ZIG-ZAG COLLIERY. 115 



ment for pipes and ropes. The upcast shaft is 189ft. deep, and 

 is surmounted by a brick stack 25ft. high. The* brickwork 

 goes down to solid rock another 25ft. 



This shaft is 9ft. in diameter. The travelling road 

 is an incline (Fig. 54) steps being cut in the rock 

 to assist the men in descending. This travelling road, 

 which is a hundred yards long, relieves the shaft, so 

 that the engine has nothing to do but hoist coal and 

 lower material. The record output for the downcast shaft 

 from G a.m. to 5.30 p.m. is 678 tons. The hoisting engine is 

 an old-fashioned single cylinder one, with a flywheel, built b;y 

 John Cochrane, of Barrhead. The indicator is one of the 

 vertical type, and a finger on it strikes a bell when nearing 

 the end of a trip. The skips are kept on the cage by catches, 

 which prevent the axles of a skip from going past them. A 

 skip is run on the* cage over one of these catches, the tail of 

 which, being heavier than the head, causes the latter to rise 

 up after the axle has passed it. At one side* of the cage is a 

 pedal, and by putting his foot on this, the banksman depresses 

 the head of tha catch, so that the front axle o>f the skip can 

 pass over it: the front axle also depresses the head of the 

 catch by means of a lever, thus keeping it down for the back 

 axle to pass over. 



Ventilation is induced by a furnace. It has no side flues, 

 all the air passing over the fire. The furnace is 5ft. high, 8ft. 

 wide, and 12ft. long. Its arch is 14in. thick, built up of 

 headers set in loam, as this stands 1 the fire better than lime 

 inortar. 



Fig. 55. Diamond. 



Steam is conveyed down the main shaft to a receiver, 

 where any condensed water is separated, after which the steam 

 passes to a two-drum duplex engine of Tangye's make, geared 

 2 to 1. This drives the main and tail rope used for hauling 

 purposes, which travels at the rate of seven miles an hour. The 

 single line of rails has a gauge of 25in. Pulleys are bolted 

 on to timbers at the side of the roadway to support the tail 

 rope. The main tail rope is one mile twenty chains long, and 

 the cap of the rope is connected to the skip by a shackle. 

 There is only one branch line so far in connection with this 



