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M4A2 Sherman III Duplex Drive "Donald Duck" tank

History, technical details and pictures

Image :  M4A2 Sherman III Duplex Drive "Donald Duck" tank

Duplex Drive tank history

In order to provide rapid and effective support to the infantry as part of an amphibious operation or a river crossing, the U.S. military wanted to be equipped with an armored vehicle able to go out of water independently.

U.S. military engineers thought then to create a waterproof protection surrounding a tank equipped with propellers, so that the armored vehicle could fleet. They adapt this technique to the structure of a M4A2 Sherman III tank.

The floating protection up and once in water, the propellers of the tank are initiated and the armored vehicle can reach 4 knots in calm weather. This tank, called Duplex Drive, bears the initials DD. The American and British military have soon nicknamed the tank "Donald Duck" in connection with these initials.

Lorsque le char Sherman DD atteint un rivage, la juppe flottante est abaissée et le blindé retrouve ses propriétés terrestres et peut ainsi appuyer l'infanterie au plus près lors d'un débarquement ou d'un franchissement de fleuve. When the Sherman DD tank reached a shoreline, the floating protection was lowered and the tank could support the infantry during a landing or a river crossing.

Used during the landing at Normandy and the Rhine crossings, the Duplex Drive tank provided a beachhead with a high fire power, without using external means (ships, bridges ...) that could complicate operations.

But the Sherman Duplex Drive could not navigate easily on a rough sea and during the Normandy landings most equipment deployed on Omaha Beach sank, sometimes with their crew.

The Sherman "Crab" tank is one of the "Funnies", a nickname given to the armored vehicles invented by the British engineer Percy Hobbart.


Duplex Drive tank sheet

Country creator/user: USA
Name: M4A2 Sherman III DD ("Duplex Drive")

Length: 5,92 m
Width: 2,62 m
Height: 2,74 m
Weight: 31 800 kg

Maximum speed on land: 34 km/h
Maximum speed at sea: 4 knots

Range: 160 km

Main gun: M3 75 mm gun
Secondary armament: one 7,62 mm Browning machine gun for the copilote and one coaxial 7,62 mm Browning machine gun, one 12,7 mm Browning anti-aircraft machine gun

Engine: GM 6046 diesel engine, 410 hp
Consumption: 279 liters for 100 kilometers

Crew: 5 (1 tank commander, 1 pilote, 1 co-pilote and gunner, 1 radio operator and loader)

Shield: 50 mm front, 38 mm rear, 38 mm sides
Turret shield: 75 mm front, 50 mm rear, 50 mm sides - Reproduction is submitted to authorization - Contact the webmaster