EAST GRETA COLLIERY. 331 



tion, which causes the cage to be in a different position when 

 partly loaded to what it is when empty. To allow for this dif- 

 ference, a sheet of iron is used at the flat, so that a skip can be 

 pushed sideways before running it on to the cage. There is 110 

 necessity to have such sheets at the upper levels, as there is- 

 not so much spring in the shorter length of rope. The down- 

 hill side of the level near a flat is a little lower than the up- 

 hill side, so as to compensate for the inclination of the angle. 



The levels are so arranged that any water gravitates to- 

 wards the tunnels, from which it is at present bailed, but 

 will shortly be raised by pumps. When sinking for another 

 lift, the water is dammed back in a portion of the lowest level, 

 and the tunnel continued in its proper direction, but a twelve 

 foot pillar is left between the bottom of the former lift and the 

 commencement of the new, which is finally broken through 

 when the new lift is completed. An electric winch is employed 

 for hoisting while sinking the new lift. 



A new electric plant has been installed, which consists of 

 two thiee-throw Worthiiigton pumps of the horizontal pressure 

 pattern, with pot valves. These raise 145 gallons per minute in 

 two lifts, each of 700ft. The upper pump is 6in. by 12in., and 

 the lower Gin. by 9in. These pumps are driven by belt from 

 a dynamo. The motor has 710 r.p.m., which is reduced to 41 

 r.p.'m. at the pump. 



The main winding engine was made by B. and J. Morisoii 

 and Bearby, of Newcastle; it is a duplex 22in. cylinder, with a 

 4ft. 6in. stroke. There is one 7ft. drum divided in the middle 

 by a brake path. The enginedriver has two electric pushes 

 worked by his feet, so that he can signal to the men working 

 at the tunnel both on the surface and underground. 



A British-Westinghouse direct current generator com- 

 pound wound, of 12.5k.w., 250 volts, with 400 r.p.m., is used 

 for electric lighting and for driving an electric winch. 



The main tunnel is 10ft. Gin. high, 12ft. wide on top, and 

 13ft. wide at the sill inside timbers. It is supported by full 

 sets of round iroiibark timber, not less than 8iii. diameter , 

 placed 4ft. apart, and closely slabbed at the back and sides 

 with ironbark slabs 2in. thick. The legs are shouldered and 

 morticed into both cap anl sill, while the cap and sill have 

 15in. horns let into hitches in the sides, so as to keep them 

 from falling down hill. There are no distance pieces between 

 the sets. When additional sets are used for further support, 

 they do not have horns. At flats where levels branch off and 

 legs have to be omitted, the cap-pieces are picked up by strin- 

 gers, which rest on legs placed out of the way of the opening. 

 There are two tines of rails. These are not fastened to special 

 sleepers, as they would be shifted by the swelling 1 of the bottom, 



