At Omaha Beach, Captain Miller says no DD Tanks are getting ashore. What are DD tanks?
They were M-4 Sherman tanks designed to float in to the beach. The DD means duplex drive, meaning they had a drive mechanism to propel them through the water as well as on land. The tanks were also equipped with an inflatable skirt to provide buoyancy. These floating tanks had a very low freeboard, however, and could swamp easily in rough seas. That’s exactly what happened at D-Day. Most of the DD Shermans went straight to the bottom when launched, drowning their crews. One battalion, on orders from Rear Admiral Kirk, rode their LCTs right to the beach and unloaded without any difficulty. Of the 29 launched 5000 meters offshore, only two made it to the beach.
