Largest Floating Docks

 Large docks are an essential part of a ship repair yard. A dry dock is one that can be drained and refilled. Dry docks are used for construction, for routine maintenance (such as repainting and cleaning the hull), for refitting and refurbishment, for the repair of storm damage, and in the case of naval vessels for the repair of battle damage.

A floating dry dock the advantage of flexibility. It can be moved from site to site to meet demand and can be sold in the second hand market.  But, it is a very expensive asset.

The first reference to a floating dock is in a little Italian book that was printed in Venice in 1560. The booklet contains a woodcut showing a ship accompanied by two large barges. The ship is being pulled in an upright position by a number of ropes that hang from the roof.

Floating docks have great military value.  During the 1920s, when the ability of British shipyards to service the mighty Hood battleship was questioned, the importance of floating facilities was raised in Parliament.  Large German floating docks were used to build and service German pocket battleships.  In wartime these were subject to frequent RAF raids.  In 1941 the US Navy engaged in a massive floating dock building to provide maintenance facilities in remote locations.  Many of these floating docks were designed to be joined end-to-end to accomodate exceptionally long vessels.  When the Second World War drew to a close the fate of the German floating docks was never resolved.  These had fallen into the British zone of occupation.  The British argued that the docks were fixed assets.  The Soviets argued that they were disposable and could be redeployed.

The picture shows the AFDB-3 carrying the USS Idaho at Guam in 1945. This 850-foot dock saw action at  Guam, was mothballed near Norfolk, Virginia, then saw commercial service at the Bath Iron Works’ repair facilities at Portland, Maine before being sold to a Croatian yard in 1999. 

Crandall Dry Dock Engineers Inc was particularly influentual in post war dock design. This company has been over-committed during the Second World War and had missed out on much of the US Navy programme.  The company introduced the first all-steel welded floating dock in 1952.  It then followed up opportunities presented by the Suez crisis in 1956.  The closure of the Suez Canal during the crisis encouraged Japanese shipowners to develop very large oil tankers. Crandall met demand and supplemented obselete facilities with  floating dry docks.