British submarine production, the A class, and special-purpose designs

The S, U, and T classes provided the basis for British submarines completed in time for wartime operations. Improvements from combat experience entered those designs as building capacity allowed. Several proposed special-purpose designs were deferred because their advantages did not justify disruption to the construction programme. Work on the A class went ahead from late 1941, with introduction planned for a point when builders could accommodate it. A-class boats were about to be delivered at frequent intervals when the war ended, and they formed the basis of the postwar fleet. Introducing that generation is offered as evidence of continued British naval ambition despite financial strain. X and XE midget submarines and Chariot human torpedoes demanded design effort disproportionate to their size, although the 1947 paper judges that investment worthwhile.