How 24-inch torpedoes would reshape submarines

How would conventional 24-inch torpedoes change submarine development?

They would encourage larger boats and mixed armament, creating much more dangerous anti-capital-ship submarines.

A 24-inch weapon would make submarines much more dangerous to capital ships and battle fleets. Existing designs such as the T class might begin with mixed batteries of 24-inch and 18-inch tubes before changing calibre completely. Rival navies would then face pressure to adopt comparable heavy weapons, turning the change into an international torpedo race. Accommodating the larger tubes, weapons, and handling arrangements would make the submarines themselves grow substantially.