Mark II version of the DD Sherman. The screen was extended and strengthened by fixing to the turret, a new type of bilge pump fitted and a second set of hydraulic steering controls was fitted at the commander's station, although his tiller was retained. An air compressor replaced the air cylinders that provided the pressurized air to erect the screen. After D-Day, US Army interest decreased, looking for other options. While the US Army in Europe used the Sherman DD design, in the Pacific LVTs were equipped with armor and guns to support landings up to the sea line; from the sea line, tanks were supposed to support infantry. Later flotation screen use Designs were made to give the Cromwell and Churchill the DD treatment, but these were never completed. A floating, flame-thrower equipped version of the Universal Carrier was tested, as was a flamethrower-equipped DD Sherman. This towed an armoured fuel trailer, like those used by the Churchill Crocodile. The trailer, in the water, was supported by an inflatable flotation device. After the war, the Centurion was tested with a flotation screen and duplex drive. By the end of the 1950s, development of DD tanks had ceased, partly because main battle tanks were becoming too heavy to be practically made to swim – although experiments were carried-out in the mid-1960s with a floating Centurion that used a similar system, but with rigid panels instead of a flexible screen. The 38 tonne Vickers MBT was fitted with a flotation screen that allowed it to swim. Medium and light vehicles continued to be made amphibious by the use of flotation screens into the 1980s, but without the DD. Instead, they used the movement of their standard running gear (e.g. tracks) for water propulsion also. These included the Swedish Stridsvagn 103 (S-Tank), the American M551 Sheridan light tank, the British FV432 Armoured personnel carrier, the Mark IV version of the Ferret armoured car and early versions of the American M2 Bradley Infantry Fighting Vehicle. Of these, only the FV432 and the Bradley remain in service and current versions lack flotation screens. Combat The main use of DD tanks occurred on D-Day. They were also used in Operation Dragoon, the Allied invasion of southern France on 15 August 1944; Operation Plunder, the British crossing of the Rhine on 23 March 1945 and in several operations on the Italian Front in 1945. DD Tanks