German aircraft carrier II The aircraft carrier II was a proposed conversion project for the incomplete French cruiser " De Grasse " . The ship was laid down in November 1938 and lay incomplete in the Arsenal de Lorient shipyard when Germany invaded France in May 1940 . In 1942 , the German Kriegsmarine decided to convert the cruiser into an auxiliary aircraft carrier with a capacity for twenty - three fighter s and dive bomber s . Work ceased in February 1943 , however , due to concerns with the ship ' s design , a severe shortage of material and labor , and the threat of Allied bombing raids . The ship was eventually completed as an anti - aircraft cruiser in 1956 by the French Navy . Design . The French cruiser " De Grasse " was laid down at the Arsenal de Lorient shipyard in Lorient in November 1938 . Work on the unfinished ship stopped following the German conquest of France in May 1940 . In 1942 , the German Kriegsmarine considered several proposals to convert the cruiser into an auxiliary aircraft carrier . The final proposal was completed by August 1942 , but work on the conversion did not last long . By February 1943 , the project had been abandoned , for several reasons . The shipyard suffered from a shortage of labor and materials , and the design staff had significant concerns over the arrangement of the engine system . The Allies also posed a serious threat , as Lorient was well within the range of Allied bombers . The ship was eventually retaken by the French Navy after the end of the war , and launched in 1946 . She was ultimately completed in 1956 as an anti - aircraft cruiser . Characteristics . The converted ship would have been long at the waterline and long overall . She would have had a beam of and a draft of as designed . Her designed displacement would have been . The ship ' s propulsion system consisted of two sets of Rateau - Bretagne geared steam turbines , with steam supplied by four Indret ultra - high pressure boilers . The engines were rated at and would have provided a top speed of . The carrier would have had a range of at a cruising speed of . As converted , the ship was to be armed with several anti - aircraft guns . The heavy anti - aircraft battery consisted of twelve SK C / 33 guns in twin mountings . The mounts were the Dopp LC / 31 type , originally designed for earlier SK C / 31 guns . The LC / 31 mounting was triaxially - stabilized and capable of elevating to 80° . This enabled the guns to engage targets up to a ceiling of . Against surface targets , the guns had a maximum range of . The guns fired fixed ammunition weighing ; the guns could fire HE and HE incendiary rounds , as well as illumination shells . Close - range anti - aircraft weaponry consisted of twelve SK C / 30 guns and twenty - four Flak 38 guns . The 3 . 7 cm gun was a single - shot gun , with a rate of fire of around 30 rounds per minute . At its maximum elevation of 85° , the gun had a ceiling of . The 2 cm gun was a magazine - fed automatic weapon , firing at up to 500 rounds per minute . Twenty and forty - round magazines were supplied for the guns ; The ship ' s aircraft facilities consisted of a long , wide flight deck and two elevators . Aircraft were handled in a single hangar , which was long and wide . The ship ' s air complement was to have consisted of eleven Bf 109 fighters and twelve Ju 87 Stuka dive - bombers . The Bf 109 fighters were a navalized version of the " E " model , designated as Bf 109T . Their wings were longer than the land - based model to allow for shorter take - off . The Ju 87s were to have been the " E " variant , which was a navalized version of the Ju 87D , and were modified for catapult launches and were equipped with arresting gear .