DD Tank - "T-6 Device"

"T-6 Device"

An alternative to the DD was the "T-6 Device", developed by the US Army. Limited numbers of the "T-6 Device" were used by the US Army and Marines during Landings at Okinawa. Battle of Okinawa The "T-6 Device" kit consisted of a structure of box-like, pressed-steel floats (pontoons) mounted on the front, rear and sides of a Sherman. Propulsion was provided by the rotation of the tracks. No propellers. The front and rear floats were discarded on the beach, some in the water. Explosive bolts were used. Side floats were removed from the tanks on shore when the tactical situation permitted. In an oral interview with former Pvt. Maurice Dean Derby 37699146, Browning Automatic Rifleman, Co. A, 17th Infantry Regiment, 7th Infantry Division, He related that "On the night of the landing (Okinawa, April 1, 1945) we were kept awake all night because the Tank Crews were beating on the pontoons with sledgehamers to remove them from the Tanks" The tanks were Co. B, 711 Tank Battalion.

Compared with the DD, the floats were bulky and harder to stow, limiting the number of tanks that could be carried in a landing craft. The system was more seaworthy however and had the advantage of allowing the Sherman to fire its main gun as it approached the beach. The Sherman's gyroscopic gun stabilization allowed accurate fire even if the tank was being pitched by waves.