Landing Craft Tank - Development - Mark 5

Mark 5

When the United States entered the war in December 1941, the U.S. Navy had no amphibious vessels at all, and found itself obliged to consider British designs already in existence. One of these, advanced by K.C. Barnaby of Thornycroft, was for a double-ended LCT to work with landing ships. The Bureau of Ships quickly set about drawing up plans for landing craft based on Barnaby's suggestions, although with only one ramp. The result, in early 1942, was the LCT Mark 5, a 117-foot craft with a beam of 32 feet that could accommodate five 30-ton or four 40-ton tanks or 150 tons of cargo. With a crew of twelve men and one officer, this 286 ton landing craft had the merit of being able to be shipped to combat areas in three separate water-tight sections aboard a cargo ship or carried pre-assembled on the flat deck of a LST. The Mk.5 would be launched by heeling the LST on its beam to let the craft slide off its chocks into the sea, or cargo ships could lower each of the three sections into the sea where they were joined together.

Powered by three 225 hp Gray marine diesels, the Mk.5 had a range of only 700 nautical miles (1,300 km; 810 mi). They were only capable of making 8 knots (15 km/h; 9.2 mph) at best; a speed too slow for independent passage across the Pacific. Shipped aboard other vessels, Mk.5s soon proved themselves in operations. Inland yards would lead LCT production and it was not long before yard workers boasted that "they built them by the mile and cut them up in feet". Four hundred and seventy Mk.5s were built.

First used in the invasion of North Africa, the Mk.5 crews immediately earned a reputation for efficiency under fire and in the worst of weather or sea conditions. Enjoying little priority in fleet maintenance schedules, the LCT crews also gained a reputation for "finding" whatever they needed. Much of this lack of status within the amphibious forces was because the LCT was the smallest landing craft organized into independent assault flotillas. Almost entirely manned by reservists and draftees, LCT crews operated in a free and easy manner that horrified professional naval officers. By late 1943, most early Mk.5s were relegated to training or harbor duties in the United States.