Name I-51 Laid down 6 April 1921, as S22 Launched 29 November 1921 Beam 7.6 m | Ordered 1918 Fiscal Year Struck 1 April 1940 Length 99 m | |
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Completed 20 June 1924, as Submarine 44 Commissioned 1 November 1924, as I-51 | ||
Japanese submarine I-51 (伊号第五一潜水艦, I-gō Dai Gojū-ichi sensuikan) was the lead vessel and prototype of the Kaidai-class submarines of the Imperial Japanese Navy, which served in World War II.
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Background
Following World War I, the Imperial Japanese Navy General Staff began to re-consider submarine warfare as an element of fleet strategy. Before the war, the Japanese Navy regarded submarines as useful only for short-range coastal point defense. However, based on the success of the Imperial German Navy in deployment of long-range cruiser-submarines for commerce raiding Japanese strategists came to realize possibilities for using the weapon for long range reconnaissance, and in a war of attrition against an enemy fleet approaching Japan. Procurement for a large, long-range Japanese submarine was authorized in fiscal 1918 under the Eight-six fleet program, under the designation S22.
Design
Project S22 was based on the latest Royal Navy design, the British K class submarine. Japanese ties to Great Britain via the Anglo-Japanese Alliance were still strong. Project S22 was laid down at Kure Naval Arsenal on 6 April 1921, launched on 29 November 1921 and completed on 20 June 1924.
During construction, the vessel was renamed Submarine No.44 (第四四号潜水艦, Dai-Yonjūyon-go sensuikan), however, on commissioning into the Imperial Japanese Navy, her name was formally registered as I-51.
With a displacement of 1390 tons, I-51 was the largest submarine built in Japan to date. In order to attain a design speed of 23 knots on the surface, and 15 knots submerged, the design required four diesel engines, driving four screws. To accommodate these engines, a double hull design was used, with hulls joined side-by-side forming a sideways figure "8".
As completed, I-51 achieved only 18.4 knots surfaced and 8.4 knots submerged during trials, but had an unrefueled range of 20,000 nautical miles, which was considered remarkable for the time.
Operational history
I-51, despite her various technical achievements, as not regarded as a successful design, largely through problems with her Sulzer diesel engines. The vessel was never assigned to fleet service, but was retained at Kure Naval Arsenal for crew training and as a test bed for various submarine technologies.
In 1931, I-51 was fitted with an aircraft hangar housing a Yokosuka Ro-go Ko-gata floatplane, which could be raised and lowered into the water by a crane. In 1933, this was modified with the addition of an aircraft catapult, making I-51 the forerunner of the Japanese submarine aircraft carriers of World War II.
In 1932, two of her engines and associated shafts were removed, as was her main gun.
I-51 was removed from the navy list on 1 April 1940 and was scrapped in 1941.