756 . HYDRAULICS AND ITS APPLICATIONS 



ART. 200. HYDRAULIC COAL TIPS. 



Fig. 373 shows one of a series of hydraulic coal tips designed to lift a 

 waggon of ten tons through a height of 45 feet and to discharge this 

 through the shoot S into the hold of a vessel. The lifting cradle C 

 is actuated by four rams, one small and one large one on each side. The 

 smaller rams are for the purpose of partially balancing the weight of 

 the cradle, and are in constant communication with the high-pressure 

 mains. These four rams are each 45 feet long, and press against 

 a cross girder above the cradle, which travels in vertical guides. The 

 cradle is suspended from tjiis cross girder by adjustable bolts, and the 

 tipping cradle rests upon the main cradle and is hinged on the end 

 nearest the dock. The shore end of the cradle for tipping purposes is 

 actuated by means of wire ropes which pass up from the shore end 

 of the cradle on either side to near the top of the tip framing, thence 

 over sheaves. The bight of the rope is carried over guide pulleys and 

 up to the side of the main cradle, where it is passed over a sheave 

 attached to the framing of this cradle. The tipping ropes from each side 

 of the cradle are by this means made out of one rope, and any inequality 

 in the stretch of either end of the rope is adjusted by the bight of 

 the rope traversing over this sheave upon the tip cradle ; this rope, which 

 acts the part of two ropes for the tipping cradle, is free to run round the 

 sheaves of the tipping ram and cylinder, as the main cradle lifts or 

 lowers, carrying the tipping cradle with it. 



The main cradles are fitted with cross girders above the ordinary 

 height of the top of a wagon, and should the tipping cradle be very 

 rapidly lifted, these girders act as a stop to prevent the wagon being 

 thrown off. There are two cranes on each tip, one capable of working 

 four tons and the other eight tons. All movements of the various 

 appliances are controlled from the elevated cabin on the side of the tip. 

 The point of the shoot can also be lifted or lowered from the same place. 



The butt of the shoot is lifted or lowered by means of the main 

 cradle, upon which there are a pair of sliding dogs, which may be pushed 

 out to engage in the shaft which carries the butt. The latter is 

 held, when the proper position is obtained, by means of chains, each 

 attached to one end of the shoot shaft and carried up to the top of 

 the tip framing, thence over sheaves and back down alongside the 

 middle frame of the tip, where there are suitable cleats arranged into 

 which these chains are placed, and there secured by bolts. The point of 

 the shoot is moved by means of wire ropes which pass up to the top 



