Warships of Japan: Imperial Japanese Navy Submarines of the Second World War

Japanese submarines of the Second World War

Former IJN units at Kure harbour, Honshu, Japan, on 12 October 1945

(Official USN Photo, located at the US National Archives,CVE-29 Photo, 80-G-353701)

Japanese Submarines by Class

I-1-class.

I-1.

I-2.

I-5.

I-6.

I-7.

I-8.

Submarine I-1, I-2, I-3, I-4, I-5, I-6, I-7, I-8

‍1,970 tonnes. The official designation of the submarine was Junsen-type submarine.

I-9-class

I-10.

(Official USN Photo, located at the US National Archives, 80-G-701062)

I-14, 25 September 1945.

(U.S. Naval History and Heritage Command Photo NH 97841)

The U.S. Navy submarine tender USS Euryale (AS-22) at Sasebo, Japan, in November 1945. She has three large Japanese submarines alongside. They are (from inboard to outboard): I-401, I-14 and I-400.

(USN Photo)

I-401 between the U.S. Navy submarine tender USS Proteus (left) and the Japanese submarine I-14 (right) after the end of hostilities, 29 August 1945.

I-14, 25 September 1945.

(Official USN Photo, located at the US National Archives, 80-G-701060)

Ex-IJN submarines I-14 (centre) and I-400 at Sagami Bay, 25 September 1945.

(Official USN Photo, located at the US National Archives, 80-G-701061)

Ex-IJN submarines I-14 (centre) and I-400 at Sagami Bay, 25 September 1945.

With postwar relations with the Soviet Union deteriorating rapidly and concerns growing in the United States that under postwar agreements the Soviets would demand access to the captured Japanese submarines that would provide the Soviet Navy with valuable information about advanced Japanese submarine designs, the U.S. Navy issued orders on 26 March 1946 to sink all captured Japanese submarines. Accordingly, the U.S. Navy sank I-401 as a target in tests of the Mark 10 Mod 3 exploder off Pearl Harbor on 31 May 1946. She sank by the stern at 10:59 at 21°1′N 158°07′W after the submarine USS Cabezon (SS-334) hit her with two Mark 18 torpedoes.

Submarine I-9, I-10, I-11, I-12, I-13, I-14

2,434 tonnes. The official designation of the submarine was Type A (Ko) submarine.

I-15-class

I-15.

I-26.

I-45.

I-58.

Submarine I-15, I-17, I-19, I-21, I-23, I-25, I-26, I-27, I-29, I-30, I-31, I-32, I-33, I-34, I-35, I-36, I-37, I-38, I-39, I-40, I-41, I-42, I-43, I-44, I-45, I-54, I-58

‍2,184 tonnes. The official designation of the submarine was Type B (Otsu) submarine.

I-16-class

I-18.

I-48.

I-55.

Submarine I-16, I-18, I-22, I-24, I-46, I-47, I-48, I-52, I-53, I-55

2,184 tonnes, The official designation of the submarine was Type C (Hei) submarine.

I-361-class

I-361.

I-363.

Submarine I-361, I-362, I-363, I-364, I-365, I-366, I-367, I-368, I-369, I-370, I-371, I-372, I-373

1,440 tonnes. The official designation of the submarine was Type D (Tei) submarine.

I-51-class

I-51.

I-152.

I-155.

I-156.

(National Archives 80-G-260245)

Operation "Road's End", Japanese submarines I-156 and Ha-203 are prepared for scuttling, off Sasebo, Japan, 1 April 1946. U.S. Navy ships and other Japanese ships are in the background.

I-61. I-61 was lost in a collision in October 1941, refloated, and scrapped.

I-164.

I-165.

I-168.

I-173.

I-175.

I-176.

Submarines I-51, I-152, I-153, I-154, I-155, I-156, I-157, 1-158, I-159, I-60, I-61, I-162, I-63, I-164, I-165, I-66, I-67, I-168, I-169, I-70, I-171, I-173, I-174, I-175, I-176, I-177, I-178, I-179, I-180, I-181, I-182, I-183, I-184, I-185‍

1,575 tonnes. The official designation of the submarine was Kaidai-type submarine.

I-121-class

I-121.

Submarine I-121, I-122, I-123, I-124

‍1,142 tonnes. The official designation of the submarine was Kiraisen-type submarine.

I-351-class

I-351.

Submarine I-351

3,512 tonnes. Planned 6. Completed 1. The official designation of the submarine was Senho-type submarine.

I-201-class

I-201.

I-201.

Submarine I-201 1, I-202 1, I-203

Ha-201, Ha-202, 1945.

(Naval History and Heritage Command Photo, 80-G-351898)

Japanese submarines Ha-203 2 (left), Ha-204 2 (left center), Japanese submarine I-203 2 (large submarine at center), and Japanese submarine Ha-106 2 (conning tower visible to right of I-203) at Kure, Japan.

‍1,503 tonnes. The official designation of the submarine was Sentaka-type submarine.

Japanese submarine Ha-230, 1945.

I-501-class Submarine I-501

‍1,616 tonnes. This was a German Kriegsmarine submarine under the name U-181, until given to Japan in May 1945.

I-502-class Submarine I-502

‍1,610 tonnes. This was a German Kriegsmarine submarine under the name U-862, until given to Japan May 1945.

I-503-class Submarine I-503

I-503.

1,610 tonnes. This was an Italian Regia Marina submarine under the name Comandante Cappelini then captured by IJN after Italy's capitulation then given to the German Kriegsmarine in September 1943 under the name UIT-24. After that, it was captured again by IJN in May 1945. after Germany's surrender.

I-504-class Submarine I-504

‍‍1,763 tonnes. This was an Italian Regia Marina submarine under the name Luigi Torelli. It was temporarily interned to IJN after Italy's capitulation then given to the German Kriegsmarine in September 1943 under the name UIT-25. After that it was captured again by IJN in May 1945 after Germany's surrender.

I-505-class Submarine I-505

‍1,763 tonnes. This was a German Kriegsmarine submarine under the name U-219, until it was given to Japan in May 1945.

I-506-class Submarine I-506

‍1,610 tonnes. This was a German Kriegsmarine submarine under the name U-195, until given to Japan May 1945.

Ro-11-class

Ro-11.

Ro-16.

Ro-24.

Ro-31.

Ro-33.

Ro-45.

Ro-50.

Submarine Ro-11, Ro-12, Ro-13, Ro-14, Ro-15, Ro-16, Ro-17, Ro-18, Ro-19, Ro-20, Ro-21, Ro-22, R0-23, Ro-24, Ro-25, Ro-26, Ro-27, Ro-28, Ro-29, Ro-30, Ro-31, Ro-32, 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, Rp-55, Ro-56.

720 tonnes. The official designation of the submarine was Type Kaichū submarine.

Ro-51-class

Ro-51.

Ro-56.

Ro-58.

Ro-63.

Ro-64.

Submarine Ro-51, Ro-52, Ro-53, Ro-54, Ro-55, Ro-56, Ro-57, Ro-58, Ro-59, Ro-60, Ro-61, Ro-62, Ro-63, Ro-64, Ro-65, Ro-66, Ro-67, Ro-68.

‍893 tonnes. The official designation of the submarine was Type L submarine.

Ro-100-class

Ro-101.

Submarine Ro-100, Ro-101, Ro-102, Ro-103, Ro-104, Ro-105, Ro-106, Ro-107, Ro-109, Ro-110, Ro-111, Ro-112, Ro-113, Ro-114, Ro-115, Ro-116, Ro-117.

525 tonnes.

Ha-201-class

Two Ha-201-class submarines on the starboard side of the Japanese aircraft carrier Junyō at Sasebo, Japan, 26 September 1945.

Ha-204.

Ha-204, Ha-203, Ha-109 in 1945.

Submarine Ha-201, Ha-202, Ha-203, Ha-204, Ha-205, Ha-207, Ha-208, Ha-209, Ha-210, Ha-216.

‍320 tonnes. Never saw combat. The official designation of the submarine was Sentaka-Shō type submarine.

Ro-500-class.

Submarine Ro-500.

‍1,120 tonnes. This was a German Kriegsmarine submarine under the name U-511, until it was given to Japan on 16 September 1943.

Ro-501-class

Submarine Ro-501

‍1,144 tonnes.  This was a  German Kriegsmarine submarine under the name U-1224, until it was given to Japan on 15 February 1944.

Submarine aircraft carrier

I-400-class

(USN Photo)

I-401 (伊号第四百一潜水艦, I-gō-dai yon-hyaku-ichi-sensuikan) was an Imperial Japanese Navy Sentoku-type (or I-400-class) submarine commissioned in 1945 for service in the Second World War. Capable of carrying three two-seat Aichi M6A1 "Seiran" (Mountain Haze) float-equipped torpedo bombers, the Sentoku-class submarines were built to launch a surprise air strike against the Panama Canal. Until 1965, the Sentaku-type submarines — I-401 and her sister ships I-400 and I-402 — were the largest submarines ever commissioned. (Wikipedia)

(HawkeyeUK Photo)

Aichi M6A1 Seiran, c/n 1600228, on display in the NASM Udvar Hazy Center. The M6A was designed to be operated entirely from an I-400 class submarine and could be used either as a dive bomber or a torpedo bomber. The prototype first flew in November 1943 and the first production aircraft was completed in October 1944. The name ‘Seiran’ translates as ‘Clear Sky Storm’, but the type was never encountered in combat and did not get allocated an Allied reporting name. The first operational mission was to have been an attack on the Gatun Locks of the Panama Canal, to cut off the American supply route. Two submarines, the I-400 and I-401, sailed on 23rd July 1945 carrying six Serians between them, with the aircraft reportedly painted in US markings. The Japanese surrendered before the attack took place and the aircraft were destroyed to prevent capture. This is the only surviving example of the type and is the last of the 28 aircraft built. She was surrendered to American occupation forces in Yokosuka by Lt. Kazuo Akatsuka of the Imperial Japanese Navy, who flew the aircraft from Fukuyama. It was shipped to the United States and became one of a large number of aircraft stored for museum use, officially being handed over to the Smithsonian Institute in 1960. Restoration began in June 1989 but having previously spent many years outside she was in a poor state and the project was not completed until February 2000. She is seen on display in the Steven F. Udvar Hazy Center as part of the National Air and Space Museum. Washington Dulles International Airport, Chantilly, Virginia

I-401, 13 September 1945

(Official USN Photo, located at the US National Archives, 80-G-345189)

I-401, 13 September 1945

(Official USN Photo, located at the US National Archives, 80-G-345187)

Submarine aircraft carrier I-400, I-401, I-402

6,560 tonnes. The official designation of this submarine was Sentoku type Submarine.

Transport Submarine

Ha-101-class

(National Archives Photo, 80-G-260243)

Operation "Road's End" Japanese HA-101 class submarine en route to be scuttled, off Sasebo, Japan, 1 April 1946.

Japanese submarines Ha-101 Ha-102, and Ha-104, 8 Dec 1945.

Ha-109 and Ha-111.

Ha-105, Ha-106 and Ha-109, 1945.

Transport submarine Ha-101, Ha-102, Ha-103, Ha-104, Ha-105, Ha-106, Ha-107, Ha-108, Ha-109, Ha-111

‍370 tonnes. The official designation of this submarine was Sen'yu type submarine.

Yu-class

Yu-1.

Yu-1001.

Transport submarine Yu-1, Yu-2, Yu-3, Yu-4, Yu-5, Yu-6, Yu-7, Yu-8, Yu-9, Yu-10, Yu-11, Yu-12, Yu-13, Yu-14, Yu-15, Yu-16, Yu-17, Yu-18, Yu-19, Yu-20, Yu-21, Yu-22, Yu-23, Yu-24, Yu-1001, Yu-1002, Yu-1003, Yu-1005, Yu-1006, Yu-1007, Yu-1008, Yu-1009, Yu-1010, Yu-2001, Yu-2002, Yu-3001, Yu-3002, Yu-3003.

‍274 tonnes.

Submarine Tender

Jingei-class

Submarine tender Jingei Chogei.

‍6,240 tonnes.

Taigei-class

Submarine tender Taigei.

‍16,700 tonnes. Later converted into a light aircraft carrier.

Midget submarines

US Navy Historical Center caption : "Japanese Type D ("Koryu") Midget Submarines In a drydock at Kure Naval Base, Japan, 19 October 1945. There are at least four different types of midget submarines in this group of about eighty-four boats, though the great majority are of the standard "Koryu" type. The two boats at right in the second row appear to have an enlarged conning tower and shortened hull superstructure. The two boats at left in that row are of the earlier Type A or Type C design, as are a few others further back in the group."

This class includes the smallest of the Japanese submarines, from midget submarines to manned torpedoes often used for suicide attacks.

Type A Kō-hyōteki-class submarine

Kō-hyōteki-class submarine grounded after the Attack on Pearl Harbor, December 1941.

The Kō-hyōteki class of Japanese midget submarines had hull numbers but no names. Forsimplicity, 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 Ko-hyoteki 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.

HIJMS Landing Ship No. 5, carrying Kō-hyōteki No. 69, at Nasakejima Island, 17 August 1944.

(Library and Archives Canada Photo, MIKAN No. 3599747)

Canadian and American soldiers examine abandoned Imperial Japanese Navy Ko-hyoteki class midget submarines found at Kiska in the Aleutian Islands, Alaska, 1 Sep 1943.

(USN Photo)

A heavily damaged midget submarine base constructed by occupying Japanese forces on Kiska Island, photo taken sometime in 1943, after Allied forces retook the island.

(Author Photo)

Imperial Japanese Navy Ko-hyoteki class midget submarine used at Pearl Harbor on 7 Dec 1941.  National Museum of the Pacific War, Fredericksburg, Texas.

Kairyū-class submarine

Japanese "Kairyu" type midget submarines at the Yokosuka Naval Base, Japan, September 1945. Boats bearing numbers 4016 (at right) and 4018 (3rd from right) are training versions, with a second periscope mounted behind the main periscope's fairing, 1 Sep 1945.

Class of 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.

(At by At Photo)

Kairyu in the Yamato Museum, Japan.

(Yasuhiro Arakawa Photo)

Kairyu in the Yamato Museum, Japan.

Kaiten

Kaiten manned torpedoes, stacked atop a departing submarine.

The Kaiten was a torpedo modified as a suicide weapon, and used by the Imperial Japanese Navy inthe final stages of the Second World War. Kaiten means "return to the sky"; however, it is commonly translated as "turn toward heaven".

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.

Six models were designed, the types 1, 2, 4, 5 and 6 were based on the Long Lance type 93 torpedo (24 inch oxygen/kerosene), and the Type 10, based on the Type 92 torpedo (21 inch electric). Types 2, 4, 5, 6and 10 were only manufactured as prototypes and never used in combat.

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