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.