Japanese battleship Mutsu
Encyclopedia
Mutsu Province
was an old province of Japan in the area of Fukushima, Miyagi, Iwate and Aomori prefecture and the municipalities of Kazuno and Kosaka in Akita Prefecture...
, as per Japanese ship naming conventions
Japanese ship naming conventions
Japanese ship naming conventions are different from those in the West. Japanese warships have never been named after people. Prior to World War II, Japanese ship naming conventions underwent several changes before being settled.- Merchant ships :...
, was 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...
's (IJN) second Nagato
Nagato class battleship
The were two battleships of the Imperial Japanese Navy. The name Nagato comes from the Nagato province. They were the first battleships to be built entirely in Japan...
class battleship. When commissioned in 1921, she and her sister-ship were the first battleships in the world with 16 inch (410 mm) guns and were considered the Japanese navy equivalents of the British Navy’s Queen Elizabeth
Queen Elizabeth class battleship
The Queen Elizabeth-class battleships were a class of five super-dreadnoughts of the Royal Navy. The lead ship was named after Elizabeth I of England...
class. At the time of their completion in 1920–21, their armament, armour and speed made them the most powerful capital ships in the world and they remained the most powerful battleships in the Imperial Japanese Navy until the completion of the Yamato class. It was not until 1937 that the US Navy became aware that their actual speed was considerably higher than the 23 knots they had previously assumed, which resulted in a redesign of the South Dakota
South Dakota class battleship (1939)
The South Dakota-class was a group of four fast battleships built by the United States Navy. They were the second class of battleships to be named after the 40th State; the first class was designed in the 1920s and canceled under the terms of the Washington Naval Treaty. The class comprised four...
class to provide them with a higher speed.
The Nagato class were extensively modified in the 1920s and 1930s after the Washington Naval Treaty
Washington Naval Treaty
The Washington Naval Treaty, also known as the Five-Power Treaty, was an attempt to cap and limit, and "prevent 'further' costly escalation" of the naval arms race that had begun after World War I between various International powers, each of which had significant naval fleets. The treaty was...
of 1922 limited the battleship tonnage of the Japanese (and other) navies and allowed no new construction for several years. As a result of the treaty, they were the last battleships built by Japan until the Yamato class battleship
Yamato class battleship
The were battleships of the Imperial Japanese Navy constructed and operated during World War II. Displacing at full load, the vessels were the heaviest and most powerfully armed battleships ever constructed. The class carried the largest naval artillery ever fitted to a warship, nine naval...
s of the late 1930s.
The sparing of Mutsu was a condition of the Japanese Government's signing the Washington Naval Treaty
Washington Naval Treaty
The Washington Naval Treaty, also known as the Five-Power Treaty, was an attempt to cap and limit, and "prevent 'further' costly escalation" of the naval arms race that had begun after World War I between various International powers, each of which had significant naval fleets. The treaty was...
. Not only was she was the most modern and powerful ship in the fleet at the time, she was also the first battleship designed by Japanese naval architects. Her construction had been funded by public subscription, most notably Japanese school children, which meant that she was greatly admired by the Japanese people. As a result it would have been domestically and politically unacceptable to scrap her so soon after her construction. The battleship Settsu
Japanese battleship Settsu
The was the second of the two-ship Kawachi-class of dreadnought battleships of the Imperial Japanese Navy. She was built at Kure Naval Arsenal and launched in 1910...
was decommissioned instead.
Design
She was authorised in 1917 and allocated the design number A-102 the Mutsu was designed by Captain Yuzuru HiragaYuzuru Hiraga
- External links :...
.
Construction
Laid down at the Yokosuka Naval Arsenal on 1 June 1918, the Mutsu was launched on 31 May 1920, and commissioned on 24 October 1921.As commissioned
Upon her completion the Mutsu had a displacement of 34,116 tons while her 21 coal fired boilers powered four geared Gihon turbines that developed a total of 82,000 shp, which allowed her to reach a trial speed of 26.728 knots (14.6 m/s).Despite the front funnel being 2 metres (6.6 ft) higher than the rear one to reduce smoke interference to the gunnery control positions of the front mast, operational experience led to the front funnel being fitted with a smoke deflector in 1922 shortly after test trials were completed. To further reduce smoke interference, the top of the fore funnel was curved back 8 metres (26.2 ft) between August 1924 and March 1925. The Mutsu was fitted with a clipper bow in 1927.
Four twin dual purpose 5-inch (127-mm) HA (high angle) guns were installed in 1932, the existing 3-inch (76-mm) AA guns were removed.
Reconstruction and modernization
She underwent major reconstruction at the Yokosuka Navy Yard between 5 September 1934 and 30 September 1936, in which her hull was lengthened to 737 feet (224.6 m) and anti-torpedo bulges and a triple bottom were added. Horizontal armour was increased over the engine room and magazines and additional armour was also fitted to the faces, sides and tops of her main turrets, the barbette armour was also strengthened. Additions to the fore-mast led to her acquiring the distinctive pagoda mastPagoda Mast
The Pagoda mast was a type of superstructure that was common on Japanese capital ships that were reconstructed during the 1930s in a bid to improve their fighting performance...
that became the distinguishing feature of Japanese battleships of her era. She lost her submerged torpedo tubes and two of her upper deck secondary guns. The elevation of her main 16-inch guns was increased from −5 / +30 to −3 / +43 degrees, which increased their maximum range to 33,930 yards (31,025 m) when firing a 2,069 lbs shell. (938.5 kg) HE shell and 42,350 yards (38,725 m) when firing a 2,249 lbs projectile or an (1,020 kg) APC (armour-piercing capped) shell. The elevation of the remaining 5.5-inch guns was increased to 35 degrees. Eight 127 mm dual-purpose guns in four twin mounts and twenty Type 96 25mm anti-aircraft guns in ten twin mounts were added to increase her anti-aircraft protection. A 19.6 metre long Kure Type No. 2 Model 5 catapult and a collapsible crane were fitted forward of "C" turret for three Nakajima
Nakajima Aircraft Company
The Nakajima Aircraft Company was a prominent Japanese aircraft manufacturer throughout World War II.-History:...
E4N2 floatplanes which were to be carried for observation purposes.
All twenty original coal-fired steam boilers were replaced by four new large Kampon and six smaller re-built oil fired units, which developed 92,000 shp, extended the range and allowed her to maintain close to her original speed despite the increased drag of the torpedo bulges and the weight of the additional armour which had increased her standard displacement to 42,785 tons. During trials on 27 July 1936 she attained a speed of 25.283 knots. The changes in her boilers allowed her front funnel to be removed although her rear funnel was enlarged.
The completion of her reconstruction was her last significant modification until 1941 when she was fitted with external degaussing coils and the anti-torpedo bulges were filled with crushing tubes.
Service and World War II
After commissioning the Mutsu served in the First Battleship Division of the First Fleet. Upon completion of her modernisation she rejoined the First Battleship Division.During World War II Mutsu saw limited action, spending much of her time in home waters. Mutsu, as part of a covering force for the Pearl Harbor
Attack on Pearl Harbor
The attack on Pearl Harbor was a surprise military strike conducted by the Imperial Japanese Navy against the United States naval base at Pearl Harbor, Hawaii, on the morning of December 7, 1941...
task force forayed from Hashirajima
Hashirajima
is an island in southern Hiroshima Bay of the Inland Sea, Yamaguchi Prefecture, Japan. Located 26 kilometers southeast of Iwakuni, it is part of the Kutsuna Islands within the Bōyō Islands group....
to the Bonin Islands from 8 to 13 December 1941, in company with the light carrier Hosho
Japanese aircraft carrier Hosho
Hōshō |phoenix]]") was the world's first commissioned ship that was designed and built as an aircraft carrier,The HMS Argus pre-dated Hōshō and had a long landing deck, but was designed and initially built as an ocean liner. and the first aircraft carrier of the Imperial Japanese Navy...
and the First Fleet's Battleship 2 division's Ise
Japanese battleship Ise
, was the lead ship of the two-vessel Ise-class battleship of the Imperial Japanese Navy, which saw combat service during the Pacific War. Ise was named after Ise Province, one of the traditional provinces of Japan, now part of Mie Prefecture....
, Hyuga
Japanese battleship Hyuga
Hyūga , named for Hyūga Province in Kyūshū, was an of the Imperial Japanese Navy laid down by Mitsubishi on 6 May 1915, launched on 27 January 1917 and completed on 30 April 1918. She was initially designed as the fourth ship of the , but was heavily redesigned to fix shortcomings...
, Fusō
Japanese battleship Fuso
The Japanese battleship Fusō , was a part of the Imperial Japanese Navy, the lead ship of the Fusō-class. She was laid down by the Kure Kaigun Koshō on 11 March 1912, launched on 28 March 1914 and completed on 18 November 1915...
, and Yamashiro
Japanese battleship Yamashiro
Yamashiro was the Imperial Japanese Navy's second Fusō-class battleship, and was laid down at the Yokosuka Naval Arsenal on November 20, 1913, launched on November 3, 1915, and commissioned on March 31, 1917. She was the first Japanese vessel equipped with aircraft catapults...
, escorted by light cruisers and destroyers. The group saw no action.
The Mutsu departed Hashirajima as part of the Battleship Division First Fleet's Main Body under the command of Admiral Isoroku Yamamoto
Isoroku Yamamoto
was a Japanese Naval Marshal General and the commander-in-chief of the Combined Fleet during World War II, a graduate of the Imperial Japanese Naval Academy and a student of Harvard University ....
on 29 May 1942 in company with the battleships Yamato
Japanese battleship Yamato
, named after the ancient Japanese Yamato Province, was the lead ship of the Yamato class of battleships that served with the Imperial Japanese Navy during World War II. She and her sister ship, Musashi, were the heaviest and most powerfully armed battleships ever constructed, displacing...
, Nagato
Japanese battleship Nagato
Nagato was a battleship of the Imperial Japanese Navy; the lead ship of her class. She was the first battleship in the world to mount 16 inch guns, her armour protection and speed made her one of the most powerful capital ships at the time of her commissioning.She was the flagship of Admiral...
, the aircraft carrier Hosho
Japanese aircraft carrier Hosho
Hōshō |phoenix]]") was the world's first commissioned ship that was designed and built as an aircraft carrier,The HMS Argus pre-dated Hōshō and had a long landing deck, but was designed and initially built as an ocean liner. and the first aircraft carrier of the Imperial Japanese Navy...
, the cruiser Sendai
Japanese cruiser Sendai
was a Sendai-class light cruiser in the Imperial Japanese Navy. She was named after the Sendai River in southern Kyūshū.-Background:Sendai was the lead ship of the three vessels completed in her class of light cruisers, and like other vessels of her class, she was intended for use as the flagship...
, nine destroyers and four auxiliary vessels to provide support to Operation “MI”, the Japanese Navy’s attempt to take the island of Midway
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...
. During the resulting battle
Battle of Midway
The Battle of Midway is widely regarded as the most important naval battle of the Pacific Campaign of World War II. Between 4 and 7 June 1942, approximately one month after the Battle of the Coral Sea and six months after Japan's attack on Pearl Harbor, the United States Navy decisively defeated...
the Mutsu remained with the main body 300 miles behind Vice Admiral Nagumo's First Carrier Striking Force, and did not engage US forces. At the end of the battle the Mutsu joined up with the retiring Carrier Striking Force on 5 June and took aboard about one-half of the survivors from the carriers Akagi
Japanese aircraft carrier Akagi
Akagi was an aircraft carrier of the Imperial Japanese Navy , originally begun as an . She was converted while still under construction to an aircraft carrier under the terms of the Washington Naval Treaty...
, Kaga
Japanese aircraft carrier Kaga
Kaga was an aircraft carrier of the Imperial Japanese Navy , named after the former Kaga Province in present-day Ishikawa Prefecture...
, Soryu
Japanese aircraft carrier Soryu
was an aircraft carrier of the Imperial Japanese Navy. During the Second World War, she took part in the attack on Pearl Harbor, Wake Island, Port Darwin and raids in the Indian Ocean before being sunk at the Battle of Midway.-Design:...
and Hiryu
Japanese aircraft carrier Hiryu
was a modified Sōryū-class aircraft carrier of the Imperial Japanese Navy. She was one of the carriers that began the Pacific War with the attack on Pearl Harbor...
that had been picked up earlier by covering destroyers and also refuelled a number of destroyers. On 14 June the Mutsu returned to her home anchorage in Hashirajima.
In July the Mutsu was transferred from the Battleship Division 1 to the Battleship Division 2 which was allocated to training and 'standby alert' duties.
The Mutsu departed Yokosuka accompanied by the cruisers Atago
Japanese cruiser Atago
was one of four Takao-class heavy cruisers, designed to be an improvement over the previous Myōkō-class design. These ships were fast, powerful, and heavily armed. The Takao-class ships were approved under the 1927 fiscal year budget as part of the Imperial Japanese Navy's strategy of the Decisive...
, Takao
Japanese cruiser Takao
was the first of four Takao-class heavy cruisers, designed to be an improvement over the previous Myōkō-class design. The Myōkō had proved to be unstable and required modifications, which were incorporated into the Takao design....
, Maya
Japanese cruiser Maya
was one of four Takao-class heavy cruisers, designed to be an improvement over the previous Myōkō-class design. These ships were fast, powerful and heavily armed, with enough firepower to hold their own against any cruiser in any other navy in the world...
, Haguro
Japanese cruiser Haguro
|-External reference links: -External links:**...
, Yura
Japanese cruiser Yura
The was the third 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 the flagship of a destroyer flotilla. She was named after the Yura River near Kyoto, Japan.-Early career:...
, Myoko
Japanese cruiser Myoko
was the name-ship of the four-member of heavy cruisers of the Imperial Japanese Navy — the other ships of the class being the Nachi, Ashigara, and Haguro....
, the seaplane tender Chitose
Japanese aircraft carrier Chitose
was a light aircraft carrier of the Imperial Japanese Navy during World War II. It should not be confused with the earlier cruiser of the same name. First laid down as a seaplane tender in 1934 at Kure Navy yard, the ship originally carried Kawanishi E7K Type 94 "Alf" and Nakajima E8N Type 95...
and escorting destroyers on 11 August to support operations during the Guadalcanal Campaign
Guadalcanal campaign
The Guadalcanal Campaign, also known as the Battle of Guadalcanal and codenamed Operation Watchtower by Allied forces, was a military campaign fought between August 7, 1942 and February 9, 1943 on and around the island of Guadalcanal in the Pacific theatre of World War II...
. The task force arrived at the major Japanese base 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 17 August 1942. On 20 August, while sailing from Truk to rendezvous with the main body of Vice Admiral Nagumo's Third Fleet, the Mutsu, the cruiser “Atago’’
Japanese cruiser Atago
was one of four Takao-class heavy cruisers, designed to be an improvement over the previous Myōkō-class design. These ships were fast, powerful, and heavily armed. The Takao-class ships were approved under the 1927 fiscal year budget as part of the Imperial Japanese Navy's strategy of the Decisive...
and escorting destroyers, in response to a flying boat detecting the escort carrier USS Long Island
USS Long Island (CVE-1)
USS Long Island was lead ship of her class and the first escort carrier of the United States Navy...
ferrying aircraft, attempted to locate the American ship. No contact was made.
During the battle of the Eastern Solomon
Battle of the Eastern Solomons
The naval Battle of the Eastern Solomons The naval Battle of the Eastern Solomons The naval Battle of the Eastern Solomons (also known as the Battle of the Stewart Islands and, in Japanese sources, as the , took place on 24–25 August 1942, and was the third carrier battle of the Pacific campaign...
islands on 27 August, Mutsu fired four shells at tracking enemy aircraft during what was her first and only action of the war. Following her return to Truk a group of skilled AA gunnery officers and men were detached from the Mutsu to serve as instructors to ground-based naval anti-aircraft gunners stationed in 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...
. During her time at Truk the Mutsu off-loaded surplus fuel to the fleet oil tanker Kenyo Maru which allowed the tanker to refuel other ships involved in Guadalcanal operations.
On 7 January 1943, the Mutsu steamed from Truk via 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...
to return to Japan in the company of the carrier Zuikaku
Japanese aircraft carrier Zuikaku
Zuikaku was a Shōkaku-class aircraft carrier of the Imperial Japanese Navy. Her complement of aircraft took part in the attack on Pearl Harbor that formally brought the United States into the Pacific War, and she fought in several of the most important naval battles of the war, finally being sunk...
, the cruiser Suzuya and the destroyers Inazuma, Isonami and Ariake
Japanese destroyer Ariake
was the fifth of six destroyers, built for the Imperial Japanese Navy under the Circle One Program . Three were laid down in JFY 1931 and the next three in JFY 1933...
. Upon her return to Hashirajima, Mutsu resumed 'standby alert' duties.
The Mutsu left Hashirajima for Kure
Kure
Kure can refer to:*KURE, a radio station in Ames, Iowa*Kure Software Koubou, Japanese video game development company*Kure, Hiroshima , a city in Hiroshima prefecture, Japan**Kure Line, a rail line in the city...
on 13 April, where in response to the situation
Battle of the Komandorski Islands
The Battle of the Komandorski Islands was one of the most unusual engagements of World War II. It was a naval battle which took place on 27 March 1943 in the North Pacific area of the Pacific Ocean, near the Soviet Komandorski Islands.-Background:...
in the Komandorski Islands, she took aboard a full load of ammunition and supplies and prepared to participate in a sortie to reinforce the Japanese garrisons in the Aleutian Islands, but the situation changed and she was never dispatched.
Loss
On Tuesday 8 June 1943 the Mutsu was moored at the Battleship Division 2 flagship buoy No.2 in the Hashirajima fleet anchorage approximately 3 km (1.9 mi) south-west of the island of Hashirajima and just to the west of Mitsuhima island in the Inland Sea, hosting 113 flying cadets and 40 instructors from the Tsuchiura Naval Air Group on a familiarization tour. At 12:13 the magazine of her No. 3 turret exploded. The explosion was so severe that it instantly sheared the stern from the ship forward of No. 3 turret, causing major flooding in the boiler rooms and main engine room. The 535 feet (163.1 m) forward section of the ship rolled to starboard and sank almost immediately. The stern section upended and remained floating until about 0200 hours on 9 June before sinking, coming to rest just a few hundred feet south of the main wreck.The battleship Fuso
Japanese battleship Fuso
The Japanese battleship Fusō , was a part of the Imperial Japanese Navy, the lead ship of the Fusō-class. She was laid down by the Kure Kaigun Koshō on 11 March 1912, launched on 28 March 1914 and completed on 18 November 1915...
immediately launched two boats which, together with assistance from the destroyers Tamanami
Japanese destroyer Tamanami
was a of the Imperial Japanese Navy.On 7 July 1944, Tamanami was escorting the tanker Kokuyo Maru from Singapore towards Manila, Philippines. She was torpedoed by , west-southwest of Manila . Tamanami blew up and sank with all hands....
, Wakatsuki
Japanese destroyer Wakatsuki
was an Akizuki-class destroyer of the Imperial Japanese Navy. Her name means "Young Moon".Wakatsuki participated in rescuing sailors from two of the aircraft carriers that participated in the attack on Pearl Harbor: and when each was sunk by US forces.On 11 November 1944, Wakatsuki was...
, the cruisers Tatsuta and Mogami
Japanese cruiser Mogami
was the lead ship in the four-vessel Mogami-class of heavy cruisers in the Imperial Japanese Navy. It was named after the Mogami River in Tohoku region of Japan. The Mogami class ships were constructed as "light" cruisers with 5 triple 6.1" DP guns...
, were able to rescue 353 survivors from the 1,474 crew members and visitors aboard Mutsu, giving a loss of 1,121. Only 13 of the visiting flying cadets/instructors were among the survivors. During the initial and later salvage operations, lasting until 1978, all but 272 of the bodies were recovered. Since 1963, a memorial service is held every year on 8 June in Tôwa Chô in honour of the crew.
After the explosion, as the rescue operations commenced, the fleet was mobilized and the area was combed for Allied submarines and X-craft, but no traces were found.
To avert the potential damage to morale of the loss of a battleship coming so soon after the string of recent setbacks in the war effort, Mutsus loss was declared a state secret. Mass cremations of recovered bodies began almost immediately after the sinking. Captain Miyoshi's body was recovered from his cabin by divers on 17 June, his wife was not officially notified until 6 January 1944, how he had died was not mentioned. Both he and his second in command, Captain Ono Koro, were posthumously promoted to Rear Admiral, which was normal Japanese Navy practice. 39 wounded survivors were sent to a secluded hospital on Mitsukoshima.
To further prevent rumours from spreading, healthy and recovered survivors were re-assigned to various garrisons in the Pacific Ocean. Some of the survivors were sent to Truk in the Caroline Islands
Caroline Islands
The Caroline Islands are a widely scattered archipelago of tiny islands in the western Pacific Ocean, to the north 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...
to form the 41st Guard Force. Another 150 were sent to 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...
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...
where most were killed in 1944 during the battle for the island
Battle of Saipan
The Battle of Saipan was a battle of the Pacific campaign of World War II, fought on the island of Saipan in the Mariana Islands from 15 June-9 July 1944. The Allied invasion fleet embarking the expeditionary forces left Pearl Harbor on 5 June 1944, the day before Operation Overlord in Europe was...
.
At the time of the explosion Mutsus magazine contained a number of 16-inch Type 3 "Sanshikidan" incendiary shells, which had caused a fire at the Sagami arsenal
Sagami General Depot
Sagami General Depot is a United States Army post located in the city of Sagamihara, in Kanagawa Prefecture, Japan, about southwest of Tokyo.-The Depot:Sagami General Depot is located in the city of Sagamihara, Kanagawa Prefecture, Honshu, Japan...
several years earlier due to improper storage. Because they might have been the cause of the explosion, the Minister of the Navy, Admiral Shimada Shigetaro
Shigetaro Shimada
was an admiral in the Imperial Japanese Navy during World War II. He also served as Navy Minister-Biography:A native of Tokyo, Shimada graduated from the 32nd class of the Imperial Japanese Naval Academy in 1904...
, immediately ordered the removal of Type 3 shells from all IJN ships carrying them, until the conclusion of the investigation into the loss.
Investigations into the loss
An official accident commission led by Admiral Shiozawa Koichi was convened three days after the sinking to investigate the loss, with its preliminary conclusions issued on 25 June 1943. The commission considered a number of possible causes:- Sabotage by enemy secret agents. Given the heavy security at the anchorage and lack of claims of responsibility by the Allies, this could be discounted.
- Sabotage by a disgruntled crewmen. While no individual was named in the commission’s final report, its conclusion was that the cause of the explosion was most likely a suicidal crewman in No. 3 turret who had recently been accused of theft.
- A midget or fleet submarine attack. Extensive searches immediately following the sinking had failed to detect any enemy submarine and the Allies had made no attempt at claiming the enormous propaganda value of sinking a capital ship in her home anchorage; consequently, this possibility was quickly discounted. Eyewitnesses also spoke of a reddish-brown fireball which indicated a magazine explosion and was confirmed during exploration of the wreck by divers.
- Accidental explosion within a magazine. While the Mutsu carried a large number of projectiles, immediate suspicion focused on the Type 3 anti-aircraft shell as it had been suspected of causing a fire before the war at the Sagami arsenal. Known as a "sanshiki-dan" or “sankaidan” these were fired by the main armament and contained 900 to 1,200 25 mm diameter steel tubes (depending upon sources), each containing an incendiary charge. Tests were conducted at Kamegakubi Naval Proving Ground on several shells salvaged from No. 3 turret and on shells from the previous and succeeding manufacturing batches. Using a specially built model of the Mutsu’s No. 3 turret, the experiments were unable to induce the shells to explode under any perceived service or artificial service conditions.
- Fire. Compared with other nation’s warships in wartime service, Japanese battleships contained a large amount of peacetime inflammable materials including untreated bedding, wooden decking, wooden furniture and wooden sheathing (for insulation). When she had been modernised in the 1930s, some of the Mutsu’s electrical wiring may have dated from her original commissioning. While fire in the secure magazines was a very remote possibly, a fire in an area adjacent to the Number 3 magazine could have raised the temperature to a sufficient enough level to ignite the highly sensitive black-powder primer stored in the magazine and thus instigate the explosion.
Salvage operations
Divers were brought into the area to retrieve bodies and to assess the damage to the ship. Prior to diving on the wreck they were allowed to familiarize themselves onboard the Mutsu’s sister-ship, the Nagato.Despite initial negative reports from the divers the leadership of the Japanese Navy gave serious consideration to raising the remains of the Mutsu and possibly rebuilding her. To this end a dive was made from dive-boat No 3746 and a Nishimura
Nishimura
Nishimura is a Japanese surname. It may refer to:*Akihiro Nishimura , a Japanese politician of the Liberal Democratic Party*Akihiro Nishimura , a former Japanese football player...
-type search and rescue and research submersible on 17 June. This 7-man vessel, with a nominal 1-hour oxygen supply, snagged on the wreck and the crew nearly suffocated after two hours submerged before they managed to free themselves. Because of this risk the remainder of the inspections of the wreck were carried out by divers. After two months of undersea investigation, the navy reached the conclusion that the ship could not be recovered.
On 1 September 1943 the Mutsu was formally removed from the Navy List. In July 1944 the oil-starved Japanese Navy conducted Operation “Take” (Bamboo) which recovered 580 tons of fuel from the wreck.
The US Navy inspected the wreck in 1947. In the early 1950s, the United States occupation administration formally returned the wreck to the Japanese government, which allowed further salvage operations to be undertaken. This led in 1953, to the 1.2-metre diameter chrysanthemum crest, which had adorned the ship’s bow, being raised and in 1963 one of the 5.5-inch (140 mm) casemate guns.
On 20 March 1970, the Fukada Salvage Company acquired the rights to the wreck and undertook salvage operations until 1978, when the operation ended with about 75% of the ship recovered. Operations commencing with the raising of the No. 4 turret in 1970, were witnessed by Captain Miyoshi's widow. No. 3 turret was raised intact in September 1971.
In 1995, it was declared by the Mutsu Memorial Museum that there would be no more salvage operations. The only significant portion of the ship that remains is a 35 metre long section running from the bridge structure to and including the No.1 turret area. The highest portion of the ship is 12 metres below the surface.
Pieces recovered over the years can be viewed at various museums, memorials and shrines in Japan:
- Many artefacts are displayed at the Mutsu Memorial Museum in Tôwa Chô. This is a successor to a local museum funded by the town of Suo-Oshima which opened in July 1970. To make room for a new road, this museum was moved in April 1994 to a new building.
- The fully restored No. 4 turret is on display at the former naval academy at Etajima.
- The left-side 16-inch (410mm) gun from No. 3 turret is displayed outside the Yamato MuseumYamato MuseumThe Yamato Museum is a nickname of the "Kure Maritime Museum" in Kure, Hiroshima, Japan.-History:The museum opened on April 23, 2005. It is nicknamed the Yamato Museum due to the display in the lobby of the large model ship Yamato Hiroba, a 1/10 scale model of the Japanese battleship Yamato...
in Kure in Daiwa Park. This park also contains one of Mutsu’s 3.5 metre diameter propellers, a rudder and an anchor. - One 16-inch (410mm) gun from No. 3 turret is on display at the Museum of Maritime Science, Shinagawa, in Tokyo.
- One of the 5.5-inch (140 mm) secondary guns is displayed at Yasukuni MuseumYushukanThe is a Japanese military and war museum located within Yasukuni Shrine in Chiyoda, Tokyo. As a museum maintained by the shrine, which is dedicated to the souls of soldiers who died fighting on behalf of the Emperor of Japan, the museum contains various artifacts and documents concerning Japanese...
in Tokyo. This gun had been raised in 1963. - A rudder and a section of propeller shaft were on display at the Arashiyama Art Museum until it closed circa 1991. Their current whereabouts are now unknown.