13 6 HYDRAULIC COAL-DISCHARGING MACHINES.

HYDEAULIC COAL-DISCHAEGING MACHINES.

In the year 1851 Sir William Armstrong devised the “Coal-Whipping Machine,” shown by Plate 34, for the purpose ofmore expeditiously discharging coal from Colliers on the river Thames , in lieu of hand-whipping. The load is raised by onestrolce of a steam-piston acting through multiplying sheaves onthe lifting-chain. At each side of the steam cylinder there is acataract plunger attached to the cross-head of the steam-piston,and the descent of the load is regulated by a valve, whichControls the passage of the water from the cataract cylindersto a small cistern above them. A vertical multitubular boilersupplies the necessary steam.

The upper side of the piston is in constant communicationwith the boiler, and when it is desired to make a lift, the lowerside of the piston is, by the movement of the starting-valve,opened to the exhaust. In lowering, the steam-piston is placedin equilibrium by admitting steam to the under side, and the.deseent of the load is controlled by the valve on the cataractcylinders. A tappet on the cross-head automatically shuts thestarting and cataract valves at each end of the stroke. A feed-pump for supplying the boiler with water is also attached tothe cross-head.

About the same time that the above machine was introducedon the river Thames , the Glamorganshire Canal Co. took stepsto improve the method of discharging coal, which resulted inthe fitting up by Sir William Armstrong of two hydraulicmachines at Cardiff . A wooden frame was placed at a suffi-cient distance from the quay to enable a truck of coals to standbetween it and the latter. The coals were discharged from thebarges or vessels on the canal by a bücket, which was raisedand lowered, swung inwards or outwards, by means of a vibrat-ing jib, all the operations being performed by hydraulic power.The action of these vibrating jibs (which were afterwards used