I-48 was the last of three Type C cruiser submarines of the C2 sub-class built for the Imperial Japanese Navy. Commissioned in September 1944, she operated as a kaiten manned suicide attack torpedo carrier during World War II and was sunk in January 1945. Design and description The Type C submarines were derived from the earlier KD6 sub-class of the with a heavier torpedo armament for long-range attacks. They displaced surfaced and submerged. The submarines were long, had a beam of and a draft of . They had a diving depth of . For surface running, the boats were powered by two diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a electric motor. They could reach on the surface and underwater. On the surface, the C1s had a range of at ; submerged, they had a range of at . The boats were armed with eight internal bow torpedo tubes and carried a total of 20 torpedoes. They were also armed with a single /40 deck gun and two single or twin mounts for Type 96 anti-aircraft guns. They were equipped to carry one Type A midget submarine aft of the conning tower. Construction and commissioning Ordered under the Rapid Naval Armaments Supplement Programme and built by the Sasebo Naval Arsenal at Sasebo, Japan, I-48 was laid down on 19 June 1943 with the name Submarine No. 378. On 12 December 1943 she was numbered I-48 and Launched. She was completed and commissioned on 5 September 1944. Service history Upon commissioning, I-48 was attached to the Yokosuka Naval District and assigned to Submarine Squadron 11 in the 6th Fleet. She was configured to carry four kaiten manned suicide attack torpedoes on her after deck, two of them with access tubes that allowed their pilots to enter them while she was submerged. On 7 December 1944 she was reassigned to Submarine Division 15 in the 6th Fleet, and on 8 December she was assigned to the Kongo ("Steel") kaiten unit. I-48 completed work-ups in the Seto Inland Sea on 26 December 1944 and proceeded to the naval base at Otsujima. She embarked her kaitens and their pilots there, and on 9 January 1945 became the last submarine of the Kongo unit to get underway for the U.S. naval base at Ulithi Atoll in the Caroline Islands to participate in a kaiten attack on the U.S.