The first LCT Mark 1 was launched by Hawthorn Leslie in November 1940. It was an all-welded 372-ton steel-hulled vessel that drew only of water at the bow. Sea trials soon proved the Mark 1 to be difficult to handle and almost unmanageable in some sea conditions. The designers set about correcting the faults of the Mark 1 in the LCT Mark 2. Longer and wider, three Paxman diesel or Napier Lion petrol engines replaced the Hall-Scotts, and 15 and 20 lb. armoured shielding was added to the wheelhouse and gun tubs.