The First World War Flower-class sloops combined escort and minesweeping work because submarine-laid mines were then a greater danger than torpedoes. Some also served as Q-ships, showing how the submarine threat changed the duties expected of small warships. In the interwar period the Bittern design supplied a hull and machinery lineage for later sloops and Hunt-class escort destroyers, while its anti-submarine fit became a capability template. The wartime Flowers scaled that package to a single four-inch gun, light machine guns, and forty depth charges before later receiving more charges, Oerlikons, Hedgehog, and a two-pounder. The weapons and the expected submarine threat defined the requirements before William Reed selected the commercial hull that would carry them.
Notable Point · 36:18-39:53
Mine warfare and the Bittern escort template
The First World War Flowers and the interwar Bittern design explain how minesweeping, submarine hunting, and a practical weapons fit converged in the later corvette.