Sherman DD (Duplex Drive)

History of Sherman DD (Duplex Drive)

While the American-made M4 Sherman medium tank was not the best main battle tank of WWII (1939-1945), the sheer number available made it a winning tool. This availability makes it a base for other battlefield vehicles, including dedicated tank killers (Sherman Vc "Firefly") and missile delivery platforms (like Sherman "Calliope"). By the end of the war in 1945, more than 50,000 Shermans were completed.

The British Army standardized on the Sherman, moved away from their early "cruiser/infantry tank" theory, and eventually developed their own production line development plan. One of these works became the "Sherman DD", which was part of the "Hobart Fun" series of mission-specific tank developments as a result of the work of British military engineers.

The name "Sherman DD" is derived from the word "Duplex Drive" as the front line for the protection of the amphibious tank program during its development.

The "Swimming Sherman" was created in 1941 at the initiative of engineer Nicholas Straussler to produce an amphibious version of the classic main battle tank, which would soon be in the Allied stockpile standard. The challenge is how to balance and float the heavy mammoth design in the water while maintaining a useful combat capability after the tank has landed. Early work started with the British Tetrarch light tank and eventually progressed to the larger Valentine cruiser tank before committing to the Sherman series.

The Valentine DD tank was also used in warfare along with the Sherman DD.

The Sherman hull was slightly modified by adding a new boat-like hull structure around the existing hull line, for which a collapsible wading grid and a A flotation system consisting of tubes provides the required buoyancy. When not in use, the flotation screen is machined down and around the edges of the tank's hull to allow the tank to be used in normal combat. When water needs to be passed, the wading grille is erected by two on-board inflatable tanks, and the fixed struts are raised to support and fix the grille. The screen rises to a point above the turret roofline to prevent water from pouring off the top and sinking the ship or damaging its delicate barrel components - the freeboard measures about 3 feet, allowing for some latitude, although this limits some Sea State (Sea State 5, approximately 8 to 13 feet of waves, is the absolute maximum recommended).

Propulsion is controlled by two small steerable propeller units mounted on the lower hull aft of the tank, which are lowered for water work and raised for ground travel. Propulsion comes from the tank's standard powertrain.

The crew were given inflatable rafts and breathing apparatus in case the worst happened.

The entire preparation process takes approximately fifteen minutes by trained staff. One of the added benefits of this process is that it can be performed anywhere without the need for external equipment. As a result, many Sherman DD tanks were ready to land on transporters before the beach attack.

After launch, the tank's crew is expected to be around 4 knots at full speed, although this is a particularly vulnerable period for the Sherman DD - vulnerable to current sea conditions and enemy fire aimed at it.

The standard Sherman armament of the 75mm main gun has been retained, plus the .30 caliber coaxial machine gun, giving the tank considerable firepower in amphibious operations - especially considering the troops carrying the corresponding lightly armed transport vehicles The light weapons come from them on land. Sherman crews could clear enemy positions with high-explosive rounds and suppress enemy forces with machine gun fire.

The standard .30 caliber machine gun hull position on the Sherman base MBT has been removed on the Sherman DD tank.

Once the Sherman DD's tracks are allowed to interact with the bottom, usually in water depths of about 5 feet or less, the wading grid is folded, the propellers are raised to improve ground clearance, and the process is done in the traditional way Forward (lowered wading). The screen did not interfere with the inherent travel of the turret at all).

This allowed the armor to attack enemy beach positions, which surprised defenders and fought alongside Allied infantry units to clear bridgeheads.

This approach proved normal in the successful but ultimately costly D-Day landings in northern France on June 6, 1944. Omaha Beach, in particular, became a grueling event after many expected Sherman DD tanks were lost as they approached in fairway waters - with waves up to 2 meters on the day. Sherman DD tanks were then used in raids on southern France during Operation Dragoon on 15 August 1944.

The vehicles remained in use until 1945 - their last operation was across the Elbe at the end of April. Both Sherman DD and Valentine DD tanks were used in the campaign to retake Italy. Sherman DD tanks were used by British and American troops during the war.

Modified various Sherman models for amphibious tank roles - including M4A1, M4A2 and M4A4 types. Few survive today as exhibits and can be found all over the world.

Specification

Basic

Roles

Dimensions

Performance

Performance

for everyone else in our database)

Armor

90x75mm projectile.

4,500 x .30 caliber ammunition.

Changes