Japanese submarine I-55 (1925)

Following World War I, the Imperial Japanese Navy re-evaluated the use of submarine warfare as an element of fleet strategy due to the successful deployment of long-range cruiser submarines for commerce raiding by the Imperial German Navy. Japanese strategists came to realize possibilities for using submarines for long-range reconnaissance and in a war of attrition against an enemy fleet approaching Japan. The Japanese already had built two large, long-range submarines — and I-52 — under the Eight-six fleet program as prototypes, but the arrival on 20 June 1919 of seven German U-boats Japan received as war reparations after the end of World War I led to a complete re-design. The Japanese quickly hired hundreds of German submarine engineers, technicians, and former U-boat officers unemployed after the defeat of the German Empire in World War I and brought them to Japan under five-year contracts. The United States Navy′s Office of Naval Intelligence estimated that some 800 German advisors had gone to Japan by the end of 1920. The Japanese also sent delegations to Germany, and were active in purchasing many patents related to submarine design and construction. ==Design==

The four Kaidai Type 3A submarines were the first mass-produced Japanese fleet submarines. Based largely on the lone Kaidai Type II submarine (I-52), their design was also influenced by the largest of the German submarines in Japanese hands, . Compared with I-52, they a strengthened double hull. The hull had almost the same outer dimensions as that of I-52, but the increased thickness of the inner hull permitted a diving depth of . The internal volume was slightly increased over that of I-52 by making the hull slightly trapezoidal in cross-section at the expense of 300 tons of additional displacement. External differences from I-52 included an anti-submarine net cutter on the bow, as well as an O-ring for towing purposes. The Kaidai Type 3A submarines displaced surfaced and submerged. The submarines were long and had a beam of and a draft of . They had a complement of 60 officers and crewmen. Sulzer was retained as the manufacturer for the diesel engines, which had a slightly improved performance over the engines in I-52. For surface running, the submarines were powered by two diesel engines, each driving one propeller shaft. When submerged, each propeller was driven by a electric motor. The submarines could reach on the surface and submerged. On the surface, the KD3As had a range of at ; submerged, they had a range of at . The submarines had eight internal torpedo tubes, six in the bow and two in the stern. They carried one reload for each tube for a total of 16 torpedoes. They were had one 12 cm 11th Year Type naval gun| deck gun. ==Construction and commissioning==

Built by the Kure Naval Arsenal, I-55 was laid down on 1 April 1924 as . While under construction, she was renamed I-55 on 1 November 1924. She was launched on 2 September 1925 and completed and commissioned on 5 September 1927. ==Service history==

Pre-World War II On the day she was commissioned, I-55 was assigned to the Kure Naval District I-54 reduced speed to , but nonetheless accidentally rammed I-55. departing Takao on 13 July 1933 with the other five submarines and again training in Chinese waters before arriving in Tokyo Bay on 21 August 1933; The cruise concluded with their arrival at Sukumo Bay on 25 February 1935. Submarine Squadron 4 was assigned directly to the Combined Fleet on 15 November 1940. K XII steered to ram the Japanese submarine and had closed to of where lookouts had last seen the periscope when the periscope reappeared to port. I-53, I-54, and I-55 departed Staring Bay on 16 March and arrived at Kure, Japan, on 25 March 1942, and garbled Japanese message intercepted, decrypted, and translated by Allied signals intelligence indicated that her damage included a hole measuring . April 1945–November 1945 On 20 April 1945, I-155 and the submarine were reassigned to Submarine Division 33 in the Kure Submarine Squadron in the Kure Naval District, and by late April 1945 I-155 had been converted to transport kaiten manned suicide attack torpedoes to bases on Shikoku, with her deck gun replaced by fittings for two kaiten. On 20 July 1945, she was placed in reserve and anchored near the Kure Submarine School. In the final days of the war, I-155 was selected for a kaiten mission. Recommissioned in early August 1945, she was fitted with two kaiten at the naval base at Ōzushima and was scheduled to depart Hirao on 25 August 1945 with the submarine as part of the Shinshu-tai ("Land of Gods Unit") kaiten group. Although Emperor Hirohito announced the cessation of hostilities on 15 August 1945, I-155 and I-156 put to sea from Hirao for the operation on 25 August 1945. The kaiten mission was cancelled that day and the submarines were recalled. I-155 proceeded to Kure, where she surrendered to the Allies in September 1945. The Japanese removed her from the Navy list on 20 November 1945. ==Disposal==

I-155 was among 17 captured Japanese submarines sunk by gunfire by the Royal Australian Navy destroyer and the Royal Indian Navy sloop-of-war in the Seto Inland Sea between Honshu and Shikoku on 8 May 1946 in Operation Bottom. ==References==