Convoy ASW and fleet ASW required different escorts

The persistent, long-range work of a convoy escort differed from the demands on a faster, more heavily armed ship assigned to a battle fleet. A convoy ship needed reliability and endurance through an Atlantic crossing, while a fleet escort also needed speed, guns, air defence, and sometimes torpedoes. Anti-submarine attack favoured manoeuvrability because a submarine could turn sharply during the attack run. It also increasingly demanded weapons projected ahead of the ship so the escort would not lose contact while passing over its target. Mission requirements prevented one destroyer design from serving every role equally well.