Valentine DD

The Valentine DD was the first production version of the Duplex Drive (DD) amphibious tank, a conventional Valentine infantry tank made to float by a folding canvas screen. The archive notes give the number converted as 625 or 635.

Development

The problem of making a normal tank swim without adding bulk was solved by Nicholas Straussler's collapsible flotation screen. It was first fitted experimentally to a Tetrarch light tank, which was tried in June 1941 at Brent (Hendon) Reservoir in north London in front of General Alan Brooke. Curiously, this was the same place where a floating Mark IX tank had been tested 23 years earlier. After successful sea trials of the Tetrarch in Portsmouth Harbour, it was decided to put the DD into production on the Valentine, a reliable British tank already in service.

Design

In the Valentine the driver sits centrally and steers with clutches and brakes. The engine, gearbox and transmission are behind the rear bulkhead, driving the rear sprockets through multi-plate steering clutches and side-mounted reduction gears. A No. 19 radio set is carried in the back of the turret.

Service

Most American, British and Canadian DD crews did their initial training on the Valentine DD. By 1944, however, the Valentine was considered past its prime, and the DD principle was applied to the Sherman, which was then in service with all the Allied armies. According to the archive notes, 693 Sherman DDs were built between March 1944 and February 1945, and only about ten survive.