The Mechanical Handling and Storing of Material

54° THE MECHANICAL HANDLING OE MATERIAL capstan, is '3 kilowatt. After the truck is discharged it is allowed to descend into the firstposition (see illustration), where it leaves the bogey on its own account, as the hooks holding it are auto- matically released as soon as the lowest position is reached. It is usual to have a branch siding for the empties so that the pro- gress of the full truck is not impeded and the tracks are laid with a slight downward incline. Figs. 754 and 755 show the same tip, but stationary instead of on wheels, at Bremen Harbour, where it has been installed by the North German Lloyd Co. Another construction is to have the curved bed for the tip formed of a block of concrete or masonry, as shown in Figs. 756 and 757, with a motor house and drivers’ stand at the top. This installation is at work at the Gasworks of Liege. The stationary appliances just alluded to are worked in identically the same manner as the portable ones, but they lend them- selves better for a somewhat greater lift and thereby save excavation for the further disposal of the material, as the trucks are lifted fre- quently by these appliances 5 to 10 ft. above the rail level. As regards cost of un- loading, from actual figures derived from the installa- tions, it may be seen that if 240 tons have to be handled