From Wikipedia, the free encyclopedia

Class overview
Name:	Kaidai type submarines • Kaidai I (I-51 class) • Kaidai II (I-152 class) • Kaidai IIIa (I-153 class) • Kaidai IIIb (I-156 class) • Kaidai IV (I-61/I-162 class) • Kaidai V (I-165 class) • Kaidai VIa (I-168 class) • Kaidai VIb (I-174 class) • Kaidai VII (I-176 class)
Builders:	Kure Naval Arsenal Sasebo Naval Arsenal Yokosuka Naval Arsenal Kawasaki Shipbuilding Mitsubishi Heavy Industries
Operators:	Imperial Japanese Navy
Built:	1921-1943
In commission:	1924-1945

The Kaidai type (海大型 ^?) was a type of 1st class submarines operated by the Imperial Japanese Navy before and during World War II. Type name shortened ''Navy Large Type Submarine (海軍式大型潜水艦, Kaigun-shiki Ōgata Sensuikan ^?). All Kaidai class submarines originally had a two digit boat name, from I-51 onwards. On 20 May 1942, all Kaidai submarines were 1 prefixed to their name. For example, I-52 became I-152. Ships will be listed by the three digit boat name if they had one, two digit if they were not granted one or left service before 20 May 1942.

Class variants

Kaidais were divided into seven types and two sub types; Kaidai I - VII

Kaidai I (I-51 class)

I-51 in 1924

Project number S22. The prototype for the class. The sole Kaidai I, I-51, was based on World War I-era German submarines. She was completed in 1924, was refitted with new engines in 1932, and was scrapped in 1941. I-51 never saw combat. ^[1]

• Boat in class

Kaidai II (I-152 class)

I-152

Project number S25. There was only 1 Kaidai II, I-152 was planned under the Eight-six fleet plan together the I-51. She was completed in 1924, used as a training vessel until mid-1942, then struck from service. She was scrapped in 1946.

• Boat in class

Kaidai IIIa/b (I-153 class and I-156 class)

I-158 in 1927

Project number S26 (Kaidai IIIa) and S27 (Kaidai IIIb). The nine Kaidai IIIs were based on earlier designs, but featured a strengthened hull. The "IIIb" types were 40 cm longer, and had a different bow design. All nine boats were constructed between 1927 and 1930. ^[3]

Of the nine Kaidai IIIs, seven survived the war, as they spent much of their time as training vessels. These were scuttled or scrapped shortly after the end of World War II. I-63 was sunk in a collision with I-60 in 1939, the former losing all crew. I-63 was refloated and scrapped in 1940. I-60 was later sunk by HMS Jupiter. ^[3]

• Boats in classes

Kaidai IV (I-61/162 class)

I-164 in 1930

Project number S28. Slightly smaller than her predecessors and with only four torpedo tubes, three Kaidai IVs were constructed between 1929 and 1930; I-61, I-162, and I-164. I-61 was lost in a collision in 1941. I-164 was sunk by USS Triton on 17 May 1942. I-161 survived the war. ^[4]

• Boats in class

Kaidai V (I-165 class)

I-165 in 1932

Project number S29. Three Kaidai Vs were constructed; I-165, I-166, and I-67 were all completed in 1932. The design saw the upgrade of the deck weapon from a 50 cal to a 65 cal dual-purpose gun. The submarine was also slightly wider and taller, with an increased crew complement of 75 and an increased maximum depth of 230 ft (70 m). I-165 was modified in 1945; her gun removed and two Kaiten midget submarines/manned torpedoes. ^[5]

None of the Kaidai Vs survived World War II. I-67 was lost with all 87 crew during an exercise in 1940. I-165 was sunk on 27 June 1945, off the east coast of Saipan. I-166 was sunk by British submarine HMS Telemachus on 17 July 1944, off the coast of Singapore. ^[5]

• Boats in class

Kaidai VIa/b (I-168 class and I-174 class)

I-168 in 1934

Project number S31 (Kaidai VIa) and S34 (Kaidai VIb). They was built in 1931-34 under the Maru 1 Programme and Maru 2 Programme. Constructed over the course of 1934-1938, eight Kaidai VIs were built; I-168, I-169, I-70, I-171, I-172, I-73, I-174, and I-175. At 23 knots, this type had the fastest surface speed for any submarine at the time of construction, although the speed was bettered slightly by later Japanese submarines. I-174 and I-175 were of the Kaidai VIb sub-type. They were 30 cm longer, 25 tons heavier, and were equipped with a 50 cal deck weapon instead of a 65 cal. ^[6]

Kaidai VIs contributed to the sinking of two American aircraft carriers during World War II. The destruction of these submarines also hold some milestones; I-70 was Japan's first major warship casualty in World War II, and the sinking of I-73 represented the first warship kill by a United States Navy submarine in the war. ^[6]

• Boats in classes

Kaidai VII (I-176 class)

I-176 in 1942

Project number S41. The final design in the Kaidai class, ten Kaidai VIIs were ordered in 1939 (I-176, I-177, I-178, I-179, I-180, I-181, I-182, I-183, I-184, and I-185), and were completed over the course of 1942 and 1943. ^[7] They were built in 1939 under the Maru 4 Programme. IJN called New Kaidai (新海大型, Shin Kaidai-gata ^?) unofficially, and intended to replace this type with Kaidai III and Kaidai IV. Instead of possessing some aft-firing torpedo tubes as all other predecessors did, the Kaidai VII's six tubes all faced forward. They had an underwater endurance of 75 days. ^[8]

Seven of the ten Kaidai VIIs were sunk within their first year of operation, and all ten vessels were sunk by October 1944. ^[8]

• Boats in class^[8][7]

Characteristics

Footnotes

1. ^ "Type KD1". Combinedfleet.com - Imperial Japanese Navy Page. http://www.combinedfleet.com/type_kd1.htm. Retrieved 2007-02-20.  
2. ^ 伊号第51潜水艦 (I-Gō Dai-51 Sensuikan ^?). The same shall apply hereinafter.
3. ^ ^{a b} "Type KD3". Combinedfleet.com - Imperial Japanese Navy Page. http://www.combinedfleet.com/type_kd3.htm. Retrieved 2007-02-20.  
4. ^ "Type KD4". Combinedfleet.com - Imperial Japanese Navy Page. http://www.combinedfleet.com/type_kd4.htm. Retrieved 2007-02-20.  
5. ^ ^{a b} "Type KD5". Combinedfleet.com - Imperial Japanese Navy Page. http://www.combinedfleet.com/type_kd5.htm. Retrieved 2007-02-20.  
6. ^ ^{a b} "Type KD6". Combinedfleet.com - Imperial Japanese Navy Page. http://www.combinedfleet.com/type_kd6.htm. Retrieved 2007-02-20.  
7. ^ ^{a b} Smith (1992) pg. 29
8. ^ ^{a b c} "Type KD7". Combinedfleet.com - Imperial Japanese Navy Page. http://www.combinedfleet.com/type_kd7.htm. Retrieved 2007-02-20.  

References

• Smith, A.E. (May 1992) [1991]. Three Minutes of Time - the torpedoing of the Australian Hospital Ship Centaur (Second Printing ed.). Miami: Tasman Press. ISBN 0-646-07631-0.  

Bibliography

• "Rekishi Gunzō". http://rekigun.net/.  , History of Pacific War Vol.17 I-Gō Submarines, Gakken (Japan), January 1998, ISBN 4-05-601767-0
• Rekishi Gunzō, History of Pacific War Vol.63 Documents of IJN submarines and USN submarines, Gakken (Japan), January 2008, ISBN 4-05-605004-2
• Rekishi Gunzō, History of Pacific War Extra, "Perfect guide, The submarines of the Imperial Japanese Forces", Gakken (Japan), March 2005, ISBN 4-05-603890-2
• Model Art Extra No.537, Drawings of Imperial Japanese Naval Vessels Part-3, Model Art Co. Ltd. (Japan), May 1999, Book code 08734-5
• The Maru Special, Japanese Naval Vessels No.37 Japanese Submarines II, Ushio Shobō (Japan), April 1980, Book code 68343-39