By 1938, sloop trials had given the Royal Navy practical evidence about the minimum useful oceanic ASW escort. Admiral Henderson used those results to select a suitable merchant hull as the basis for a corvette with a single shaft and propeller. Industry helped develop the design, which followed civilian standards as closely as the Navy was prepared to accept and carried no torpedoes. Available guns and, ideally, a large supply of depth charges would provide its armament. The Flower-class orders followed in 1939 before the war began, linking wartime escort production to prewar experimentation.
Notable Point · 31:18-32:09
How merchant standards made the Flower class scalable
Interwar sloop trials let Admiral Henderson specify a single-screw, merchant-standard ASW escort that British industry could build in numbers before war began.