Sherman II DD is a British Tank unit.
The ubiquitous M4 Sherman medium tank evolved from the M3 Lee medium tank pressed into service as a stop-gap model in 1941. Designed by the U.S. Army Ordnance Department, the tank built upon proven technologies developed for American tanks of the 1930s, combining them with British experiences in tank design. The result was a versatile, reliable, and cheap tank much like the Soviet T-34.
The M4 entered service in late 1942, outperforming its older sibling in every aspect, the Sherman went on to become one of the most widely produced armored fighting vehicles of World War II. It was well armored, relatively fast, and cheap to produce, becoming the backbone of Allied armored divisions across the world and a major element of the Lend-Lease program for the Soviet Union. Nearly 50 000 tanks were produced before production ended in 1945 and were used across the world.
The M4A1 sub-designation indicates a Sherman model manufactured with a fully cast upper hull, a standard Continental R975 radial engine, and a 75mm medium-velocity general-purpose gun. Sherman II is a British designation for a Lend-Lease M4A1.
The DD stands for Duplex Drive (or Donald Duck among troops), indicating a Sherman fitted with a flotation screen and a propeller, allowing it to cross water barriers. DD tanks primarily served during D-Day operations, but a number of them were later used in Western Europe for river crossings.
During the Normandy Landing, 1st SSB was supported by 13th/18th Royal Hussars. The 13th/18th Royal Hussars was equipped with two DD Tank Squadrons each with 20 Sherman DD. The Squadron HQ had four Sherman DD along with four troops of four more DD. The third Armored Squadron had normal Shermans.