The was a fleet of the
Imperial Japanese NavyThe Imperial Japanese Navy , literally Navy of the Empire of Greater Japan 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...
during
World War IIWorld War II, or the Second World War , was a global military conflict which involved a majority of the world's nations, including all great powers, organized into two opposing military alliances: the Allies and the Axis...
, primarily responsible for command of
submarineA submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has only limited underwater capability...
operations.
The IJN 6th Fleet was formed on 15 November 1940, and was assigned general control of all Japanese submarine operations. Its initial mission was reconnaissance off the west coast of the
United StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
, east coast of
AustraliaAustralia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the continental mainland , the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans...
, and the
sea laneA sea lane is regularly used route for ocean-going and Great Lakes vessels. In the time of sailing ships they were not only determined by the distribution of land masses but also the prevailing winds, whose discovery was crucial for the success of long voyages. Sea lanes are very important for...
s of the
Indian OceanThe Indian Ocean is the third largest of the world's oceanic divisions, covering about 20% of the water on the Earth's surface. It is bounded on the north by South Asia ; on the west by Africa; on the east by Indochina, the Sunda Islands, and Australia; and on the south by the Southern Ocean...
.
Prior to
World War IIWorld War II, or the Second World War , was a global military conflict which involved a majority of the world's nations, including all great powers, organized into two opposing military alliances: the Allies and the Axis...
, Japan had a very diverse and technically advanced submarine fleet, including the only submarines of over 5,000 tons submerged
displacementA ship's displacement is its mass at any given time, generally expressed in metric tons or long tons. The term is often used to mean the ship's mass when it is loaded to its maximum capacity. A number of synonymous terms exist for this maximum mass, such as loaded displacement, full load...
, or submarines over 400 feet in length until the advent of
nuclear powerNuclear power is power produced from controlled nuclear reactions. Commercial plants in use to date use nuclear fission reactions....
.
The was a fleet of the
Imperial Japanese NavyThe Imperial Japanese Navy , literally Navy of the Empire of Greater Japan 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...
during
World War IIWorld War II, or the Second World War , was a global military conflict which involved a majority of the world's nations, including all great powers, organized into two opposing military alliances: the Allies and the Axis...
, primarily responsible for command of
submarineA submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has only limited underwater capability...
operations.
History
The IJN 6th Fleet was formed on 15 November 1940, and was assigned general control of all Japanese submarine operations. Its initial mission was reconnaissance off the west coast of the
United StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
, east coast of
AustraliaAustralia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the continental mainland , the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans...
, and the
sea laneA sea lane is regularly used route for ocean-going and Great Lakes vessels. In the time of sailing ships they were not only determined by the distribution of land masses but also the prevailing winds, whose discovery was crucial for the success of long voyages. Sea lanes are very important for...
s of the
Indian OceanThe Indian Ocean is the third largest of the world's oceanic divisions, covering about 20% of the water on the Earth's surface. It is bounded on the north by South Asia ; on the west by Africa; on the east by Indochina, the Sunda Islands, and Australia; and on the south by the Southern Ocean...
.
Background
Prior to
World War IIWorld War II, or the Second World War , was a global military conflict which involved a majority of the world's nations, including all great powers, organized into two opposing military alliances: the Allies and the Axis...
, Japan had a very diverse and technically advanced submarine fleet, including the only submarines of over 5,000 tons submerged
displacementA ship's displacement is its mass at any given time, generally expressed in metric tons or long tons. The term is often used to mean the ship's mass when it is loaded to its maximum capacity. A number of synonymous terms exist for this maximum mass, such as loaded displacement, full load...
, or submarines over 400 feet in length until the advent of
nuclear powerNuclear power is power produced from controlled nuclear reactions. Commercial plants in use to date use nuclear fission reactions....
. Japan was also unique in that it built 41 submarines that could carry aircraft: something no other nation had yet produced. Japan also had submarines with the longest ranges and highest speeds of any nation. With the development of the
Type 95The Type 95 torpedo was a torpedo of the Imperial Japanese Navy. Based on the formidable Type 93 torpedo , the Type 95 had a smaller warhead, less range and a smaller diameter, and intended to be fired from a standard 533mm torpedo tube of a submerged submarine...
submarine-launched variant of the Long Lance oxygen-propelled torpedo, Japan not only had the world's most advanced torpedo, but one with the largest warhead.
[Polar, Submarines of the Imperial Japanese Navy]
However, despite numerous technical advantages, Japanese submarines achieved remarkably little during World War II. This was primarily due to the antiquated strategy of the
Imperial Japanese Navy General StaffThe was the highest organ within the Imperial Japanese Navy. In charge of planning and operations, it was headed by an Admiral headquartered in Tokyo.-History:...
, which viewed submarines as little more than scouts, whose main role was to locate and shadow enemy naval task forces in preparation for a decisive surface conflict.
Early stages of the Pacific War
At the start of the
Pacific WarThe Pacific War was the part of World War II—and preceding conflicts—that took place in the Pacific Ocean, its islands, and in East Asia. The war began as a conflict with the Empire of Japan and the Republic of China on July 7, 1937, but by December 1941, became part of the greater World War II,...
,
Midget submarineA midget submarine is any submarine under 150 tons, typically operated by a crew of one or two but sometimes up to 6 or 8, with little or no on-board living accommodation...
s were used in preparatory reconnaissance of the
US NavyThe United States Navy is the sea branch of the U.S. Armed Forces. It is one of the seven uniformed services of the United States. As of 31 December 2008, the U.S. Navy had about 331,682 personnel on active duty and 124,000 in the Navy Reserve. It operates 283 ships in active service and more than...
anchorage at
Pearl HarborPearl Harbor is a 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...
,
HawaiiHawaii is the newest of the 50 U.S. states, and is the only state made up entirely of islands. It is located on an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of Australia. The state was admitted to the Union on August...
, and in the initial stages of the
attack on Pearl HarborThe attack on Pearl Harbor was a surprise military strike conducted by the Japanese navy against the United States' naval base at Pearl Harbor, Hawaii, on the morning of Sunday, December 7, 1941 , later resulting in the United...
.
With the outbreak of general war, the mission of the IJN 6th Fleet expanded to include shipping interdiction and
mine layingA naval mine is a self-contained explosive device placed in water to destroy ships or submarines. Unlike depth charges, mines are deposited and left to wait until they are triggered by the approach of or contact with an enemy ship...
. A few specialized missions, such as the
Attack on Sydney HarbourIn late May and early June 1942, during World War II, submarines belonging to the Imperial Japanese Navy made a series of attacks on the cities of Sydney and Newcastle in New South Wales, Australia...
with the use of midget submarines were also undertaken. The IJN 6th fleet cooperated briefly with the
German NavyThe German Navy The German Navy The German Navy (Deutsche Marine is the navy of Germany and part of the Bundeswehr (German Armed Forces).The German Navy traces its roots back to the Imperial Fleet (Reichsflotte) of the revolutionary era of 1848–1852 and more directly to the Prussian Navy, which...
in the
Indian OceanThe Indian Ocean is the third largest of the world's oceanic divisions, covering about 20% of the water on the Earth's surface. It is bounded on the north by South Asia ; on the west by Africa; on the east by Indochina, the Sunda Islands, and Australia; and on the south by the Southern Ocean...
in operations to interdict
BritishThe United Kingdom of Great Britain and Northern Ireland is a sovereign state located off the northwestern coast of continental Europe. It is an island country, spanning an archipelago including Great Britain, the northeastern part of Ireland, and many small islands...
commerce from its base in
PenangPenang is a state in Malaysia, located on the northwest coast of Peninsular Malaysia by the Strait of Malacca. Penang is the second smallest state in Malaysia after Perlis, and the eighth most populous...
, but these missions were a minority. The Navy General Staff placed more emphasis on ambush operations of Allied
capital shipThe capital ships of a navy are its most important warships; the ones with the heaviest firepower and armor. A capital ship is generally a leading or a primary ship in a fleet....
s. In 1942, Japanese submarines were credited with sinking two
aircraft carrierAn aircraft carrier is a warship designed with a primary mission of deploying and recovering aircraft, acting as a seagoing airbase. Aircraft carriers thus allow a naval force to project air power great distances without having to depend on local bases for staging aircraft operations...
s, one
cruiserA cruiser is a large type of warship, which had its prime period from the late 19th century to the end of the Cold War. The first cruisers were intended for individual raiding and protection missions on the seas...
and several
destroyerIn naval terminology, a destroyer is a fast and maneuverable yet long-endurance warship intended to escort larger vessels in a fleet, convoy or battle group and defend them against smaller, short-range but powerful attackers .Before World War II, destroyers were light vessels without the endurance...
s, as well as damaging one aircraft carrier and two
battleshipA battleship is a large, heavily armored warship with a main battery consisting of the largest caliber of guns. Battleships were larger, better armed and armored than cruisers or destroyers. There are currently no battleships in service....
s.
However, the success of 1942 could not be repeated in 1943, due to increased
anti-submarineAnti-submarine warfare is a branch of naval warfare that uses surface warships, aircraft, or other submarines to find, track and deter, damage or destroy enemy submarines....
capabilities by the US Navy and to the vast scale of the Pacific conflict, which made it difficult for a submarine to be in “right place at the right time” to make a successful attack.
Latter stages of the Pacific War
After 1942, the Navy General Staff also gave very little support to continued commerce interdiction or ambush operations. Instead, submarines came to be increasingly used (especially after massive Japanese surface vessel losses in the
Solomon Islands campaignThe Solomon Islands campaign was a major campaign of the Pacific War of World War II. The campaign began with Japanese landings and occupation of several areas in the British Solomon Islands and Bougainville, in the Territory of New Guinea, during the first six months of 1942...
for transport of critical supplies and reinforcements to the starving garrisons on isolated islands. The Japanese Navy expended hundreds of sorties on such missions, which might have otherwise been used offensively against the Allied war effort.
In the meantime, continuous developments in anti-submarine warfare by the US Navy resulted in ever-increasing losses for Japan's submarine fleet. Japan started the war with 63 ocean-going submarines (not including midgets), and completed 111 during the war, for a total of 174. Of this total, 128 vessels were lost during the conflict. Most of the survivors were either training vessels, or were else recently completed by the end of the war and never saw combat. Of the 30 submarines that supported the Pearl Harbor attack, none survived the war.
KwajaleinKwajalein Atoll , is part of the Republic of the Marshall Islands . The southernmost and largest island in the atoll is named Kwajalein Island, nicknamed Kwaj by English-speaking residents of the U.S...
in the
Marshall IslandsThe Marshall Islands , officially the Republic of the Marshall Islands , is a Micronesian nation of atolls and islands in the middle of the Pacific Ocean, just west of the International Date Line and just north of the Equator. This nation of roughly 62,000 people is located north of Nauru and...
was the main base for Japanese submarine operations in the Pacific until it fell to the Americans in February 1944. IJN 6th fleet headquarters was relocated to
SaipanSaipan is the largest island and capital 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...
in the
Mariana IslandsThe 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...
, which the fell to the Americans in July 1944 with the death of IJN 6th fleet commander in chief Admiral
Takeo Takagiwas an admiral in the Imperial Japanese Navy during World War II.-Biography:Takagi was a native of Iwaki city, Fukushima prefecture. He was a graduate of the 39th class of the Imperial Japanese Naval Academy, ranking 17th of 148 cadets in 1911...
and most of his staff. The remnants of the IJN 6th fleet were based at
UlithiUlithi is an atoll in the Caroline Islands of the western Pacific Ocean, about 191 km east of Yap. It consists of 40 islets totalling , surrounding a lagoon about long and wide—at the fourth largest in the world. It is administered by the state of Yap in the Federated States of Micronesia....
Atoll in the
Caroline IslandsThe Caroline Islands form a large archipelago of widely scattered islands in the western Pacific Ocean, northeast of New Guinea. Politically they are divided between the Federated States of Micronesia in the eastern part of the group, and Palau at the extreme western end...
until the end of the war.
Japan's submarine forces were unable to provide much support during the Battle of the Philippines due to increased vigilance by the American fleet. In the final stages of the war, surviving submarines were largely used as carriers for
kaitenThe Kaiten The Kaiten The Kaiten ' onMouseout='HidePop("98068")' href="http://www.absoluteastronomy.com/topics/Japanese_submarine_I-401">Japanese submarine I-401
The Sen Toku-class I-401 was once the largest submarine in the world. It was commanded by Lieutenant Commander Nambu. Capable of carrying three two-seat Aichi M6A1 "Seiran" float torpedo bombers, the Sen Tokus were built to launch a surprise air strike against the Panama Canal.-Service...
returned to
Yokosukais a city located in Kanagawa, Japan.It is located at the mouth of Tokyo Bay in the Miura Peninsula, and the city stretches across the peninsula to Sagami Bay. Its neighbors are Yokohama, Miura, Hayama, and Zushi.-Heian period:...
from Ulithi.
15 November 1940
- Submarine Squadron 1 : Training cruiser Katori
was the lead ship of the Katori class of three light cruisers which served with the Imperial Japanese Navy during World War II. It is named after the noted Shinto shrine Katori Shrine in Chiba prefecture, Japan.-Background:...
(Flagship), Submarine tender TaigeiThe was a Japanese Light aircraft carrier. Sole ship of her class, she was converted from a submarine tender. During WW2 she operated mainly as aircraft transport but did participate in the First Battle of the Philippine Sea.-Conversion and commission:...
, Submarine I-20
- Submarine Flotilla 1 : Submarine I-15, I-16, I-17
- Submarine Squadron 2 : Light cruiser Isuzu
was one of six s in the Imperial Japanese Navy. It was named after the Isuzu River, near Ise Shrine in the Chūbu region of Japan.-Background:Isuzu was the second of the six vessels completed in the Nagara-class of light cruisers, and like other vessels of her class, she was intended for use as...
- Submarine Flotilla 11 : Submarine I-74, I-75
- Submarine Flotilla 12 : Submarine I-68, I-69, I-70
- Submarine Flotilla 20 : Submarine I-71, I-72, I-73
- Submarine Squadron 3 : Submarine tender Chōgei, Submarine I-7
- Submarine Flotilla 7 : Submarine I-1, I-2, I-3
- Submarine Flotilla 8 : Submarine I-4, I-5, I-6
1 December 1941
- Training cruiser Katori
was the lead ship of the Katori class of three light cruisers which served with the Imperial Japanese Navy during World War II. It is named after the noted Shinto shrine Katori Shrine in Chiba prefecture, Japan.-Background:...
(Flagship), Fleet oiler Ondo
- Submarine Squadron 1 : Auxiliary submarine tender Yasukuni-maru, Submarine I-9
- Submarine Flotilla 1 : Submarine I-15, I-16, I-17
- Submarine Flotilla 2 : Submarine I-18, I-19, I-20
- Submarine Flotilla 3 : Submarine I-21, I-22, I-23
- Submarine Flotilla 4 : Submarine I-24, I-25, I-26
- Submarine Squadron 2 : Auxiliary submarine tender Santos-maru, Submarine I-7, I-10
- Submarine Flotilla 7 : Submarine I-1, I-2, I-3
- Submarine Flotilla 8 : Submarine I-4, I-5, I-6
- Submarine Squadron 3 : Submarine tender Taigei, Submarine I-8
- Submarine Flotilla 11 : Submarine I-74, I-75
- Submarine Flotilla 12 : Submarine I-68, I-69, I-70
- Submarine Flotilla 20 : Submarine I-71, I-72, I-73
15 June 1944
(The 6th fleet does not have a flagship, because the headquarters moved to the land.)
- Submarine I-10
- Submarine Squadron 7
- Submarine Flotilla 51 : Submarine Ro-104, Ro-105, Ro-106, Ro-107, Ro-108, Ro-109, Ro-111, Ro-112, Ro-113, Ro-114, Ro-115, Ro-116, Ro-117
- Submarine Squadron 8 : Submarine I-8, I-26, I-27, I-29, I-37, I-52, I-165, I-166, Ro-501
- Submarine Squadron 11 : Submarine tender Chōgei, Submarine I-33, I-46, I-54, I-55, I-361, I-362, Ro-46, Ro-48
- Submarine Flotilla 7 : Submarine I-5, I-6
- Submarine Flotilla 12 : Submarine I-169, I-174, I-175, I-176
- Submarine Flotilla 15 : Submarine I-16, I-32, I-36, I-38, I-41, I-44, I-45, I-53
- Submarine Flotilla 22 : Submarine I-177, I-180, I-183, I-184, I-185
- Submarine Flotilla 34 : Submarine Ro-36, Ro-41, Ro-42, Ro-43, Ro-44, Ro-45, Ro-47
1 June 1945
- Patrol Squadron 22 : Auxiliary boom defence vessel Kiku-maru
- Hunter-Killer Squadron 31 : Destroyer Hanazuki
Hanazuki was an Akizuki-class destroyer of the Imperial Japanese Navy. Her name means " March". In June 1947, Hanazuki was turned over to United States as "DD-934", and was later sunk as target off Gotō Islands, Japan on 3 February 1948.-Commanding Officers:* Chief Equipping Officer - Cmdr. Hideo...
- Destroyer Division 17 : Destroyer Yukikaze
was a in service with the Imperial Japanese Navy during World War II. She was the only member of her class to survive the war. The attrition rate of Japanese destroyers was extremely high due to heavy, prolonged combat and the need to use them to transport supplies to scattered Japanese island...
- Destroyer Division 41 : Destroyer Suzutsuki
Suzutsuki was a Akizuki-class destroyer of the Imperial Japanese Navy. Her name means "Clear Moon ".On 6–7 April 1945, Suzutsuki escorted from the Inland Sea on her attack mission against the Allied forces fighting on Okinawa...
, FuyuzukiFuyuzuki was a Akizuki-class destroyer of the Imperial Japanese Navy. Her name means "Winter Moon".On 12 October 1944, while escorting the light cruiser from Yokosuka to the Inland Sea, she was hit on the bow by a torpedo fired from...
- Destroyer Division 43 : Destroyer Take
The were a class of destroyer built for the Imperial Japanese Navy , who referred to them as .*The and the were called .*The was called .*The was called .-Design basis:...
, KiriThe were a class of destroyer built for the Imperial Japanese Navy , who referred to them as .*The and the were called .*The was called .*The was called .-Design basis:...
, MakiThe were a class of destroyer built for the Imperial Japanese Navy , who referred to them as .*The and the were called .*The was called .*The was called .-Design basis:...
, SiiThe were a class of destroyer built for the Imperial Japanese Navy , who referred to them as .*The and the were called .*The was called .*The was called .-Design basis:...
- Destroyer Division 52 : Destroyer Sugi
The were a class of destroyer built for the Imperial Japanese Navy , who referred to them as .*The and the were called .*The was called .*The was called .-Design basis:...
, KashiThe were a class of destroyer built for the Imperial Japanese Navy , who referred to them as .*The and the were called .*The was called .*The was called .-Design basis:...
, KabaThe were a class of destroyer built for the Imperial Japanese Navy , who referred to them as .*The and the were called .*The was called .*The was called .-Design basis:...
, Escort ship CD-31, CD-43
- Submarine Squadron 11 : Submarine tender Chōgei, Submarine I-201, I-202, I-203
- Submarine Flotilla 1 : Submarine I-13, I-400, I-401
- Submarine Flotilla 15 : Submarine I-36, I-47, I-53, I-58
- Submarine Flotilla 16 : Submarine I-369, I-372, Ha-101, Ha-102, Ha-104
- Submarine Flotilla 34 : Submarine Ha-109
Commanders of the IJN 6th Fleet
Commander in chief
| |
Rank |
Name |
Date |
| 1 |
Vice-Admiral |
Noboru Hirata |
15 November 1940 |
21 July 1941 |
| 2 |
Vice-Admiral |
Mizumi Shimizu |
21 July 1941 |
16 March 1942 |
| 3 |
Vice-Admiral |
Marquis Teruhisa KomatsuMarquis was an admiral in the Imperial Japanese Navy in World War II.Born as HIH Kitashirakawa-no-miya Teruhisa, as the younger son of HIH Prince Kitashirakawa Yoshihisa, his title was devolved from royal status that that of the kazoku peerage in 1910 in order to preserve to Komatsu family line,...
|
16 March 1942 |
21 June 1943 |
| 4 |
Vice-Admiral |
Takeo Takagiwas an admiral in the Imperial Japanese Navy during World War II.-Biography:Takagi was a native of Iwaki city, Fukushima prefecture. He was a graduate of the 39th class of the Imperial Japanese Naval Academy, ranking 17th of 148 cadets in 1911...
|
21 June 1943 |
10 July 1944 |
| 5 |
Vice-Admiral |
Shigeyoshi Miwa, was an admiral in the Imperial Japanese Navy during World War II. He commanded the Japanese submarine forces during the attack on Pearl Harbor.-Biography:...
|
10 July 1944 |
1 May 1945 |
| 6 |
Vice-Admiral |
Marquis Tadashige DaigoMarquis was an admiral in the Imperial Japanese Navy during World War II.-Biography:Born in Chiyoda, Tokyo into a kuge family of court nobility related to the Fujiwara aristocracy, Daigo was a graduate of the Gakushuin Peers' school. He went on to graduate from the 40th class of the Imperial...
|
1 May 1945 |
15 September 1945 |
Chief of staff
| |
Rank |
Name |
Date |
| 1 |
Vice-Admiral |
Hisashi Ichioka |
15 November 1940 |
6 January 1941 |
| 2 |
Vice-Admiral |
Hisashi Mito |
6 January 1941 |
22 October 1942 |
| 3 |
Rear Admiral |
Hisagoro Shimamoto |
22 October 1942 |
15 November 1943 |
| 4 |
Rear Admiral |
Kozo Nishina |
15 November 1943 |
21 December 1944 |
| 5 |
Rear Admiral |
Hankyu Sasaki |
21 December 1944 |
15 September 1945 |