operator mv empire macmahon
A merchant aircraft carrier ( also known as a MAC ) was a limited purpose aircraft carrier built on a British hull designed for bulk grain ships and oil tankers . This was adapted by adding a flight deck enabling it to operate anti - submarine aircraft in support of Allied convoys during the Battle of the Atlantic during ___MASK5___ . MV Empire MacMahon was an oil tanker converted to a merchant aircraft carrier or MAC ship . MV Empire MacMahon was built by Swan Hunter , Wallsend under order from the Ministry of War Transport . She entered service as a MAC ship in December 1943 , however only her air crew and the necessary maintenance staff were naval personnel . She was operated by Anglo - Saxon Petroleum Co . She returned to merchant service as an oil tanker in 1946 and renamed Naninia and was eventually scrapped in Hong Kong in 1960 . ___MASK5___ ( often abbreviated to WWII or WW2 ), also known as the Second World War , was a global war that lasted from 1939 to 1945 , although related conflicts began earlier . It involved the vast majority of the world ' s nations  including all of the great powers  eventually forming two opposing military alliances : the Allies and the Axis . It was the most widespread war in history , and directly involved more than 100 million people from over 30 countries . In a state of " total war ", the major participants threw their entire economic , industrial , and scientific capabilities behind the war effort , erasing the distinction between civilian and military resources . Marked by mass deaths of civilians , including the Holocaust ( in which approximately 11 million people were killed ) and the strategic bombing of industrial and population centres ( in which approximately one million were killed , and which included the atomic bombings of Hiroshima and Nagasaki ), it resulted in an estimated 50 million to 85 million fatalities . These made ___MASK5___ the deadliest conflict in human history . The Battle of the Atlantic was the longest continuous military campaign in ___MASK5___ , running from 1939 to the defeat of Germany in 1945 . At its core was the Allied naval blockade of Germany , announced the day after the declaration of war , and Germany ' s subsequent counter - blockade . It was at its height from mid - 1940 through to the end of 1943 . The Battle of the Atlantic pitted U - boats and other warships of the " ___MASK56___ " ( German navy ) and aircraft of the " Luftwaffe " ( German Air Force ) against the Royal Canadian Navy , ___MASK16___ , the United States Navy , and Allied merchant shipping . The convoys , coming mainly from North America and predominantly going to the United Kingdom and the Soviet Union , were protected for the most part by the British and Canadian navies and air forces . These forces were aided by ships and aircraft of the United States from September 13 , 1941 . The Germans were joined by submarines of the Italian ___MASK16___ (" Regia Marina ") after their Axis ally Italy entered the war on June 10 , 1940 .