The Penarth Floating Dock was constructed in 1909 at Wallsend to the order of the Penarth Ship Building and Ship Repairing Company, Ltd. The dock is of the off-shore or single-walled type, and is one of the finest of its kind. It has an over-all length of about 380 feet, an extreme width of 75 feet, and is capable of accommodating vessels having a beam of 55 feet, with a draught of water up to 18 feet, and a displacement of 4200 tons. Its pumping machinery consists of four centrifugal pumps and engines, for which steam is supplied by two large Babcock and Wilcox boilers, working at 160 lb. pressure. This plant can lift a vessel of 7000 tons dead weight in three-quarters of an hour. For self-docking, the dock is divided transversely into two equal portions, each with its own pumping plant, so that either section can be docked by the other portion. A powerful steam capstan is fitted at each end of the top wall to assist in warping vessels into position when lifting or otherwise. It has eight mechanical side shores in addition to the usual accessories for facilitating the rapid handling of vessels, such as bilge shores, roller fenders, rubbing timbers, and bollards. A duplex reciprocating pump, with a capacity of about 100 tons per hour, has a connection to the main drain of the dock, and enables practically the whole of the water to be pumped out of the dock. On the delivery side the pump is connected to a service-pipe, which has connections at intervals for 3-inch delivery hose. The pump is capable of throwing three jets of water to a height of 40 feet. To enable this floating dock to enter the wet dock in which it was to work, the entrance to which is several feet less than the width of the dock, a joint was provided running the whole length of the pontoon. On arrival of the dock in Penarth roads this joint was disconnected, and the separate sections towed into the wet dock, and reconnected, and the necessary attachment made to the quay wall. [Illustration: BOLTED SECTIONAL DOCK LIFTING A VESSEL.]