attached to the lower end of the column, it might be accomplished. It was expected to submit careful tests of power and air consumed, but the break of the main column ren- dered these useless for comparison with normal work- * Engineering and Mining Journal. ing conditions. But even with these unfavourable circumstances, six weeks’ time was saved, and the cost was 1,330 dols. less than it would have been had the pumps available been used—judging by their expense and rate of work when they were used after abandon- ing the air lifts. THE MECHANICAL COAL BARGE. In connection with the recent announcement that a cargo of coal had been conveyed by a motor-driven barge from Cannock Chase to London, Messrs. Coggins and Arthur, of Birmingham, who-—in collaboration with Mr. A. E. Hooke—are the inventors of the system of -wB Fig. 1.—Elevation of Stern End, showing Propeller in the Two Positions. Fig. 2.—Section of Propeller, Shaft and Rudder. mil! propulsion employed, have favoured us with the subjoined description of the motor attachment and log of the trip. The motor, shown in fig. 1, is of the four- cylinder Sterling marine type, developing 17 b.h.p. at 600 revolutions per minute, and is geared down 25 per cent. Being mounted on the top of the barge cabin, some modi- fication of the reversing gear was required, the re- versing lever being arranged horizon- tally instead of vertically. The motor cover also houses the fuel tanks. The motive power is trans- mitted to the pro- peller through two shafts, both of which are telescopic. The horizon! al shaft is fitted with uni- versal joints at each end, in order to allow the neces- sary play, both in the lateral direction, for steering, and vertically ; whilst the telescopic con- struction gives play for steering, allows the position of the engine to be ad- justed in relation to its distance from the stern post of the barge, and facilitates the detaching of the shaft. Table A.—Log of Coggins and Arthur’s Portable Marine Engine Tkip to London by Canal. Date. Place. Time. Miles travelled. Locks traversed. Time occupied. Detail. Total. Detail. Total. Detail. Total. 1917. April 23 Aston Wharf to Camp Hill ■ 3A Hrs. rm Hrs. m Left Camp Hill 2.30 p.m. — — — — — Arrive top Lock Knowle 6.10 a.m. 10 — — — 3 40 — ,, bottom Lock Knowle 6.50 „ 1 144 6 6 6 40 4 20 „ top Lock Hatton 10.15 „ 82 23 — — 3 25 7 45 „ bottom Hatleys Lock 12.40 p.m. 34 26| 23 29 2 25 10 10 „ „ Radfords Lock 2.10 „ 5A 31f —- — 1 30 11 40 ,, top Wigrams Lock 6.35 „ 74 39| 22 . 51 4 25 16 5 ,, Braunston bottom Lock 8.40 „ 6 45| — — 2 5 18 10 „ „ top Lock 9.25 „ 1 464 6 57 0 45 18 55 ,, Buckby top Lock 10.30 „ 24 484 — —- 1 5 20 0 ,, ,, bottom Lock 11.55 ,, 1 49$ 7 64 1 25 21 25 April 24 ,, Stoke Bruerne top Lock 5.40 a m. 15 64| — — 5 45 27 10 „ ,, „ bottom Lock... „ Cosgrove Lock : ’ 7.5 „ 1 654 7 71 1 25 28 35 9.0 „ 6 71f 1 72 1 55 30 20 v ,, Fenny Pound 1.0 p.m. 111 x 834 — — 4 0 34 30 ,, Slap ton 5.0 „ Ilf 95 8 80 4 0 38 30 „ Bulborne top Lock 9.0 „ . 54 1004 16 96 4 0 42 30 ,, Cawroast 10.0 „ 3 1034 — — 1 0 43 30 April 25 ,, Rickmansworth 6.45 a m. 16 1194 29 125 8 45 52 15 „ Cowley bottom Lock 12.10 p.m. 9| 129 15 140 5 25 57 40 ,, Paddington Stop 5.45 „ 18 147 — — 5 35 63 15 ,, destination 7.15 „ 44 1514 4 144 1 30 64 45 Totals ' — 1514 144 — 64 45 (J Average speed 2’28 miles per hour. Fuel consumption 2 miles per gallon (two boats, or 494 tons). Note.—For arriving at the fuel consumption, the total distance (viz., 1514 miles) has been used. The vertical shaft (fig. 2), Which also acts as rudder shaft, is housed in a tube secured to the stern post, and is also telescopic to allow the rudder and propeller to be adjusted vertically, according as the barge is running loaded or empty. In fig. 1, A B represents the water line in the former case, and C D the water line of the empty barge, and the vertical adjustment is effected by turning the threaded rod in the rear of the shaft housing. The rudder has two blades, one on each side of the propeller. The motor furnishes sufficient power to tow a butty barge, thus hauling a load of 100 tons ; and the engine and attachments can be transferred from one barge to another in a few minutes, so that when an empty barge is returned to the colliery, the motor, etc., can be shifted to a loaded one in waiting, and thus kept constantly in use. No difficulty is experienced in passing through locks (of which there are a number between Cannock Chase and London), as the etigine is under the complete control of the steersman. The motor is driven by paraffin, with a small proportion of spirit substitute, though petrol is required for starting. Table A below is the log of the first trip to London, towing a butty barge. With reference to this new system of traction, a mining corre- spondent writes that the trip proved so successful that the introducers now propose to equip the whole of their barge fleet with the loose motor. The railway charges for conveyance from the Cannock Chase coal field to London are 7s. 6d.. per ton, and it is declared that the new invention will show a considerable saving, the canal dues being under 3s. a ton. One of the advantages attendant on the new traffic system is declared to be that the Cannock Chase pits employing it will be able to work more regularly, instead of, as now, sometimes experienc- ing short time three or four days a week owing to the shortage of railway trucks. COKE OVEN PLANT OF THE FUTURE. The annual meeting of the Yorkshire section of the Society of Chemical Industry was held last week at the Queen’s Hotel, Leeds, Prof. J. W. Cobb presiding. The following officers for the ensuing year were' appointed:—Chairman, Prof. Cobb; vice-chairman, Mr. W. McD. Mackey; hon. secretary and treasurer, Mr. T. Fairley; committee, Messrs. J. E. Bedford, B. A. Burrell, S. H. Davies, C. P. Finn, W. M. Gardner, A. G. Green, C. H. Hardy, F. W. Richard- son, J. T. Thompson, Dr. Ingle (Leeds), Dr. Paul (Huddersfield), and Mr. Frank Wood (Barnsley). Mr. G. E. Foxwell, of Sheffield, read a paper on “ Some Future Lines of Advance in Coking Practice.” He pointed out the necessity for shortening the car- bonising period in order to increase the output, and argued that coke oven bricks as at present used in England were far from satisfactory. Apart from improvements in the coking process, great advances were capable of being made, he said, in connection with the recovery of by-products. For instance, a method was wanted which would enable the ammonia to be recovered as sulphate, using the sulphur con- tained in the coal to provide the necessary sulphuric acid. Naphthalene was another compound which had been neglected. The market for this product was growing. The present system of recovering 65 per cent, benzol was not the one calculated to give the best results. It was found in practice that by manufac- turing benzol of 55 per cent, strength there was a very considerable increase in the amount of toluene recovered. It seemed, therefore, preferable to recover benzol of much lower strength than at present, and to wash it for phenol. It would be very advantageous also if a system could be found whereby the carbon disulphide could be recovered from the gas before taking out the benzol. In all probability, the coke oven plant of the future would not stop at the recovery of crude 65 per cent, benzol, or washed 90 per.cent, benzol. It would manufacture pure benzene, toluene, and xylene, probably also nitro-benzene, nitro-toluene, aniline, toluidine, and possibly pure