One of the most difficult problems that the mining engineer has to deal with is the transmission of power to long distances. It is not proposed, however, to discuss here the various methods in which this may be effected but to describe, shortly, a successful attempt lately made at Broomhill Colliery to convey power by means of steam to a pumping engine, situated in-bye 1,294 yards from the boiler at bank, a distance, so far as the authors know, greater than has before been attempted, at least in this district. (See Fig. 1, Plate XXIII.)

In the first place, the writers were guided in their choice of steam by the special circumstances of the case, namely, that there was surplus boiler power already to hand, and that the steam had been carried 342 yards of the distance previously. The crookedness of the rolleyway also made transmission by ropes, which is being adopted for pumping upon a large scale in other parts of the mine, inadmissible.

There are upon the surface two cylindrical boilers, one 20 feet 6 inches long by 5 feet diameter, the other 29 feet by 5 feet diameter. They are used alternately, one boiler only being on at a time ; but the little boiler is found to be rather small for the work required. The consumption is 38 tons of small coal per pay.

The steam is taken, at 35 to 38 lbs. pressure, through 5-inch cast iron pipes, to the shaft 19 yards, and down the shaft 27 fathoms. Here is placed one of Tangye’s 5-inch steam traps and separators (Fig. 2), which, when the engines arc running, delivers about 9 gallons of water per hour.

The construction and action of this separator may be thus described : a, the top portion, is placed in the range of steam pipes by the flanges 1 and m; i i are two splash plates, which deflect the water carried along with the steam on to the perforated plate b, through which it drops into the lower portion of the separator c; d is a small floating cistern guided in its up and down motion by the projections g, and having a small valve f fixed to its bottom, which opens and closes the pipe e, through which the condensed water passes away at h ; k is a self-acting valve for allowing the air to escape. When the steam is first admitted, k falls by its own weight, and is shut by the steam as soon as pressure is obtained. When it is first set to work water is put into the bottom part to float the cistern d, which shuts the valve f; when sufficient water has dropped through the sieve b to cause the cistern d to fall, the valve f opens, and the condensed water is forced out through e ; the cistern then rises and again closes the valve f.

The greater part of this water will, perhaps, br due to priming or syphoning of the water out of the boiler, a phenomenon which, in spite of the baffle plates with which the boilers are fitted. appears always to accompany the use of steam a long distance below the level of the generator, more especially when commencing work and when the boiler is driven hard. These pipes are covered with Wormald’s composition, and the portion in the shaft is coated in addition with felt and lead. There are two expansion joints; one placed horizontally between the boilers and the shaft, the other vertically at the top of the shaft.

The 5-inch steam pipes are then taken a further distance of 269 yards, with a vertical fall of 44 feet, to a receiver 6 feet long by 3 feet diameter. The pipes and receiver are covered with Wormald’s composition, and there is one expansion joint inserted in this range. Near this receiver is placed a combined hauling and pumping engine, erected two years ago. It is a single cylinder horizontal engine, 2 inches diameter by 2 feet stroke, and makes 30 revolutions per minute, with a steam pressure of 32 lbs. (i.e., 6 lbs. less than the pressure in the boiler at bank, which is 342 yards off). It runs during the day for 11 hours out of the 24, and is laid off when the pit is idle. It hauls 120 tons of coal per day, up a bank 101 yards long, rising 3.12 inches per yard and 70 tons of coal per day up another bank, situated about half a mile further in-bye, 399 yards long, rising 3.35 inches per yard. It also deals with a constant feeder of 13 gallons per minute, which it forces 219 yards and 34 feet vertically, through 4-inch pipes, by means of a double-acting pump, 6 inches diameter by 1 foot 6 inches stroke.

The receiver is fitted with one of Tangye’s 4-inch stream traps and separators, from which about 17 gallons of condensed water are delivered per hour.

From the receiver, a range of 2½-inch wrought iron pipes is carried a further distance of 952 yards, with a vertical fall of 101 feet, to the in-bye pumping engine. Upon this range there are two of Tangye’s 4-inch steam traps, without separators (one 211 yards from the receiver, delivering about 10 gallons of condensed water per honr, the other placed near the in-bye engine, delivering about 31 gallons per hour ; this gives a total of about 67 gallons per hour for the total range of 1,294 yards ; in addition, there will be some condensation in the cylinders) ; and three expansion joints only, the crookedness of the road making more than this unnecessary. The steam pipes, traps, and engine are covered with Wormald’s composition.

The engine is a single cylinder horizontal engine, 8 inches diameter by 1 foot stroke, geared 3 to 2 to a Warner’s three-throw single-acting ram horse pump ; each ram is 4 inches diameter by 1 foot stroke.

The pressure of the steam is 25 lbs. (i.e., 13 lbs. below that in the boiler at bank, distant 1,294 yards as measured along the steam pipes, 314.42 feet vertical distance). Vacuum — obtained by turning the exhaust into the suction pipe — varies with the vertical distance of the standage, viz. :— 18.4 feet gives 13 to 14 inches vacuum ; 10.30 feet gives 7 inches. The vertical distances are measured from the level of the water to the vacuum gauge

The engine works for 6½ hours out of the 24, and 12 days per pay, at 55 revolutions per minute ; and deals with a constant feeder of 13 gallons per minute, which is drawn 37 yards up 14 feet vertically, and then forced 380 yards up 114 feet vertically. Forster’s 4-inch pipes are used, both for the suction and rising main.

It was first started in October, 1885, before the 2½-inch steam pipes were covered, and before the 5-inch steam pipes were covered in the shaft — i.e, with 1,240 yards of naked pipe out of the total of 1,294 yards. In these circumstances, the loss of pressure was from 27 to 30 lbs., as compared with 12 to 13 lbs. the present loss; but no measurement was made of the quantity of condensed water.

The installation was completed early in December, 1885, since which date it has been working regularly and satisfactorily.

Tangye’s combined steam trap and separator, Forster’s patent socket pipe, the expansion joint used upon the range of steam pipes, and the arrangement of pipes for turning the exhaust steam into the suction pipe, are given in Plate XXIII., Figs. 2, 3, 4, and 5. A plan of the drift, showing the pipes, levels, and position of engines, is given on the same Plate.

Since writing the above, the water has increased, and the feeder is now 16 gallons per minute. In addition, an accumulation of water in some old workings has been pumped out. The face of the workings is advancing, and preparations are being made to take the steam in a further distance of 100 yards