Although the Royal Navy had the Landing Craft Mechanised at its disposal, in 1940, Prime Minister Winston Churchill demanded an amphibious vessel capable of landing at least three 36-ton heavy tanks directly onto a beach, able to sustain itself at sea for at least a week, and inexpensive and easy to build. Admiral Maund, Director of the Inter-Service Training and Development Centre (which had developed the Landing Craft Assault), gave the job to naval architect Sir Roland Baker, who within three days completed initial drawings for a landing craft with a beam and a shallow draft. Ship builders Fairfields and John Brown agreed to work out details for the design under the guidance of the Admiralty Experimental Works at Haslar. Tank tests with models soon determined the characteristics of the craft, indicating that it would make on engines delivering about . Designated the LCT Mark 1, 20 were ordered in July 1940 and a further 10 in October 1940.