Volume Three - The Pontoon Era - The Engineer article . . .

As the term off-shore implies, the dock is attached to the shore by means of booms which are hinged and pivoted at the dock, and also at the shore ends to permit of the lowering and raising of the dock when vessels are being docked or undocked. Two very powerful sets of pumping machinery are supplied to the dock consisting of four centrifugal pumps and engines manufactured by Messrs. Gwynnes Ltd., of London. Steam is supplied by two large Babcock & Wilcox boilers working at 160 lb. pressure.

The plant is capable of lifting a vessel of 7,000 tons d.w. (dead weight) in the remarkably short time of three-quarters of an hour. For the purpose of self docking, the dock is divided transversely into two equal halves each with its own pumping plant, so that any one section can be docked by the remaining portion, one half being lifted so to speak in the lap of the other.

A powerful steam capstan is fitted at each end of the top wall to assist in working vessels into position when lifting or otherwise. Light, mechanical side shores are supplied for facilitating the rapid handling of vessels during the operation of docking and undocking, such as bilge shores, roller fenders, rubbing timbers and bollards.

A displacement reciprocating pump with a capacity of 100 tons per hour, has been provided. This pump has a connection to the main drain of the dock, which will enable the last drops of water to be pumped out of the dock. There is also a connection to the sea. 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 ft.

To enable the floating dock to enter the wet dock in which it is destined to work, the entrance to which is several feet less than the width of the dock. There is a longitudinal joint running the whole length of the pontoon. When the dock arrived in Penarth Roads, this joint was disconnected and the separate sections towed into the wet dock, and thereafter reconnected, and the attachment to the quay wall completed.

This dock is another good example of the skill of the renowned floating dock builders, Messrs. Swan Hunter & Wigham Richardson of Wallsend-on-Tyne. They have built floating docks of every type, whether for the British Admiralty or for foreign or colonial governments, or for private companies in every quarter of the globe. Last year alone, they built and dispatched no fewer than five floating docks, one of them was the famous 7,000 ton dock for Calloa in Peru, necessitating a towage of 11,000 miles, including the very hazardous passage of the Magellan Straits.' - The Marine Review - [499] [588] - October 1909 - [20170805]