 HMS Trump was one of the group three of T class submarines. She was part of the second batch of the third group to be ordered, in 1941. She was one of a number of boats which had an all-welded hull which increased diving depth to 350 feet (110 m), an increase of 50 feet (15 m). The torpedo armament was the same as the earlier group two, although by the time group three was coming into service it was realised that external torpedo tubes had major problems and affected the streamlining of the boats; the external tubes were abandoned in the following Amphion class submarine. Because of expected use in tropical climates, boats of group three were equipped with freon blowers in order to deal with the increased temperatures.
