The Mechanical Handling and Storing of Material

526 THE MECHANICAL HANDLING OF MAI ERIAL Noeux station the boxes are raised by means of a hydraulic ram, whilst at the loading wharf they are manipulated by an ordinary crane. Coal Tip Built by Pohlig.—Another device which comes under this heading is that built by J. Pohlig, of Cologne, and illustrated in Fig. 733. The truck is held in position by a chain at the tail end, whilst the front buffers rest against a support specially constructed for this purpose, to take the weight without straining the buffer springs. Unlike the tips previously described, the one under consideration is manipulated by a band brake. The end of the cradle is weighted so as to bring it back to its original position when the truck is empty. The band brake is of such power that the truck can be held in any position. The tip is also fitted with a hand winding gear to be used if, in exceptional cases, the truck should not go back to its original position. Another and later type of tip by the same firm is shown in Figs. 734 and 735. The Stevenson Coal Tip.—This tip is illustrated in Figs. 736 and 737, and is also manipulated by gravity, and requires, therefore, no driving power. The mode of Fig. 733. Tip Built by Pohlig. working is to run the truck on to the tip, which is kept in a horizontal position by means of a powerful brake. Ihe position of the truck is such that its own weight will overbalance it as soon as the brake has been released. After the discharge of the truck it returns automatically into its original position. It is fitted with a shoot which can be housed out of the way when not in use, or the angle of which can be adjusted to suit the circumstances. Figs. 738 to 740 represent another type of Stevenson’s coal tip very similar to that just described. The illustrations show the appliance in plan and elevation, and the tip is shown, in Figs. 738 and 739, in its discharging as well as in its horizontal position. This particular tip is arranged so as to overhang the quay wall, in order to get the discharge of the tip right on the barge to be loaded. Figs. 741 to 743 show a further development of the Stevenson tip. The illustration consists of a longitudinal elevation and two cross sections, one through the tipping portion and the other through the framework extension. The appliance is arranged in such a way that it can be racked in and out. The whole apparatus is mounted on a