The was a type of 1st class submarine operated by the Imperial Japanese Navy

Imperial Japanese Navy

The Imperial Japanese Navy was the navy of the Empire of Japan from 1869 until 1947, when it was dissolved following Japan's constitutional renunciation of the use of force as a means of settling international disputes...

 (IJN) before and during World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

. The type name, was shortened to . All Kaidai class submarines originally had a two digit boat name, from I-51 onwards. On 20 May 1942, all Kaidai submarines added a '1' to their name. For example, I-52 became I-152. Ships are 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)

Project number S22. The prototype for the class. The sole Kaidai I, I-51, was based on World War I

World War I

World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

-era German submarines. She was completed in 1924, refitted with new engines in 1932 and scrapped in 1941. I-51 never saw combat.

• Boat in class

  Boat	Builder	Laid down	Launched	Completed	Fate
  No.44 Submarine I-51	Kure Naval Arsenal	6 April 1921	29 November 1921	20 June 1924	Renamed I-51 on 1 November 1924. Decommissioned on 1 April 1940

Kaidai II (I-152 class)

Project number S25. There was only 1 Kaidai II, I-152 planned under the Eight-six fleet

Eight-eight fleet

The was a Japanese naval strategy formulated for the development of the Imperial Japanese Navy in the first quarter of the 20th century, which laid down that the Japanese navy should include eight first-class battleships and eight armoured cruisers or battlecruisers.-History and development:The...

 together with 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

  Boat	Builder	Laid down	Launched	Completed	Fate
  No.51 Submarine I-52, I-152	Kure Naval Arsenal	14-02-1922	12-06-1923	20-05-1924	Renamed I-52 on 01-11-1924, decommissioned on 01-08-1942, scrapped post-war

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

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.

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 her crew. I-63 was refloated and scrapped in 1940. I-60 was later sunk by HMS Jupiter

HMS Jupiter (F85)

HMS Jupiter was a J-class destroyer of the Royal Navy laid down by Yarrow & Company at Scotstoun in Glasgow on 28 September 1937, launched on 27 October 1938 and commissioned on 25 June 1939.-Operations:...

.

• Boats in classes

  Boat	Sub type	Builder	Laid down	Launched	Completed	Results	Fate
  I-53, I-153	Kaidai IIIa	Kure Naval Arsenal	01-04-1924	05-08-1925	30-03-1927	Sank Dutch merchant ship Mösi on 27-02-1942 Sank RMS City of Manchester on 28-02-1942 Sank unknown merchant vessel on 27-02-1942	Decommissioned on 20-11-1945, scrapped in 1948
  I-54, I-154	Kaidai IIIa	Sasebo Naval Arsenal	15-11-1924	15-03-1926	15-12-1927	Sank Dutch merchant ship Majokaat on 02-03-1942	Decommissioned on 20-11-1945, disposed of at Iyo Nada in May 1946
  I-55, I-155	Kaidai IIIa	Kure Naval Arsenal	01-04-1924	02-09-1925	05-09-1927	Sank Dutch merchant-man Van Lansberge on 04-02-1942 Sank Dutch merchant ship Van Cloon on 07-02-1942 Sank RMS Derrymore on 14-02-1942 Sank Norwegian merchant vessel Madrono on 18-02-1942	Decommissioned on 20-11-1945, disposed of at Iyo Nada in May 1946
  I-56, I-156	Kaidai IIIb	Kure Naval Arsenal	03-11-1926	23-03-1928	31-03-1929	Sank Greek merchant ship Hydra II or Norwegian merchant ship Hai Tung on 11-12-1941 Sank RMS Kuantan on 05-01-1942 Damaged Dutch merchant ship Tanimbar on 06-01-1942 Sank Dutch merchantman Van Rees on 08-01-1942 Sank Dutch merchant ship Van Riebeeck on 08-01-1942 Damaged Dutch merchant ship Patras on 13-01-1942 Sank Dutch merchant ship Togian on 04-02-1942	Decommissioned 30-11-1945, sunk as a target off the Gotō Islands Goto Islands The are Japanese islands in the East China Sea, off the western coast of Kyūshū. The islands are a part of Nagasaki Prefecture.- Geography :There are 140 islands in total, including five main islands:,,,, and....  on 01-04-1946
  I-57, I-157	Kaidai IIIb	Kure Naval Arsenal	08-07-1927	01-10-1928	24-12-1929	Sank Dutch merchant ship Djirak on 07-01-1942	Decommissioned 30-11-1945, sunk as a target off the Gotō Islands on 01-04-1946
  I-58, I-158	Kaidai IIIa	Yokosuka Naval Arsenal	03-12-1924	03-10-1925	15-05-1928	Sank Dutch merchant ship Langkoas on 03-01-1942 Sank Dutch merchant ship Camphuys on 09-01-1942 Sank Dutch merchant vessel Pijnacker Hordijk on 22-02-1942 Sank Dutch merchant ship Boeroe on 25-02-1942 torpedoed but did not sink RMS British Judge on 28-02-1942	Decommissioned on 30-11-1945, sunk as a target off the Gotō Islands on 01-04-1946
  I-59, I-159	Kaidai IIIb	Yokosuka Naval Arsenal	25-03-1927	25-03-1929	31-03-1930	Sank Norwegian merchant ship Eidsvold on 20-01-1942 Sank unknown merchantman 25-01-1942 Sank Dutch merchant ship Rooseboom on 01-03-1942	Decommissioned on 30-11-1945, sunk as a target off the Gotō Islands on 01-04-1946
  I-60	Kaidai IIIb	Sasebo Naval Arsenal	10-10-1927	24-04-1929	20-12-1929		Sunk by HMS Jupiter HMS Jupiter (F85) HMS Jupiter was a J-class destroyer of the Royal Navy laid down by Yarrow & Company at Scotstoun in Glasgow on 28 September 1937, launched on 27 October 1938 and commissioned on 25 June 1939.-Operations:...  in the Sunda Strait Sunda Strait The Sunda Strait is the strait between the Indonesian islands of Java and Sumatra. It connects the Java Sea to the Indian Ocean...  06°00′S 105°00′E on 17 January 1942
  I-63	Kaidai IIIb	Sasebo Naval Arsenal	12-08-1926	28-09-1927	20-12-1928		Lost in an accident in the Bungo Channel Bungo Channel The is a strait separating the Japanese islands of Kyūshū and Shikoku. It connects the Pacific Ocean and Seto Inland Sea. The narrowest part of this channel is the Hōyo Strait....  on 20-02-1939. Salvaged and scrapped on 21-01-1940

Kaidai IV (I-61/162 class)

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

USS Triton (SS-201)

USS Triton , a Tambor-class submarine, was the first submarine and third ship of the United States Navy to be named for Triton. Her keel was down on 5 July 1939 by the Portsmouth Navy Yard. She was launched on 25 March 1940 sponsored by Mrs. Ernest J. King, wife of Rear Admiral King, and...

 on 17 May 1942. I-162 survived the war.

• Boats in class

Boat	Builder	Laid down; Launched; Completed	Results	Fate
I-61	Mitsubishi, Kōbe Shipyard	15-11-1926; 12-11-1927; 06-04-1929		Lost in an accident on 02-10-1941 in the Iki Channel. Raised and BU BU BU may stand for:* Backup* Bus Interface Unit, also called BIU* Brabender Units, used in flour anaylsis* Bethesda unit, a measure of inhibitor activity relating to a coagulation factor...  in 1942
I-62, I-162	Mitsubishi, Kōbe Shipyard	20-04-1927; 29-11-1928; 24-03-1930	• Damaged RMS Longwood 31-01-1942 • Damaged RMS Spondilus on 04-02-1942 • Sank RMS Lakshmi Govinda on 10-03-1942 • Sank Dutch merchant ship Merkus on 16-03-1942 • Damaged RMS San Cirilo on 21-03-1942 • Sank unknown merchant ship on 22-03-1942 • Sank Soviet merchant ship Mikoyan on 03-10-1942 • Sank RMS Manon on 07-10-1942 • Damaged RMS Martaban on 13-10-1942 • Sank RMS Fort McCloud on 03-03-1944	Decommissioned 30-11-1945, sunk as a target off the Gotō Islands on 01-04-1946
I-64, I-164	Kure Naval Arsenal	28-03-1928; 05-10-1929; 30-08-1930	• Sank Dutch merchant vessel Van Overstraten on 22-01-1942 • Damaged RMS Idar on 28-01-1942 • Sank SS Florence Luckenbach on 29-01-1942 • Sank Indian merchant ship Jalatarang on 30-01-1942 • Sank Indian merchant ship Jalapalaka on 31-01-1942 • Sank Norwegian merchant ship Mabella on 13-03-1942	Sunk by USS Triton USS Triton (SS-201) USS Triton , a Tambor-class submarine, was the first submarine and third ship of the United States Navy to be named for Triton. Her keel was down on 5 July 1939 by the Portsmouth Navy Yard. She was launched on 25 March 1940 sponsored by Mrs. Ernest J. King, wife of Rear Admiral King, and...  south of Kyūshū Kyushu is the third largest island of Japan and most southwesterly of its four main islands. Its alternate ancient names include , , and . The historical regional name is referred to Kyushu and its surrounding islands....  29°25′N 134°09′E on 17-05-1942

Kaidai V (I-165 class)

Project number S29. Three Kaidai Vs were constructed; I-165, I-166, and I-67 which 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

Kaiten

The Kaiten were manned torpedos and suicide craft, they were used by the Imperial Japanese Navy in the final stages of World War II.-History:...

 midget submarines/manned torpedoes substituted.

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

Saipan

Saipan is the largest island of the United States Commonwealth of the Northern Mariana Islands , a chain of 15 tropical islands belonging to the Marianas archipelago in the western Pacific Ocean with a total area of . The 2000 census population was 62,392...

. I-166 was sunk by the British submarine HMS Telemachus

HMS Telemachus (P321)

HMS Telemachus was a British submarine of the third group of the T class. She was built as P321 by Vickers Armstrong, Barrow, and launched on 19 June 1943.-Service:...

 on 17 July 1944, off the coast of Singapore

Singapore

Singapore , officially the Republic of Singapore, is a Southeast Asian city-state off the southern tip of the Malay Peninsula, north of the equator. An island country made up of 63 islands, it is separated from Malaysia by the Straits of Johor to its north and from Indonesia's Riau Islands by the...

.

Boat	Builder	Laid down	Launched	Completed	Results	Fate
I-65, I-165	Kure Naval Arsenal	19-12-1929	02-06-1931	01-12-1932	• Sank Dutch merchant ship Benkoelen on 09-01-1942 • Sank Indian merchant ship Jalarajan on 15-01-1942 • Sank Netherlands merchant Johanne Justesen on 15-02-1942 • Sank RMS Bhima on 20-02-1942 • Sank SS Harmonides on 25-08-1942 • Sank USS Losmar on 24-09-1942 • Sank RMS Perseus on 16-01-1944 • Sank SS Nancy Moller on 18-03-1944	Converted to the Kaiten Kaiten The Kaiten were manned torpedos and suicide craft, they were used by the Imperial Japanese Navy in the final stages of World War II.-History:...  mother ship in 1945, sunk by USN patrol bomber in the Mariana Islands Mariana Islands The Mariana Islands are an arc-shaped archipelago made up by the summits of 15 volcanic mountains in the north-western Pacific Ocean between the 12th and 21st parallels north and along the 145th meridian east...  15°28′N 153°39′E on 27-06-1945
I-66, I-166	Sasebo Naval Arsenal	08-11-1929	02-06-1931	10-11-1932	• Sank Dutch submarine K XVI HNLMS K XVI HNLMS K XVI was one of five K XIV class submarines built for the Royal Netherlands Navy . She was ordered from Rotterdam-based shipbuilder Rotterdamsche Droogdok Maatschappij on 30 May 1929, and was laid down on 31 May 1930...  on 25-12-1941 • Sank USS Liberty Glo on 11-01-1942 • Sank Panamanian merchantman Nord 21-01-1942 • Sank RMS Chak Sang on 22-01-1942 • Sank RMS Kamuning 14-02-1942 • Sank Panamanian merchantman Camila on 01-10-1942 • Sank RMS Cranfield on 22-11-1942	Sunk by on 17-07-1945
I-67	Mitsubishi, Kōbe Shipyard	08-11-1929	02-06-1931	10-11-1932		Lost in an accident at Minami Torishima Minami Torishima or Marcus Island is an isolated Japanese coral atoll in the northwestern Pacific Ocean, located some SE of Tokyo and east of the closest Japanese island, South Iwo Jima of the Ogasawara Islands, and nearly on a straight line between Tokyo and Wake Island, which is east southeast...  on 29-08-1940

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

Project number S31 (Kaidai VIa) and S34 (Kaidai VIb). They were built in 1931-34 under the Maru 1 Programme

1st Naval Armaments Supplement Programme (Japan, 1931)

The , otherwise known as the "Circle One" plan was the first of four expansion plans of the Imperial Japanese Navy between 1930 and the start of World War II.-Background:...

 and the Maru 2 Programme

2nd Naval Armaments Supplement Programme (Japan, 1934)

The otherwise known as the "Circle Two" Plan was the second of four expansion plans of the Imperial Japanese Navy between 1930 and the start of World War II.-Background:...

. Constructed between 1934 and 1938, eight Kaidai VIs were built; I-168

Japanese submarine I-168

I-168 was a Kaidai class submarine of the Imperial Japanese Navy during World War II. At the Battle of Midway she sank two American warships: the aircraft carrier and the destroyer . At that time she was commanded by Lieutenant Commander Yahachi Tanabe.-Early career:The submarine was completed...

, 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 equipped with a 50 cal deck weapon instead of a 65 cal.

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

United States Navy

The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...

 submarine in the war.

• Boats in classes

  Boat	Sub types	Builder	Laid down	Launched	Completed	Results	Fate
  I-68, I-168 Japanese submarine I-168 I-168 was a Kaidai class submarine of the Imperial Japanese Navy during World War II. At the Battle of Midway she sank two American warships: the aircraft carrier and the destroyer . At that time she was commanded by Lieutenant Commander Yahachi Tanabe.-Early career:The submarine was completed...	Kaidai VIa (Early production)	Kure Naval Arsenal	18 June 1931	26 June 1933	31 July 1934	Sank on 06 June 1942 Sank on 07 June 1942	Sunk by USS Scamp USS Scamp (SS-277) USS Scamp , a Gato-class submarine, was the first ship of the United States Navy to be named for the scamp, a member of the Serranidae family....  at north of Rabaul Rabaul Rabaul is a township in East New Britain province, Papua New Guinea. The town was the provincial capital and most important settlement in the province until it was destroyed in 1994 by falling ash of a volcanic eruption. During the eruption, ash was sent thousands of metres into the air and the...  27 July 1943
  I-69, I-169	Kaidai VIa (Early production)	Mitsubishi, Kōbe Shipyard	22 December 1932	15 February 1934	28 September 1935	Sank Dutch merchantman Tjinegara 21 July 1942	Sunk by air raid at Truk Chuuk Chuuk — formerly Truk, Ruk, Hogoleu, Torres, Ugulat, and Lugulus — is an island group in the south western part of the Pacific Ocean. It comprises one of the four states of the Federated States of Micronesia , along with Kosrae, Pohnpei, and Yap. Chuuk is the most populous of the FSM's...  on 04 April 1944
  I-70, I-70	Kaidai VIa (Early production)	Sasebo Naval Arsenal	25 January 1933	14 June 1934	09 November 1935		Sunk by aircraft from USS Enterprise USS Enterprise (CV-6) USS Enterprise , colloquially referred to as the "Big E," was the sixth aircraft carrier of the United States Navy and the seventh U.S. Navy ship to bear the name. Launched in 1936, she was a ship of the Yorktown class, and one of only three American carriers commissioned prior to World War II to...  in the Hawaiian Islands Hawaiian Islands The Hawaiian Islands are an archipelago of eight major islands, several atolls, numerous smaller islets, and undersea seamounts in the North Pacific Ocean, extending some 1,500 miles from the island of Hawaii in the south to northernmost Kure Atoll...  on 10 December 1941
  I-71, I-171	Kaidai VIa (Late production)	Kawasaki, Kōbe Shipyard	15 February 1933	25 August 1934	24 December 1935	Sank USS General Royal T. Frank on 19 January 1942	Sunk by USS Guest USS Guest (DD-472) USS Guest , a Fletcher-class destroyer, was a ship of the United States Navy named for Commodore John Guest ....  and USS Hudson USS Hudson (DD-475) USS Hudson , a Fletcher-class destroyer, was the second ship of the United States Navy to be named for Captain William L. Hudson ....  west of Buka Island Buka Island Buka Island is the second largest island in the Papua New Guinean province of Bougainville.- History :Buka was first occupied by humans in paleolithic times, some 30,000 years ago...  on 30 January 1944
  I-72, I-172	Kaidai VIa (Late production)	Mitsubishi, Kōbe Shipyard	16 December 1933	06 April 1935	07 January 1937	Sank USS Prusa on 19 December 1941 Sank the oiler USS Neches USS Neches (AO-5) USS Neches was laid down on 8 June 1919 by the Boston Navy Yard in Boston, Massachusetts; launched on 2 June 1920, sponsored by Miss Helen Griffin, daughter of Rear Admiral Robert Griffin; and commissioned on 25 October 1920, with Commander H. T. Meriwether, USNRF, in command.Originally classified...  on 23 January 1942	Sunk by USS Southard USS Southard (DD-207) USS Southard was a Clemson-class destroyer in the United States Navy during World War II. She was the second Navy ship named for Secretary of the Navy Samuel L...  at San Cristobal Makira The island of Makira is the largest island of Makira-Ulawa Province in the Solomon Islands. The island is located east of Guadalcanal and south of Malaita. The largest and capital city is Kirakira....  10 November 1942
  I-73	Kaidai VIa (Late production)	Kawasaki, Kōbe Shipyard	05 September 1933	20 June 1935	07 January 1937		(1). Sunk by USS Gudgeon USS Gudgeon (SS-211) USS Gudgeon , a Tambor-class submarine, was the first ship of the United States Navy to be named for the gudgeon). Her keel was laid down by the Mare Island Navy Yard. She was launched on 25 January 1941, sponsored by Mrs. William S. Pye, and commissioned on 21 April 1941 with Lieutenant Commander...  at Midway Atoll Midway Atoll Midway Atoll is a atoll in the North Pacific Ocean, near the northwestern end of the Hawaiian archipelago, about one-third of the way between Honolulu, Hawaii, and Tokyo, Japan. Unique among the Hawaiian islands, Midway observes UTC-11 , eleven hours behind Coordinated Universal Time and one hour...  28°24′N 178°35′E on 27 January 1942 (2). Sunk by USS Long USS Long (DD-209) USS Long , named for John Davis Long , Secretary of the Navy from 1897 to 1902, was a Clemson-class destroyer in the United States Navy.... , USS Jarvis USS Jarvis (DD-393) USS Jarvis , a Bagley-class destroyer, was the 2nd ship of the United States Navy to be named for James C. Jarvis, a U.S. Navy midshipman who was killed during the Quasi-War with France....  and USS Trever USS Trever (DD-339) USS Trever was a Clemson-class destroyer in the United States Navy. She was named in memory of Lt. Cmdr. George A. Trever.-History:...  at Pearl Harbor Pearl Harbor Pearl Harbor, known to Hawaiians as Puuloa, is a lagoon harbor on the island of Oahu, Hawaii, west of Honolulu. Much of the harbor and surrounding lands is a United States Navy deep-water naval base. It is also the headquarters of the U.S. Pacific Fleet...  on 29 January 1942
  I-74, I-174 Japanese submarine I-174 Japanese submarine I-174 was a Kaidai class submarine operated by the Imperial Japanese Navy between 1938 and her sinking in 1944. She completed eight war patrols during the Pacific War. She attacked the Convoy GP55 on 16 June 1943. During her ninth war patrol she was sunk near Truk on 12 April...	Kaidai VIb	Sasebo Naval Arsenal	16 October 1934	28 March 1937	15 August 1938	Sank US Army transport Portmar on 16 June 1943 and damaged USS LST-469 in an attack on Convoy GP55 Convoy GP55 Convoy GP55 was a convoy of Allied ships that travelled from Sydney to Brisbane in June 1943 during World War II. It comprised ten cargo ships, three landing ships, tank and an escort of five corvettes. The Japanese submarine I-174 attacked the convoy on 16 June, sinking the United States...  on 16 June 1943	Sunk by a United States Navy B-24 Liberator patrol aircraft near Truk Chuuk Chuuk — formerly Truk, Ruk, Hogoleu, Torres, Ugulat, and Lugulus — is an island group in the south western part of the Pacific Ocean. It comprises one of the four states of the Federated States of Micronesia , along with Kosrae, Pohnpei, and Yap. Chuuk is the most populous of the FSM's...  on 12 April 1944
  I-75, I-175	Kaidai VIb	Mitsubishi, Kōbe Shipyard	01 November 1934	16 September 1936	18 December 1938	Sank USS Manini 18 December 1941 Damaged Australian merchant ship Allara on 23 July 1942 Sank Australian merchant ship Murada on 24 July 1942 Sank French merchant vessel Cagou on 28 July 1942 Sank RMS Dranker on 03 August 1942 Sank USS Liscome Bay USS Liscome Bay (CVE-56) USS Liscome Bay , a during World War II, was the only ship of the United States Navy to be named for Liscome Bay in Dall Island in the Alexander Archipelago off Alaska's southeast coast...  on 24 November 1943	Sunk by USS Nicholas USS Nicholas (DD-449) USS Nicholas was a Fletcher-class destroyer of the United States Navy, which served through most of World War II, and for 27 years and two more wars after. She was the second Navy ship to be named for Major Samuel Nicholas....  northeast of Wotje Atoll Wotje Atoll Wotje Atoll is a coral atoll of 75 islands in the Pacific Ocean, and forms a legislative district of the Ratak Chain of the Marshall Islands. Wotje's land area of , is one the largest in the Marshall Islands, and encloses a lagoon of . The atoll is oriented east and west and is at its longest...  on 17 February 1944

Kaidai VII (I-176 class)

Project number S41. The final design in the Kaidai class, ten Kaidai VIIs were ordered in 1939 (I-176 I-185), and were completed over the course of 1942 and 1943. They were built in 1939 under the Maru 4 Programme

4th Naval Armaments Supplement Programme (Japan, 1939)

The was one of the armaments expansion plan of the Imperial Japanese Navy .-Background:In 1939, the IJN started new naval armaments expansion plan...

. The IJN called 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 endurance of 75 days.

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

• Boats in class

  Boat No.	Boat	Builder	Laid down	Launched	Completed	Results	Fate
  154	I-176 Japanese submarine I-176 The I-176, also named I-76,Although the submarine had been named I-76 when ordered in 1939, she was renamed I-176 upon her completion in 1942. was a of the Imperial Japanese Navy during World War II. The most successful submarine of her class, she severely damaged the heavy cruiser in October...	Kure Naval Arsenal	22-06-1940	07-06-1941	04-08-1942	Damaged USS Chester USS Chester (CA-27) USS Chester , a Northampton-class heavy cruiser, was the second ship of the United States Navy named after the city of Chester, Pennsylvania....  on 20-10-1942 Sank USS Corvina USS Corvina (SS-226) , a Gato-class submarine, was the only ship of the United States Navy to be named for the corvina, any of various important food fishes related to the weakfish and the croaker of the Atlantic coast....  on 17-11-1943	Sunk by USS Franks USS Franks (DD-554) USS Franks , a World War II-era Fletcher-class destroyer in the service of the United States Navy, was named after Medal of Honor recipient Acting Master's Mate William Joseph Franks....  and USS Haggard USS Haggard (DD-555) USS Haggard was a Fletcher-class destroyer of the United States Navy named for Captain Haggard of the Louisa, who fought in the Quasi-War....   northwest of Buka Island on 17-05-1944.
  155	I-177 Japanese submarine I-177 Japanese Submarine I-177 was a Japanese KD7 type that saw service during World War II in the Imperial Japanese Navy. I-177 was commissioned on 28 December 1942 and was sunk by on 3 October 1944 with the loss of her entire crew of 101 sailors...	Kawasaki, Kōbe Shipyard	10-03-1941	20-12-1941	28-12-1942	Sank RMS Limerick on 26-04-1943 Sank AHS Centaur AHS Centaur Australian Hospital Ship Centaur was a hospital ship which was attacked and sunk by a Japanese submarine off the coast of Queensland, Australia, on 14 May 1943...  on 14-05-1943	Sunk by USS Steele USS Steele (DE-8) USS Steele was an Evarts-class short-hull destroyer escort in the service of the United States Navy, named for Private John M. Steele, US Marines, killed during the Battle of the Coral Sea on 8 May 1942....  and USS Samuel S. Miles USS Samuel S. Miles (DE-183) USS Samuel S. Miles was a built for the United States Navy during World War II. She served in the Pacific Ocean and provided escort service against submarine and air attack for Navy vessels and convoys...  northwest of Palau Palau Palau , officially the Republic of Palau , is an island nation in the Pacific Ocean, east of the Philippines and south of Tokyo. In 1978, after three decades as being part of the United Nations trusteeship, Palau chose independence instead of becoming part of the Federated States of Micronesia, a...  on 03-10-1944
  156	I-178	Mitsubishi, Kōbe Shipyard	21-05-1941	24-02-1942	26-12-1942	Sank USS Lydia M. Chillds on 27-04-1943	Sunk by RAAF topedo bomber on 04-08-1943
  157	I-179	Kawasaki, Kōbe Shipyard	21-08-1941	16-07-1942	08-06-1943		Lost in an accident at Iyo Nada on 09-07-1943
  158	I-180 Japanese submarine I-180 I-180 was a Kaidai class submarine of the Imperial Japanese Navy during World War II. Laid down at the Yokosuka Naval Arsenal on 17 April 1941 and launched on 7 February 1942. Completed on 15 January 1943...	Yokosuka Naval Arsenal	17-04-1941	07-02-1942	15-01-1943	Sank Australian merchant ship Wollongbar on 29-04-1943 Sank Norwegian merchant ship Fingal SS Fingal SS Fingal was a Norwegian merchant ship of 2,137 tons which was sunk during World War II off the coast of Australia.-Brief history:The Fingal was built at Moss Værft, Norway 1923....  05-05-1943 Damaged Australian merchant vessel Ormiston on 12-05-1943 Damaged Australian merchant-man Caradale on 12-05-1943	Sunk by USS Gilmore USS Gilmore (DE-18) USS Gilmore was an Evarts-class short-hulldestroyer escort in the service of the United States Navy, named after Commander Walter William Gilmore, Supply Corps, killed on 8 May 1942 while serving as the supply officer of the in the Battle of Coral Sea.Originally allocated to the United Kingdom...  at Dutch Harbor 55°10′N 155°40′W on 27-04-1944
  159	I-181	Kure Naval Arsenal	11-11-1941	02-05-1942	25-05-1943		(1). Sunk by USN destroyer and patrol torpedo boat in New Guinea New Guinea New Guinea is the world's second largest island, after Greenland, covering a land area of 786,000 km2. Located in the southwest Pacific Ocean, it lies geographically to the east of the Malay Archipelago, with which it is sometimes included as part of a greater Indo-Australian Archipelago...  on 16-01-1944 (2). Sunk by USN carrier aircraft in the Saint George's Channel on 16-01-1944
  160	I-182	Yokosuka Naval Arsenal	10-11-1941	20-05-1942	10-05-1943		(1). Sunk by USS Wadsworth USS Wadsworth (DD-516) USS Wadsworth , a , was the second ship of the United States Navy to be named for Commodore Alexander S. Wadsworth ....  at Espiritu Santo Espiritu Santo Espiritu Santo is the largest island in the nation of Vanuatu, with an area of . It belongs to the archipelago of the New Hebrides in the Pacific region of Melanesia. It is in the Sanma Province of Vanuatu....  on 01-09-1943 (2). Sunk by USS Ellet USS Ellet (DD-398) USS Ellet was a Benham-class destroyer in the United States Navy during World War II. She was named for five members of the Ellet family of Pennsylvania who rendered service during the American Civil War: Colonel Charles Ellet, Jr.; Brigadier General Alfred W. Ellet; Colonel Charles R. Ellet;...  in the New Hebrides New Hebrides New Hebrides was the colonial name for an island group in the South Pacific that now forms the nation of Vanuatu. The New Hebrides were colonized by both the British and French in the 18th century shortly after Captain James Cook visited the islands...  on 03-09-1943
  161	I-183	Kawasaki, Kōbe Shipyard	26-12-1941	21-01-1943	03-10-1943		Sunk by USS Pogy USS Pogy (SS-266) USS Pogy , a Gato-class submarine, was the first ship of the United States Navy to be named for the pogy, or menhaden.The first Pogy was laid down 15 September 1941 by the Manitowoc Shipbuilding Co., Manitowoc, Wisc., launched 23 June 1942; sponsored by Mrs. Julius A. Furer; and commissioned 10...  south of Shikoku Shikoku is the smallest and least populous of the four main islands of Japan, located south of Honshū and east of the island of Kyūshū. Its ancient names include Iyo-no-futana-shima , Iyo-shima , and Futana-shima...  on 28-04-1944
  162	I-184	Yokosuka Naval Arsenal	01-04-1942	12-12-1942	15-10-1943		Sunk by aircraft from USS Suwannee USS Suwannee (CVE-27) USS Suwannee was laid down on 3 June 1938 at Kearny, New Jersey, by the Federal Shipbuilding and Drydock Company, under a Maritime Commission contract as Markay ; launched on 4 March 1939, sponsored by Mrs. Howard L...  southeast of Saipan Saipan Saipan is the largest island of the United States Commonwealth of the Northern Mariana Islands , a chain of 15 tropical islands belonging to the Marianas archipelago in the western Pacific Ocean with a total area of . The 2000 census population was 62,392...  on 19-06-1944
  163	I-185	Yokosuka Naval Arsenal	02-09-1942	16-09-1942	23-09-1943		Sunk by USS Newcomb USS Newcomb (DD-586) USS Newcomb was a Fletcher-class destroyer in the United States Navy during World War II. She was the only ship named for Commodore Frank H. Newcomb of the United States Revenue Cutter Service, Congressional Gold Medal recipient from the Spanish-American War.Newcomb was laid down 19 March 1943 by...  and USS Chandler USS Chandler (DD-206) USS Chandler was a Clemson-class destroyer in the United States Navy. She was the only ship named for William Eaton Chandler, who served as Secretary of the Navy from 1882 to 1886....  northwest of Saipan Saipan Saipan is the largest island of the United States Commonwealth of the Northern Mariana Islands , a chain of 15 tropical islands belonging to the Marianas archipelago in the western Pacific Ocean with a total area of . The 2000 census population was 62,392...  on 22-06-1944

Characteristics

Type		Kaidai I (I-51)	Kaidai II (I-152)	Kaidai IIIa (I-153)	Kaidai IIIb (I-156)	Kaidai IV (I-61)
Displacement	Surfaced	1390 long tons (1,412 t)	1390 long tons (1,412 t)	1635 long tons (1,661 t)	1635 long tons (1,661 t)	1575 long tons (1,600 t)
	Submerged	2430 long tons (2,469 t)	2500 long tons (2,540 t)	2300 long tons (2,337 t)	2300 long tons (2,337 t)	2300 long tons (2,337 t)
Length (overall)		91.44 metre	100.85 metre	100.58 metre	101 metre	97.7 metre
Beam		8.81 metre	7.64 metre	7.98 metre	7.9 metre	7.8 metre
Draft		4.6 metre	5.14 metre	4.83 metre	4.9 metre	4.83 metre
Depth		6.02 metre	6.71 metre	6.71 metre	6.7 metre	6.7 metre
Power plant and shaft		4 × Sulzer Sulzer (manufacturer) Sulzer Ltd. is a Swiss industrial engineering and manufacturing firm, founded by Salomon Sulzer-Bernet in 1775 and established as Sulzer Brothers Ltd. in 1834 in Winterthur, Switzerland. Today it is a publicly owned company with international subsidiaries...  Mk.2 diesels 4 shafts	2 × Sulzer Mk 3 diesels 2 shafts	2 × Sulzer Mk 3 diesels 2 shafts	2 × Sulzer Mk 3 diesels 2 shafts	2 × Rauschenbach Mk 2 diesels 2 shafts
Power	Surfaced	5,200 bhp	6,800 bhp	6,800 bhp	6,800 bhp	6,000 bhp
	Submerged	2,000 shp	1,800 shp	1,800 shp	1,800 shp	1,800 shp
Speed	Surfaced	18.4 knots (36.1 km/h)	20.1 knots (39.4 km/h)	20 knots (39.2 km/h)	20 knots (39.2 km/h)	20 knots (39.2 km/h)
	Submerged	8.4 knots (16.5 km/h)	7.7 knots (15.1 km/h)	8 knots (15.7 km/h)	8 knots (15.7 km/h)	8.5 knots (16.7 km/h)
Range	Surfaced	20000 nmi (37,040 km) at 10 knots (19.6 km/h)	10000 nmi (18,520 km) at 10 knots (19.6 km/h)	10000 nmi (18,520 km) at 10 knots (19.6 km/h)	10000 nmi (18,520 km) at 10 knots (19.6 km/h)	10000 nmi (18,520 km) at 10 knots (19.6 km/h)
	Submerged	100 nmi (185.2 km) at 4 knots (7.8 km/h)	100 nmi (185.2 km) at 4 knots (7.8 km/h)	90 nmi (166.7 km) at 3 knots (5.9 km/h)	60 nmi (111.1 km) at 3 knots (5.9 km/h)	60 nmi (111.1 km) at 3 knots (5.9 km/h)
Test depth		45.7 m (149.9 ft)	45.7 m (149.9 ft)	60 m (196.9 ft)	60 m (196.9 ft)	60 m (196.9 ft)
Fuel		508 tons	284.5 tons	241.8 tons	230 tons	230 tons
Complement		70	58	63	63	58
Armament (initial)		• 8 × 533 mm (21 in) TT Torpedo tube A torpedo tube is a device for launching torpedoes. There are two main types of torpedo tube: underwater tubes fitted to submarines and some surface ships, and deck-mounted units installed aboard surface vessels... s (6 × bow, 2 × aft) • 24 × 6th Year Type torpedoes • 1 × 120 mm (4.7 in) L/45 3rd Year Type Naval gun	• 8 × 533 mm (21 in) TTs (6 × bow, 2 × aft) • 16 × 6th Year Type torpedoes • 1 × 120 mm (4.7 in) L/45 3rd Year Type Naval gun • 1 × 76.2 mm (3 in) L/23.5 AA gun	• 8 × 533 mm (21 in) TTs (6 × bow, 2 × aft) • 16 × 6th Year Type torpedoes • 1 × 120 mm (4.7 in) L/40 11th Year Type Naval gun • 1 × 7.7 mm MG Machine gun A machine gun is a fully automatic mounted or portable firearm, usually designed to fire rounds in quick succession from an ammunition belt or large-capacity magazine, typically at a rate of several hundred rounds per minute....	same as Kaidai IIIa	• 6 × 533 mm (21 in) TTs (4 × bow, 2 × aft) • 14 × Type 89 torpedoes • 1 × 120 mm (4.7 in) L/40 11th Year Type Naval gun • 1 × 7.7 mm MG

Type		Kaidai V (I-165)	Kaidai VIa (Early production, I-168)	Kaidai VIa (Late production, I-171)	Kaidai VIb (I-174)
Displacement	Surfaced	1575 long tons (1,600 t)	1400 long tons (1,422 t)	same as Early Production	1420 long tons (1,443 t)
	Submerged	2330 long tons (2,367 t)	2440 long tons (2,479 t)		2564 long tons (2,605 t)
Length (overall)		97.7 metre	104.7 metre		105 metre
Beam		8.2 metre	8.2 metre		8.2 metre
Draft		4.7 metre	4.58 metre		4.6 metre
Depth		7.05 metre	7 metre		7 metre
Power plant and shaft		2 × Sulzer Mk.3 diesels 2 shafts	2 × Kampon Imperial Japanese Navy Technical Department The was the externally operating division of the Ministry of the Navy of Japan responsible for the administration of naval vessel construction. From 1923 onward, it took on the role of a research institution for the research and development of naval technologies and engineering... Mk.1A Model 8 diesels, 2 shafts		2 × Kampon Mk 1A Model 8 diesels, 2 shafts
Power	Surfaced	6,000 bhp	9,000 bhp		9,000 bhp
	Submerged	1,800 shp	1,800 shp		1,800 shp
Speed	Surfaced	20.5 knots (40.2 km/h)	23 knots (45.1 km/h)		23 knots (45.1 km/h)
	Submerged	8.2 knots (16.1 km/h)	8.2 knots (16.1 km/h)		8.2 knots (16.1 km/h)
Range	Surfaced	10000 nmi (18,520 km) at 10 knots (19.6 km/h)	14000 nmi (25,928 km) at 10 knots (19.6 km/h)		10000 nmi (18,520 km) at 16 knots (31.4 km/h)
	Submerged	60 nmi (111.1 km) at 3 knots (5.9 km/h)	65 nmi (120.4 km) at 3 knots (5.9 km/h)		90 nmi (166.7 km) at 3 knots (5.9 km/h)
Test depth		75 m (246.1 ft)	70 m (229.7 ft)		85 m (278.9 ft)
Fuel		230 tons	341 tons		442 tons
Complement		62	68		68
Armament (initial)		• 6 × 533 mm (21 in) TTs (4 × bow, 2 × aft) • 14 × Type 89 torpedoes • 1 × 100 mm (3.9 in) L/50 Type 88 AA gun • 1 × 12.7 mm AA gun • 1 × 7.7 mm MG	• 6 × 533 mm (21 in) TTs (4 × bow, 2 × aft) • 14 × Type 89 torpedoes • 1 × 100 mm (3.9 in) L/50 Type 88 AA gun • 1 × 13.2 mm AA gun • 1 × 7.7 mm MG	• 6 × 533 mm (21 in) TTs (4 × bow, 2 × aft) • 14 × Type 89 torpedoes • 1 × 120 mm (4.7 in) L/40 11th Year Type Naval gun • 1 × 13.2 mm AA gun • 1 × 7.7 mm MG	• 6 × 533 mm (21 in) TTs (4 × bow, 2 × aft) • 14 × Type 89 torpedoes • 1 × 120 mm (4.7 in) L/40 11th Year Type Naval gun • 1 × 13.2 mm AA gun