 A small crew of Kriegsmarine sailors trained 48 Japanese sailors at sea from October 1943 to February 1944.After the crew underwent 3 months of training, "U-1224" was recommissioned into the Japanese navy under the pennant "RO-501".Captain Narita was put in charge of the crew, and "RO-501" was then tasked to carry a load of war materials, blueprints, and other secret cargo from Kiel, Germany to Penang, Malaysia.