The Mechanical Handling and Storing of Material

516 THE MECHANICAL HANDLING OF MATERIAL here described as being of historical interest. They have done good work in the past, but are now generally superseded by tips of later type. They are only applicable where the trucks are on the wharf at a high level, or where the railway lines are raised on staiths, from which elevation the coal is deposited by gravity down the shoot into the vessel. Hopper-bodied wagons, or wagons with hinged end doors, are employed to load into the shoot. In Newcastle the former wagon is more often used, and in Cardiff the latter. These balanced tips consist of a suspended cradle or platform a (Fig. 722), sliding Fig. 722. Balanced Gravity Tip of the Old Cardiff Type. in vertical guides, and supported by balance weights b connected to it on either side by chains passing over pulleys c at the top of the framing, upon which are brakes d for controlling the motion of the cradle. The balance weights are sufficient to raise the cradle and empty wagon, but are not equal to the load when a full wagon is upon the cradle. The contents of the wagons d are discharged through an end door into an inclined shoot e extending over the ship’s batchway, and sometimes having screens at the bottom for separating the dust from the coal. The brake is then released, and the cradle with the empty wagon rises to the top again, the wagon is run off into a siding, and the