The Arnold Hague database of FS convoys. The FS convoy series ran from the Firth of Forth (Methil) to theThames (Southend) and ran throughout the war from September 1939 to May 1945. The route was protected by defensive mine fields but was vulnerable to attack by U-boat, E-boat, aircraft, enemy mines and even midget submarines (Taber Park, FS. 1753). In addition to the convoy escorts, these convoys were covered by roving Destroyer and Motor Torpedo Boat patrols to intercept German E-boats.