Volume Ten - Pre-Victorian to the present day - even more aspects - The Patent for the Penarth Slipway - 1881 . . .

With this system no disconnection or removal of links or bars is required. The only loss is the time occupied in the return stroke, which however is not great, as, owing to the small size of the ram, it is forced out much more rapidly than are the hauling-up rams, the respective areas being approximately as 1 to 19. During the short time the links are stationary, i.e., at the reversal top and bottom, water under pressure is accumulated, to be given out so soon as the rams are permitted to travel in one direction or the other.

It is obvious that several modifications of this hauling machinery can be made, all involving the upward and downward movement of the links as described, and in some cases the rams might be worked direct from a set of force pumps. The accumulator is, however, convenient not only as a means of economising time, but as a safety-valve to prevent shocks, and as a regulator for adjusting the speed of the engine or the working of the pumps, according to the demand for water.

1877 - Messrs. Hayward, Tyler and Co's. hydraulic hauling gear ; engravings of which were published within 'The Engineer'.

A few years ago Messrs. Hayward, Tyler and Co. constructed a hydraulic hauling gear with a double set of cylinders and rams. These were so arranged that while one set was in upward motion the other was returning. By attaching the hauling links first to one set of rams and then to the other the cradle was drawn up by an almost continuous motion. This arrangement would seem to be very costly in machinery and foundations, and would occupy considerable space, which the Authors venture to think would not be compensated by any advantage over their cheaper system.

More recently Messrs. Day and Summers have made hauling machinery in which an engine, working thorough gearing on to a large drum, rolled up a wire rope led from the cradle. This plan will no doubt answer well for moderate weights, but it is open to objection when applied to vessels of large dimensions, both on account of difficulty in making gearing to withstand enormous strains, and in obtaining wire rope sufficiently large, pliable, and durable.