Imperial Japanese Navy submarines

Imperial Japanese Navy submarines originate with the purchase of five Holland type submarines from the United States in 1905. Japanese submarine forces progressively built up strength and expertise, becoming by the beginning of World War II one of the most varied and powerful fleets of submarines of the world.

Origins

The Imperial Japanese Navy acquired its first submarines in 1905 from the relatively new American company, Electric Boat, although the United States Government was officially neutral during Japan's war with Russia during that time.

The ships that Electric Boat sold to Japan were Holland designs, known as Holland Type VIIs and modeled after the American sclass|Plunger|submarine|1s. They were shipped by freighter from Seattle, Washington in "knocked-down" kit form to Japan, and then reassembled by Arthur Leopold Busch at the Yokosuka Naval Arsenal, which was then Japan's largest naval shipyard, to become Hulls No. 1 through 5. These five submarines were originally built at Fore River Ship and Engine Company in Quincy, Massachusetts under Busch's direction for the Electric Boat Company back in August-October 1904.

Frank Taylor Cable, an electrician who was working for Isaac Rice's Electro-Dynamic and Storage Companies along with Rice's Electric Boat, arrived some six months after Busch, training the IJN in the operation of such craft.

The Kawasaki Dockyard Company also bought plans of an improved version directly from Holland, and built two ships (Hulls No. 6 and 7), with the help of two American engineers, Chase and Herbert, who had been assistants to Holland.

Although the capabilities of these first ships actually proved disappointing (and were of no help in the Russo-Japanese War), the first submarine squadron was soon formed at Kure Naval Base in the Inland Sea. In 1909, the first submarine tender, "Toyorasi", was commissioned.

German submarine successes in the Northern Atlantic during the First World War further reinforced Japan's willingness to develop this weapon. Eighteen ocean-going submarines were included in the 1917 expansion program. At the end of the war, Japan also received nine German submarines as reparations, which allowed her to accelerate her technological development during the interwar period.

World War II

Imperial Japanese Navy submarines formed by far the most varied fleet of submarines of World War II, including manned torpedoes ("Kaiten"), midget submarines ("Ko-hyoteki", "Kairyu"), medium-range submarines, purpose-built supply submarines (many for use by the Imperial Japanese Army), fleet submarines (many of which carried an aircraft), submarines with the highest submerged speeds of the conflict ("Sentaka I-200"), and submarines able to carry multiple bombers (WWII's largest submarine, the "Sentoku I-400"). They were also equipped with the most advanced torpedo of the conflict, the oxygen-fuelled Type 95. A plane from one such fleet submarine, "I-25", conducted what is still the only bombing attack on the continental United States, when Warrant Flying Officer Nobuo Fujita attempted to start massive forest fires in the Pacific Northwest outside the town of Brookings, Oregon on September 9th, 1942. In February 1942 the submarine "I-17" launched a number of artillery shells at the Elwood Oil Fields near Santa Barbara, California. None of the shells caused any damage.

Overall, despite their technical innovation, Japanese submarines were relatively unsuccessful. Due to IJN's adherence to a flawed Mahanian doctrine, they were used in offensive roles against warships, which were fast, maneuverable and well-defended compared to merchant ships. In 1942, Japanese submarines managed to sink two fleet carriers, one cruiser, and a few destroyers and other warships, and damage several others. However, these are mostly considered incidental successes that the Japanese were unable to maintain in subsequent years, due to limited resources in the US Navy at the time. Once the US was able to ramp up construction of destroyers and destroyer escorts, as well as bringing over highly effective anti-submarine techniques learned from the British from experiences in the Battle of the Atlantic, they would take a significant toll on Japanese submarines, which tended to be slower and could not dive as deep as their German counterparts. Japanese submarines, in particular, never menaced the Allied merchant convoys and strategic shipping lanes to any degree that German U-boats did.

By the end of the war, submarines were instead often used to transport supplies to island garrisons. During the war, Japan managed to sink about 1 million tons of merchant shipping (184 ships), compared to 1.5 million tons for Great Britain (493 ships), 5.2 million tons for the U.S. (1314 ships), [Blair, "Silent Victory", p.878] and 14.3 million tons for Germany (2,840 ships).

Early models were not very maneuverable under water, could not dive very deep, and lacked radar. (Later in the war units that were fitted with radar were in some instances sunk due to the ability of US radar sets to detect their emissions. For example, USS|Batfish|SS-310|6 sank three such equipped submarines in the span of four days). After the end of the conflict, several of Japan's most original submarines were sent to Hawaii for inspection in "Operation Road's End" ("I-400", "I-401", "I-201", and "I-203") before being scuttled by the US Navy in 1946 when the Soviets demanded to have access to the submarines as well.

ubmarine aircraft carriers

The Japanese applied the concept of the "submarine aircraft carrier" extensively. Altogether 47 submarines were built with the capability to carry seaplanes. Most IJN submarine aircraft carriers could carry only one aircraft, but "I-14" had hangar space for two, and the giant "I-400" class three.

Yanagi missions

These were missions enabled under the Axis Powers' Tripartite Pact to provide for an exchange of strategic materials and manufactured goods between Germany, Italy and Japan. Initially, cargo ships made the exchanges, but when this was no longer possible, submarines were used.

Only six submarines attempted this trans-oceanic voyage during World War II: "I-30" (April 1942), "I-8" (June 1943), "I-34" (October 1943), "I-29" (November 1943), and German submarine "U-511" (August 1943). Of these, "I-30" was partially successful but was later sunk by a mine, "I-8" completed her mission, "I-34" was sunk by British submarine HMS|Taurus|P399|2, and "I-29" by the United States submarine, USS|Sawfish|SS-276|2 (assisted by Ultra intelligence). "I-52" made the final attempt.

1st Class submarines

This class includes the largest of Japanese submarines, characterized by great size and range.

B1 Type (20 units)

B1 Type ("I-15" Series) submarines ("I-15", "I-17", "I-19", "I-21", "I-23", "I-25", "I-26", "I-27", "I-28", "I-29", "I-30", I-31, I-32, I-33, I-34, I-35, I-36, I-37, I-38, I-39) were the most numerous type of submarines of the Imperial Japanese Navy during World War II. In total 20 were made, starting with "I-15", the class ship. These were fast, very long ranged, and carried a single Yokosuka E14Y seaplane, located in a hangar in front of the conning tower, launched by a catapult.

The series was rather successful, especially at the beginning of the war. "I-26", in 1942, crippled aircraft carrier USS|Saratoga|CV-3|6. "I-19", on 15 September 1942, fired six torpedoes at aircraft carrier USS|Wasp|CV-7|6, two of which hit the carrier and sank her, the remainder damaging battleship USS|North Carolina|BB-55|6. "I-25" conducted the only aerial bombings ever on the continental United States in September 1942. Several of these ships also undertook "Yanagi" missions to Europe ("I-30", "I-34", "I-29").

B3 Type

*"I-56" - possibly sank the USS|Snook|SS-279|6 [http://www.aimm.museum/SS-279/ss-279.htm] sometime after April 8, 1945. The I-56 was herself later sunk April 18, 1945 by USS|Collett|DD-730|6. [ [http://www.usscollett.com/history/s_michaelson/command%20history%201.htm WESTPAC Deployment 1966-1968 ] ]
*"I-58" - sank the USS|Indianapolis|CA-35|6 July 30, 1945

AM Type (I-13,I-14)

The AM (A Modified) type was a large seaplane-carrying submarine, with hangar space for two aircraft. These giant submarines were originally of the A2 type, but their design was revised after construction started to carry a second aircraft. The seaplanes were to be the Aichi M6A1 bomber carrying 800 kg bombs.

The range and speed of these submarines was remarkable (21,000 nmi at 16 knots), but their underwater performance was compromised, making them easy targets. "I-13" was sunk on 16 July 1945 by the destroyer escort USS|Lawrence C. Taylor|DE-415|6 and aircraft action from escort carrier USS|Anzio|CVE-57|6 about convert|550|mi|km east of Yokosuka. "I-14" surrendered at sea at the end of the war, and was later scrapped.

C3 Type (I-52, I-53, I-55)

C3 type submarines were submarines of the Imperial Japanese Navy, designed and built by Mitsubishi Corporation, between 1943 and 1944, as cargo carriers. They were quite long and carried a crew of up to 94 persons. They also had a long cruising range at a speed of convert|12|kn|km/h.

The Japanese constructed only three of these during World War II ("I-52", "I-53" and "I-55"), although twenty were planned. They were among the largest submarines ever built to date, and were known as the most advanced submarines of the period.Fact|date=February 2007 One of them, "I-52", was selected for a Yanagi (exchange) mission to Germany. She was sunk on 24 June 1944 by aircraft from USS|Bogue|CVE-9|6 convert|800|mi|km southwest of the Azores. Her cargo consisted of rubber, gold, quinine, and Japanese engineers to Germany.

entoku Type (I-400, I-401, I-402)

The Sentouku (伊四〇〇型潜水艦) "I-400" class displaced 5223 tons surfaced and measured 400 ft 3 in (122m) overall. They had a figure-eight hull shape for additional strength to handle the on-deck hangar for housing the three "Seiran" aircraft. In addition, they had four anti-aircraft guns and a large deck cannon as well as eight torpedo tubes from which they could fire the 21 inch (53cm) Type 95 torpedo.

Three of the "Sen Toku" were built ("I-400", "I-401", and "I-402"). Each had four 1825 horsepower (1360 kW) [Fitzsimons, Bernard, ed. "I-400", "Encyclopedia of Twentieth Century Weapons and Warfare" (London: Phoebux, 1978), Volume 13, p.1415.] engines and range 37,500 nm at convert|14|kn|km/h. ["ibid."]

The submarines were also able to carry three Aichi M6A "Sei ran" aircraft, each carrying an 800 kilogram (1764 lb) bomb convert|550|nmi|km at 360 miles per hour (580 km/h). To fit the aircraft in the hangar the wings of the aircraft were folded back, the horizontal stabilizers folded down, and the top of the vertical stabilizer folded over so the overall profile of the aircraft was within the diameter of its propeller. A crew of four could prepare and get all three airborne in 45 minutes launching them with a 120 foot (37 m) catapult on the fore deck of the giant submarine.

entaka Type (3 units)

The Sentaka Type (潜高 I-200 class) submarines were modern design, and known as "Sentaka" (From "Sen", abbreviation of "Sensuikan", "Submarine", and "Taka", abbreviation of "Kōsoku", "High speed"). Three were built, "I-201", "I-202", and "I-203" ("I-204" to "I-208" were not completed).

They displaced 1070 tonnes, had a test depth of convert|360|ft|m, and were armed with four torpedo tubes and 25 mm guns in retractable mounts to maintain streamlining. These submarines were designed for mass production. They were high-performance boats, with streamlined all-welded hulls and a high battery capacity supplying two convert|2500|hp|abbr=on motors, which had nearly double the horsepower of the German-designed MAN diesels. The submerged speed was convert|19|kn|km/h, more than double that achieved by contemporary American designs. They were equipped with a snorkel, allowing for underwater diesel operation while recharging batteries.

2nd Class submarines

These submarines included medium-sized medium-ranged units of the Imperial Japanese Navy.

Kaichu Type (20 units)

The Kaichus were double-hulled medium sized submarines. They were derived from the Kaitokuchu type submarine (KT). Several variants existed. From 1934 to 1944, the K5 type (RO-33 Class) and the K6 type (RO-35 Class) were built. The K6 type was equipped with a 3.25 inch (80 mm) gun and Type 95 Long Lance torpedoes. 20 units were built: RO-33, RO-34, RO-35, RO-36, RO-37, RO-38, RO-39, RO-40, RO-41, RO-42, RO-43, RO-44, RO-45, RO-46, RO-47, RO-48, RO-49, RO-50 , RO-55, RO-56.

Kaidai class submarine

3rd Class submarines

This class includes the smallest of the Japanese submarines, particularly midget types down to kamikaze manned torpedoes.

Ko-Hyoteki Type (50 units)

The Ko-hyoteki (甲標的, "Type 'A' Target") class of Japanese midget submarines had hull numbers but no names. For simplicity, they are most often referred to by the hull number of the mother submarine. Thus, the midget carried by "I-16" was known as the I-16 midget. The midget submarine hull numbers beginning with the character "HA", which can only be seen on a builder's plate inside the hull.

Fifty were built. The "A Target" name was assigned as a ruse - if their design was prematurely discovered by Japan's foes, the Japanese Navy could insist that the vessels were battle practice targets. They were also called "tubes" and other slang names.

Kairyu Type (250 units)

The Kairyu (海龍 "Sea Dragon") was a class of Kamikaze midget submarines designed in 1943-1944, and produced from the beginning of 1945. These submarines were meant to meet the invading American Naval forces upon their anticipated approach of Tokyo.

Over 760 of these submarines were planned, and by August 1945, 250 had been manufactured, most of them at the Yokosuka shipyard.

These submarines had a two-man crew and were fitted with an internal warhead for suicide missions.

Kaiten Type (1000 units)

The Kaiten (Japanese:回天) was a torpedo modified as a suicide weapon, and used by the Imperial Japanese Navy in the final stages of the Second World War. "Kaiten" means "turning of the heavens".

Early designs allowed for the pilot to escape after the final acceleration towards the target, although whether this could have been done successfully is doubtful. There is no record of any pilot attempting to escape or intending to do so, and this provision was dropped from later production kaitens.

Five models were designed, the Types 1, 2, 3 and 4 based on the Type 93 torpedo (24 inch oxygen/kerosene), and the Type 10, based on the Type 92 torpedo (21 inch electric). Types 2, 4 and 10 were manufactured in small numbers and never used. Prototypes of the Type 3 may have been built, or it may have existed only as a concept.

References

;Notes;Bibliography
* Richard Knowles Morris PhD, "Who Built Those Subs?", Naval History Magazine, United States Naval Institute Press, October 1998, 125th Anniversary Issue.
* "International Directory of Company Histories", Volume 86. Published July 2007. Gale Group/St. James Press.
* "The Klaxon", official U.S. Navy submarine force newsletter. Published by the "Nautilus Memorial Force Library Force Library and Museum", Summer issue, 1992. Account of Arthur Busch/Du Busc's key role pioneering America's first submarines for John Philip Holland - and the first five Imperial Japanese Naval Submarines on behalf of the newly formed Electric Boat Company.

External links

* [http://www.navy.mil/navydata/cno/n87/history/pioneers.html Submarine Pioneers]