In the Royal Navy
, the designation given to merchant ship
s (usually reasonably fast passenger liners) which during both World Wars were fitted out with a light gun armament and given naval crews to make up for warship shortages. Their primary use was for patrol duties and as escorts for convoy
s against German surface raider
s (themselves often converted merchantmen); they were of no particular value against the much greater submarine
threat and in any fight their high silhouettes and their lack of naval damage control systems and armour made them vulnerable targets. After about 1942 a more fruitful use was made of converted merchant ships as escort carriers
Two AMCs met spectacular ends in heroic but hopeless fights during World War 2; HMS Rawalpindi encountered the German battleships Scharnhorst and Gneisenau - the two most powerful ships in the German fleet at the time - while on patrol in the Denmark Strait in 1939, while in 1940 the Jervis Bay, acting as sole escort to convoy HX 84, sacrificed itself to allow the convoy to scatter by charging the pocket battleship Admiral Scheer.