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

◊ Slipways for Repairing Ships - Plate 5 - Figs. 1, 2, 5, 6 and 7.

The cradle, Plate 5, Figs. 1, 2, 5, 6, and 7, is a structure of timber, generally American oak, so constructed as to receive and maintain the vessel in very nearly the same trim as that in which it floats. It consists of a strong tapered centre rib, about 280 to 300 feet long, of several balks securely bolted and fastened together, forming the rest for the keel blocks, and two lighter ribs corresponding in position with the side ways. from the centre rib to each of the  sides stretch transverse pieces of iron or of wood, carrying sliding bilge-blocks, worked by ropes-and-gear from the deck of the vessel or from jetties. These jetties as a rule, extend either on one side or both sides of the ways (Plate 5, Figs. 1 and 2), for the purpose of affording convenience in placing the vessels on the cradle, and for superintending the whole operation, which it is important to complete without loss of time. The sliding bilge-blocks are trimmed with supplementary loose blocks, shaped to suit the size and description of the vessel to be hauled up. The cradle-ribs are carried on numerous cast-iron rollers, in cast-iron carriages (Plate 5, Figs. 5, 6 and 7), those at the centre being placed as close together as possible, while those for the sides, where the pressure is small, may be spread some distance apart. About ten of the centre-carriages are formed to receive the cradle-holding pawls, previously referred to. It is also usual to provide two or three short independent cradles or ekes, which may be attached to the top of the main cradle, according as the vessel to be repaired is long or short.

The other adjuncts of the cradle are - wrought-iron ploughs at the aft end of each rib for removing silt or mud, or any other obstruction that may accumulate on the lower portions of the rails ; hinged iron rods for guiding the keel of the vessel properly on to the centre of the cradle, one pair of rods being placed at the top of the bow, and a second pair at the bottom for the stern ; besides sundry gear for working the bilge-blocks, and for lifting and lowering the pawls.