 As the frigate was intended purely for convoy duties, and not to deploy with the fleet, it had limited range and speed.The contemporary German "Flottenbegleiter" ("fleet escorts"), also known as "F-Boats", were essentially frigates.They were based on a pre-war "Oberkommando der Marine" concept of vessels which could fill roles such as fast minesweeper, minelayer, merchant escort and anti-submarine vessel.