A 24-inch torpedo is heavy enough that moving and reloading it imposes machinery and crew demands beyond those of a 21-inch weapon. Japanese practice provides the comparison: large torpedoes made autoloading and other support systems part of ship design. Sea Slug loading teams in the 1960s provide a later Royal Navy example because their crews still had to move substantial missile weight by hand. Larger cruisers have more space and displacement for support machinery, which makes a 24-inch weapon more plausible on a Town-class cruiser than on a destroyer. The extra torpedo volume can carry more fuel and power rather than more explosive, extending range while retaining a large warhead. A navy choosing the larger calibre also has to provide room and manpower for storage, movement, launching, and reloading.
Notable Point · 32:32-36:02
Heavy torpedoes demand handling and reloading machinery
Weight, manpower, and reload machinery may explain why 24-inch torpedoes suit larger cruisers better than destroyers, despite their greater range and hitting power.