of destroyers could not fire fast enough to deal with this form of attack and the 20 mm Oerlikon cannon did not fire a shell heavy enough to cripple the vessel. A remedy was offered in the form of the twin 6-pounder 10 cwt gun. For naval use, it was mounted in place of No 1 gun (A mount) on four W class destroyers and proved an effective countermeasure. Since the need for greater anti-submarine capability was vital, even on the coastal convoys and the 6-pounder competed for space with the new ahead-throwing Hedgehog anti-submarine mortar, only four standard destroyers,, , and , were fitted with this twin-6-pounder mounting. Along with these four, three of the Admiralty type flotilla leaders, , and , were refitted with the mount. Notes and references Notes Citations Further reading Campbell, John Naval Weapons of World War Two H. T. Lenton and J. J. Colledge, Warships of World War II External links Film of Twin 6 Pounder Coast Artillery gun at practice in Weymouth, 1948 (Pathe) Details of the 6pdr Naval and Coastal Gun by Tony DiGiulian "Playhouses" Rip Invasion Craft With Twin Six-Pounder Gun March 1944 article Westwood Works in World War 2. The Twin 6-pounder Coastal Defence Gun Naval guns of the United Kingdom 57 mm artillery Coastal artillery World War II naval weapons of the United Kingdom Military equipment introduced in the 1930s