310 



COALFIELDS AND COLLIERIES OF AUSTRALIA. 



The pit top, including the pit head frame, tipplers, 

 screens and travelling belts are made of steel ; but the bank is 

 not attached to the pit head frame. (Fig. 198.) The skips 

 are brought up two at a time, tandem ways, in a single deck 

 cage, which runs on wooden guides at its ends, except near 

 the top and bottom of the pit, when they are changed to the 

 sides. On arrival at the bank, horns fixed to the top of the 

 cage pick up two bars looped loosely round two small vertical 

 ropes, one after the other. When a cage is below, these bars 

 protect the mouth of the shaft. The lower portion of the rope 

 on which the bars slide has gas piping round it. The loops 

 of the lower bar are large enough to pass over this and rest 

 on collars, but those of the upper being smaller, rest on the 



Fig. 199. Ormerod's Safety Hook. 



top of the piping, which thus serves to space the bars when at 

 rest. An Ormerod's safety hook is placed above the bridle 

 chains of the cage, and as an extra safeguard, in case of over- 

 winding, serrated bars are fastened at each end of the sides 

 of the cage, which engage with the projecting arms of an 

 overhead chair, thus holding the cage up. 



Ormerod's safety hook is shown in Fig. 199 A, B, C, and 

 D. (A) shows a cross view of the hook, and (B) a side view 

 of it, when in position for use, and under ordinary conditions 

 the plates are held in the position shown by the copper rivet 

 (p). In case of overwinding, the hook passes up through a 

 cast-iron thimble fixed at the top of the head frame below the 

 pit head pulley, and in doing so the wide portion at the bottom 



