The Mechanical Handling and Storing of Material

COAL TIPS OR HOISTS 547 individual case, as a great deal must depend upon position and local conditions. This applies not only to the various systems, but also to the various types of hydraulic machinery. Sometimes direct acting cylinders below the cradle are the most suitable, whilst in other cases hydraulic cylinders at the side of the structure manipulate the cradle by means of cables or chains as the case may be. The first coal tips of this de- scription erected by Sir W. G. Armstrong, Whitworth, & Co., Ltd., consisted of a set of four at Cardiff, and another set of four at Newport. These were erected in the year 1858, and were followed in 1859 by the two tips at Swansea, and in 1861 by two at Briton Ferry. The latter were very similar to the Car- diff tips, which are of the type gener- ally built by the Armstrong firm. Since those days, however, the power and height of the lift has been very considerably increased with the increased size of ships, and so-called anti-breakage cranes have been added. The Cardiff Tip.—The general type of the first Armstrong hydraulic tip and hoist is shown in elevation in Figs. 770 and 771, whilst Fig. 772 gives a plan of the same. Tips of identical construction are now being built with a lift of 40 ft. and over above the quay. The cradle a which carries the wagon is raised by vertical hydraulic ram b, whilst the cradle itself is guided at its four corners by the framework, and the loaded wagon is raised to the level of the shoot e. The upper portion C of the cradle Figs. 770 and 77.1. Elevation of Cardiff Tip. forms the tipping frame, and is pivoted at the front and tipped with the wagon upon it by means of a second hydraulic cylinder d below the cradle, and attached to it as shown in Figs. 770 and 771. The cylinder oscillates on trunnions to follow the motion of the tipping frame, the hydraulic main being connected to the cylinder through one of the trunnions. The whole apparatus can be controlled by a man standing on a side platform f, at the top of the structure, with the levers controlling the machinery close at hand. The raising and lowering of the shoot E for adjusting both height and inclination are automatically effected and are quite independent of- hand labour. Two short arms