Torpedo size versus fleet logistics

Would 21-inch or 24.5-inch torpedoes have become Britain's postwar standard without treaties?

Not universally: aircraft would still favor 18-inch weapons, destroyers 21-inch weapons, and larger types would create costly handling and supply problems.

An 18-inch torpedo is preferred for aerial delivery because the intended belly-flop entry is easier with the smaller weapon. A 21-inch torpedo would suit destroyers, while 24.5-inch weapons create handling and weight problems on smaller ships. Cruisers and capital ships could use their larger crews and cranes to handle the heavier torpedoes, but separate sizes would complicate worldwide supply. Standardizing surface ships on one type and aircraft on another would reduce that burden. An aerial torpedo might be usable in a ship's launcher in an emergency if their diameters were sufficiently similar.