Merchant aircraft carrier

A merchant aircraft carrier (also known as a MAC ship, the Admiralty's official 'short name') was a limited-purpose aircraft carrier operated under British and Dutch civilian registry during World War II. MAC ships were adapted by adding a flight deck to a bulk grain ship or oil tanker enabling it to operate anti-submarine aircraft in support of Allied convoys during the Battle of the Atlantic. Despite their quasi-military function, MAC ships retained their mercantile status, continued to carry cargo and operated under civilian command. MAC ships entered service from May 1943 when they began to supplement and supplant escort carriers, and remained operational until the end of the war in Europe. In 1940, Captain M. S. Slattery RN, Director of Air Material at the Admiralty, proposed a scheme for converting merchant ships into aircraft carriers as a follow-up to the CAM ship project. Slattery proposed fitting a flight deck equipped with two arrester wires and a safety barrier onto an existing merchant ship hull. The resulting 'auxiliary fighter carrier' would be capable of operating six Hurricane fighters while retaining its cargo-carrying ability. The stumbling block for Slattery's proposal turned out to be objections from the Ministry of Supply that combining the merchant and aircraft carrier roles would be too complicated. While this would turn out to be over-stated, it seems to have had the effect of diverting attention away from the idea of hybrid merchant-warships towards the alternative of converting merchant ships into fully-fledged warships designated 'auxiliary aircraft carriers', the first of which, converted from the captured German cargo ship Hannover, entered service as Empire Audacity (later ) in June 1941. The hybrid concept re-emerged early in 1942 when, in the face of mounting losses from U-boat attacks, it became apparent that escort carriers building in the US could not be delivered quickly enough in the numbers required. Various people have been credited with re-inventing the idea, including Captain B.