SOUTH CLIFTON COLLIERY. 



163 



When necessary to blast down the coal, holes are bored with 

 augers, and charged with monobel ; for shooting in rock, 

 saxonite is used. 



Men enter the colliery from a tunnel driven in the side of the 

 cliffc' overlooking the ocean (Fig. 95) ; there are besides two 

 shafts which are circular and brick lined. The downcast shaft 

 is 150ft. deep, and is used for hoisting purposes ; the upcast air 

 shaft is 120ft. deep. The cages in the downcast shaft run on 

 iron rail guides ; these guides, two for each cage, are both 

 arranged near the outside of the shaft, so as to give more clear- 



Fig. 95. Entrance Tunnel. 



ance in the shaft. The winding is done by a duplex engine, 

 with 1ft. Gin. diameter cylinders, and 3ft. stroke. There are 

 double drums 7ft. Gin. in diameter, with a brake path between 

 them. The engines are direct-acting, and occupy 12 seconds to 

 hoist a cage from the bottom ; they are provided with link 

 motion reversing gear. Steam is shut off about half-way. The 

 rope is 4in. in circumference, and is 220ft. long from the pit's 

 bottom to the drum. A dial indicator shows the position of the 

 cages in the shaft. The pit head frame is built up of squared 

 timber, on which is mounted pit head pulleys 10ft. Gin. in 

 diameter. Steam is generated in two Lancashire boilers 30ft. 

 long, by 7ft. diameter, and one Cornish boiler, under a pressure 



