In this account, the Black Swan further enlarged the Bittern hull, although the class is often described as a lengthened Egret. That lineage connects it to repeated Royal Navy investment in purpose-built anti-submarine sloops before the war. Accumulated design experience underpinned the ships' wartime effectiveness. The class could therefore enter service as an unusually capable escort type when demand became urgent.
Notable Point · 8:16-8:55
From Bittern and Egret to the Black Swan
The Black Swan appears as the mature result of a pre-war sloop lineage rather than an isolated wartime escort design.