At the end of the war, most T Class submarines were placed in reserve, taken out of service or ceded to other countries. Most of the early T Class with riveted hulls could not be fully modernized, but five - Tireless, Token and the Barrow-built Tapir, Talent and Teredo - were streamlined and completely refitted with six bow tubes, modern sonar and a fin-shaped conning tower.
In 1951-56, eight of the welded-hull boats were completely rebuilt in a manner similar to the American Greater Underwater Propulsive Power 'Guppy' Programme. The eight converted were: Tabard; Truncheon; Thermopylae; Totem; Turpin and the. Vickers-built Trump, Tiptoe and Taciturn. Their hulls were cut. in two and new sections added to their length. They were
