The T-class could fire a large spread because an ambushing boat was unlikely to get a second shot at a fast-moving force. A single torpedo might fail even against a destroyer if it missed a critical area, as HMS Eskimo demonstrated, while a battleship could require several hits. An optimistic 30 percent hit rate explains why ten torpedoes might be needed to secure three hits. A sinking was unnecessary if damage to propulsion or steering imposed a mission kill, detached escorts, and forced the enemy into the kind of operational tradeoff seen at the Battle of Cape Matapan.
Notable Point · 12:14-15:10
The logic of a large torpedo salvo
A large opening salvo gave an ambushing submarine its best chance to damage a warship badly enough to disrupt the whole enemy force.