SENKAN!

3 December 1941:
Returns to Hashirajima. Anchors in readiness condition.

8 December 1941: Operation "Z" – The Attack on Pearl Harbor:
BatDiv 1 sorties from Hashirajima to the Bonin Islands with the First Fleet's BatDiv 2's ISE, FUSO, YAMASHIRO, HYUGA, CarDiv 3's light carriers HOSHO and ZUIHO, escorted by DesDiv 21's WAKABA, NENOHI, HATSUHARU and HATSUSHIMO and DesDiv 27's ARIAKE, YUGURE, SHIRATSUYU, SHIGURE, MIKAZUKI and YUKAZE.

11 December 1941:
At 0600 the squadron changes course to the west and and 0900 to the NW, to return to Hashirajima. MUTSU suffers a steering gear failure, caused by the sudden loss of pressure in the hydraulic telemotor system, and lags behind the force for 15 minutes.

13 December 1941:
BatDiv 1 returns to Hashirajima, maintains standby alert. During this period, BatDiv 1 is involved in training, exercises and gunnery practice in the western Inland Sea. Minor repairs are carried out at Kure.

20 December 1941:
After 2140, Navy Minister Shimada Shigetaro (currently visiting Admiral Yamamoto Isoroku aboard NAGATO) is piped aboard MUTSU where he spends the night to return to NAGATO the following morning.

18 January 1942:
Off Kurahashi Island, Inland Sea, 15 miles SW of Kure. After 1830 MUTSU acts as a target tug during the new battleship YAMATO's gunnery trials.

19 January 1942:
After a night stop at Agenosho Bay, YAMATO and MUTSU return to Hashirajima at 1130, escorted by destroyers MIKAZUKI and YAKAZE.

12 February 1942:
YAMATO joins BatDiv 1 with MUTSU and NAGATO. The Combined Fleet's flag is transferred from NAGATO to YAMATO.

19 February 1942:
At 0600, BatDiv 1 departs Hashirajima for joint maneuvers in Iyo Nada, Inland Sea. MUTSU departs as the 2nd unit of BatDiv 1.

28 February 1942:
Departs for Agenosho Bay.

1 March 1942:
Returns to Hashirajima.

5 March 1942:
At Kure for maintenance.

27 March 1942:
BatDiv 1 departs Hashirajima for training, returns to Tokuyama Bay.

30 March 1942:
At Hashirajima.

7 April 1942:
At Kure.

5 May 1942:
BatDiv 1's MUTSU and NAGATO depart Hashirajima for gunnery practice in the Iyo Nada with BatDiv 2. HYUGA's No. 5 turret gun blows up. She departs for Kure with FUSO as escort. MUTSU and other battleships return to Hashirajima.

11 May 1942:
BatDiv 1 departs Hashirajima for gunnery and AA practice in the Iyo Nada. Returns that night.

15 May 1942:
Batdiv 1 departs Kure for three days of exercises with CruDiv 7's MOGAMI, MIKUMA, KUMANO and the SUZUYA in the Inland Sea.

19 May 1942:
The First Fleet and the First Air Fleet depart Hashirajima for two days of maneuvers at sea.

23 May 1942:
The fleets return to Hashirajima.

29 May 1942:
The First Fleet's Main Body: BatDiv 1's YAMATO, NAGATO and MUTSU departs Hashirajima with the light carrier HOSHO, the seaplane tenders CHIYODA and NISSHIN, Supply Group No. 1's oilers NARUTO and TOEI MARU and DesRon 3's light cruiser SENDAI with nine destroyers.

4 June 1942: Operation "MI" - The Battle of Midway:
The Main Body remains 300 miles behind Vice Admiral Nagumo's First Carrier Striking Force and does not engage U.S. forces.

5 June 1942:
The Main Body joins up with the remnants of Vice Admiral (Admiral, posthumously) Nagumo Chuichi's (former CO of YAMASHIRO) retiring Carrier Striking Force. MUTSU takes aboard about one-half of the survivors from the carrier AKAGI who had been picked up earlier by destroyers ARASHI and NOWAKI. MUTSU refuels DesRons 3 and 10's destroyers.

14 June 1942:
The Main Body returns to Hashirajima.

20 June 1942:
Captain (later Rear Admiral) Yamazumi Teijiro (44)(former CO of MYOKO) is appointed the CO.

3 July 1942:
At Tokuyama, probably to refuel.

6 July 1942:
Returns to Hashirajima.

14 July 1942:
Hashirajima. The First Fleet is reorganized. MUTSU and NAGATO are transferred from the Combined Fleet's BatDiv 1 to Vice Admiral Shimizu Mitsumi's (former CO of ISE) First Fleet in BatDiv 2 with YAMASHIRO, FUSO, ISE and HYUGA. BatDiv 2 performs standby alert and training missions.

18 July 1942:
Departs Hashirajima. Arrives at Kure.

22-29 July 1942:
Kure. Dry-docked for hull maintenance.

3 August 1942:
Returns to Hashirajima.

9 August 1942:
MUTSU is attached to Vice Admiral (later Admiral) Kondo Nobutake's (former CO of KONGO) Second Fleet, Advance Force for Guadalcanal operations.

11 August 1942:
Departs Yokosuka for Truk with Kondo's Advance Force: CruDiv 4's ATAGO (F), TAKAO and MAYA, CruDiv 5's HAGURO and MYOKO, CarDiv 11's seaplane tender CHITOSE, DesRon 4's light cruiser YURA and five destroyers.

12 August 1942:
Admiral Yamamoto orders the Advance Force to redeploy E of the Bonin Islands to intercept a suspected task force (in reality the light cruiser USS BOISE (CL-47), conducting a raid on the IJN picket line E of Honshu). MUTSU refuels DesRon 4's destroyers at sea.

After no carriers are sighted, Vice Admiral Kondo soon resumes the voyage to Truk.

17 August 1942:
The Advance Force arrives at Truk. MUTSU and DesDiv 2's HARUSAME, MURASAME and SAMIDARE are assigned to the Fleet Train of the Support Force. The Fleet Train supports Kondo's Advance Force and Vice Admiral Nagumo's Third Fleet.

20 August 1942:
Admiral Yamamoto dispatches the Advance Force to rendezvous with Nagumo's Main Body, currently en route from Kure. Kondo leaves the MUTSU - unable to keep pace with his heavy cruisers - behind at Truk.

21 August 1942:
MUTSU departs Truk in company of HARUSAME, MURASAME and SAMIDARE to rendezvous with Kondo's Advance Force.

24 August 1942: The Battle of the Eastern Solomons:
N of Stewart Islands (now Sikaiana Atoll). At 1755, two VB-3's SBD-3 "Dauntlesses" from TF 11's USS SARATOGA (CV-3) attack a "MUTSU-class battleship" escorted by "four heavy cruisers and a dozen destroyers", claiming the battleship set on fire. In reality their target (seaplane carrier CHITOSE) is damaged by near misses.

At 1915 (local), Kondo, hoping to intercept the crippled USS ENTERPRISE (CV-6) with his heavy cruisers after sundown, orders MUTSU and her escorts to return to port.

5 September 1942:
MUTSU and her escorts return to Truk.

9 September 1942:
Truk anchorage No. 1. Around 0950, destroyer AKIZUKI reports the sighting of a periscope south of Fanos Island. Several patrol vessels are dispatched to hunt down the intruder. MUTSU and YAMATO are temporarily redirected to a new anchorage south of Dublon Island.

MUTSU is incorporated into the Main Body of the Guadalcanal Operation Force.

20 September 1942:
Defensive anti-aircraft fire in the Rabaul area is unskilled and uncontrolled, so competent AA gunnery officers and men from MUTSU and YAMATO are dispatched from Truk to Rabaul to serve as instructors.

22 September 1942:
Truk. Thereafter, MUTSU participates in battle exercises.

11 October 1942:
Truk. Following the departure of the units of the Second and Third Fleets, after 1200 battleships MUTSU, YAMATO, CruDiv 9, repair ship AKASHI and other units are transferred to a new fleet anchorage south of Moen Island.

18 October 1942:
Truk. Fleet oiler KENYO MARU, attached to the Advance Force, arrives empty. MUTSU and YAMATO each transfer 4,500-tons of fuel to the oiler so that she can refuel fleet units for the Guadalcanal operations.

9 November 1942:
Truk. MUTSU and YAMATO provide rice for Kondo's outbound Advance Force.

7 January 1943:
MUTSU departs Truk for Yokosuka, escorted by CruDiv 7's SUZUYA and DesDiv 20's AMAGIRI.

12 January 1943:
MUTSU arrives at Yokosuka.

12-28 January 1943:
Returns to Hashirashima. Resumes standby alert.

29 January-6 February 1943:
Yokosuka. Dry-docked in Drydock No. 5 for hull cleaning and maintenance. The aircraft complement is changed to two Mitsubishi F1M2 "Pete" floatplanes.

15 February 1943:
Departs Yokosuka for Hashirajima.

16 February 1943:
MUTSU and destroyers YAMAGUMO, HATAKAZE and NOKAZE are briefly joined by minelayer YURIJIMA and subchaser CH-37. Arrives at Hashirajima and resumes training duties thereafter.

4 March 1943:
Departs Hashirajima. Arrives at Kure.

8 March 1943:
Departs Kure. Returns to Hashirajima.

10 March 1943:
Captain (Rear Admiral, posthumously) Miyoshi Teruhiko (43)(former CO of MYOKO) is appointed the CO.

26 March 1943: The Battle of the Komandorski Islands:
North Pacific, off the Kamchatka Peninsula, Siberia. Rear Admiral (later Vice Admiral) Charles H. McMorris (former CO of SAN FRANCISCO, CA-38) in USS RICHMOND (CL-9) with SALT LAKE CITY (CA-25) and four destroyers engages Vice Admiral Hosogaya Boshiro's (former CO of MUTSU) Fifth Fleet's heavy cruisers NACHI (F) and MAYA, light cruisers TAMA and ABUKUMA and four destroyers escorting Convoy "D" carrying troops and supplies for the isolated garrison on Attu Island in the Aleutians. In a four-hour running gun battle, McMorris succeeds in causing the Japanese to abort their resupply mission. Disgraced, Hosogaya is relieved of command and forced to retire in July.

13 April 1943:
MUTSU departs Hashirajima for Kure. At Kure, in response to the Battle of the Komandorski Islands, she is made ready to participate in a sortie to reinforce the Aleutians. MUTSU takes aboard a full load of ammunition and supplies.

17 April 1943:
Departs Kure. Returns to Hashirajima.

18 April 1943:
Admiral Yamamoto, CINC, Combined Fleet, is killed by USAAF P-38s at Bougainville while visiting bases. This event undoubtedly delays the Aleutian sortie.

26 April 1943:
Departs Hashirajima for Tokuyama, probably to refuel.

28 April 1943:
Returns to Hashirajima.

4 May 1943:
Departs Hashirajima for gunnery practice in the Iyo Nada.

5 May 1943:
Returns to Hashirajima.

10 May 1943:
Departs Hashirajima for gunnery practice in the Iyo Nada.

11 May 1943:
Returns to Hashirajima.

12 May 1943: American Operation "Landcrab":
Rear Admiral (later Admiral) Thomas C. Kinkaid's (former CO of INDIANAPOLIS, CA-35) Task Force 16, covered by Rear Admiral Francis W. Rockwell's (former CO of THATCHER, DD-162) Task Force 51, lands the Army's 7th Division that captures Attu Island, Aleutians.

13 May 1943:
Returns to Hashirajima.

27 May 1943:
At Kure's Drydock No. 4 where her hull bottom is cleaned.

31 May 1943:
Returns to Hashirajima.

7 June 1943:
Captain Tsuruoka Nobumichi (the newly-appointed CO of FUSO) pays a call aboard MUTSU to meet with Captain Miyoshi, a classmate in Etajima's 43rd class.

8 June 1943:
MUTSU is moored at the flagship buoy midway between Hashirajima and the Suo-Oshima islands about two miles SW of Hashirajima.

At 1030 she embarks 113 cadets of No. 11 Class A Flight Reserve (Yokaren) 13th team and 40 instructors of the Tsuchiura Naval Air Group, led by Lt(jg) (Lt, posthumously) Toda Yukio (68), who are taking a familiarization tour.

Captain Tsuruoka's FUSO is moored about 1,100 yards SW of MUTSU. DesRon 11's flagship, light cruiser TATSUTA and several of the squadron's newly commissioned destroyers are moored more distantly south of Hashirajima.

1145: After lunch, MUTSU's deck crew prepares to move to mooring buoy No. 2 because NAGATO is expected to return at about 1300 from Kure. There is heavy fog and visibility is down to 500 yards. MUTSU's magazines contain a full load of ammunition including 16.1-inch Type 3 "Sanshikidan" incendiary shells designed as anti-aircraft rounds. Each shell, weighing 1,853-lbs, contains 735 submunitions. Each turret magazine contains 240 shells (120 per gun) including 50 Type 3 rounds.

1213: Suddenly, MUTSU's No. 3 turret's magazine explodes. Vice Admiral Shimizu, Commander of the First Fleet, a few miles away aboard NAGATO sees a brilliant white explosion. Shortly thereafter, he receives a plain language message from FUSO's Captain Tsuruoka. It says: "MUTSU blew up!"

MUTSU breaks in two. The 535-ft forward section collapses to starboard, sinks quickly and lies on the pagoda mast on the floor of the bay. The 147-ft stern section upends, but remains floating. FUSO immediately launches two of her Vedette boats. Later, destroyers TAMANAMI and WAKATSUKI arrive, as do boats from the cruisers TATSUTA and MOGAMI and one boat from the battleship NAGATO. An antisubmarine alert is put into effect immediately.

1430: NAGATO arrives after zigzagging through Hiroshima Bay. Later, since no submarines are sighted, the alert is cancelled, but the frequency of patrols by naval vessels and aircraft is increased in Hiroshima Bay, Iyo Nada sea and the Bungo and Kii Suido channels. NAGATO moors about 3,000 yards off FUSO's port beam and takes aboard the survivors rescued by TATSUTA. Her crew rescues 353 survivors of the 1,474 crewmembers aboard MUTSU. Only 13 of the visiting observers/instructors are among the survivors. All 39 wounded sailors are transported by TAMANAMI to a secluded hospital on Mitsugo Shima. [3]

9 June 1943:
Hashirajima: At about 0200, MUTSU's stern section sinks and comes to rest nearly upright in 130 feet of water in Hiroshima Bay at 33-58N, 132-24E.

In the morning, the first divers arrive and remain on the site for several months. FUSO serves as the base for the salvage efforts. At first, to conceal that MUTSU has sunk the divers are told that the ship they are exploring is similar to NAGATO. Then the divers are allowed to familiarize themselves on that ship.

The final list of those lost aboard MUTSU totals 1,121 men including her skipper, Captain Miyoshi and his Executive Officer, Captain Ono Koro (former XO of KIRISHIMA), both of whom are promoted to Rear Admiral, posthumously.

Tokyo: Initially the IJN's top brass suspects that the explosion was caused by a spontaneous conflagration of Type 3 "Sanshikidan" incendiary AA ammunition. Type 3 was known to contain flammable substances and there was a fire at the Sagami arsenal a few years earlier, caused by improper storage of Type 3 components. A few days after the accident, the Navy Minister, Admiral Shimada Shigetaro (former CO of HIEI) orders the Type 3 shells debarked from all IJN ships carrying them.

Hashirajima: The "M-Commission", led by 60-year-old Admiral Shiozawa Koichi (32)(former CO of FURUTAKA) is convened to conduct a formal accident investigation. Shiozawa considers all possibilities from the possibile detonation of Type 3 shells to improbable attacks by a lone American torpedo plane or an attack by either a midget or a fleet submarine. He is assisted by Rear Admiral Hoshina Zenshiro, the 22nd CO of MUTSU.

Cdr (later Captain) Yasui Yasukado (51), one of the inventors of the Type 3 shells is called in to testify. He explains that the incendiary ammunition cannot ignite or explode per se. Cdr Yasui also points out that the brown smoke observed by the survivors is not consistent with Type 3 filling, producing a white smoke when fired.

A test is conducted at Kamegakubi proving ground using a specially built mock-up of No. 3 turret. All survivors agree that they saw a brown or reddish-brown smoke prior to the explosion, consistent with a propellant fire.

Admiral Shiozawa next orders to investigate the possibility of a spontaneous propellant conflagration. The composition of propellant charges recovered from No. 3 turret magazine is analyzed and compared with that of the lots produced before and after, but no changes can be detected. Additional experiments show that under normal storage conditions the 102 DC1 propellant cannot ignite below 80 degrees Centigrade (176°F).

The "M-Commission" labors for two months before presenting their report. The commission confirms that the incendiary shells had not caused the disaster. As a result the loading of Type 3 shells on board ships is resumed. Later, the IJN revises completely their standards for the handling and storage of explosives aboard ships. A new Type 4 Mod. 3 time fuse is adopted for Type 3 AA rounds.

The investigation concludes that the explosion was "most likely caused by human interference". Some investigators think there was a ring of saboteurs, but several survivors point at a certain gunner's mate of turret No. 3, who was accused in petty theft and scheduled to appear before a naval court in Kure on 8 June. The divers manage to recover the bodies of inhabitants of crew space No. 4, where the crew of the No. 3 turret was accommodated, but the body of the suspect is not present among them.

22 July 1943:
Although the divers report that MUTSU is "bent like a broken nail", it is proposed to salvage the ship, tow it to a drydock at Kure and put her back on the line - optimistically - in three months. To convince their superiors in Kure, a dive is made with a modified 6-man Nishimura-type minisub, but it snags on a railing. All officers aboard almost suffocate before the minisub breaks free. Finally, it is decided that the battleship is beyond salvage.

A major cover-up is launched to conceal that something has happened to MUTSU. Kure Guard Force is dispatched to recover any flotsam originating from the battleship, which may reveal her identity. MUTSU's call sign is occasionally used in radio traffic to simulate her presence in remote areas of the Pacific. To further prevent rumors from spreading, many surviving sailors are later transferred to garrisons on Tarawa, Makin and Kwajalein. About 150 are sent to Saipan and almost all are killed there in 1944 during the U.S. invasion of the Marianas.

15 August 1943:
The survivors accommodated aboard FUSO are transferred to NAGATO that, with other fleet units, departs via Yashima and Yokosuka for Truk. Once the survivors arrive on Truk, they form the reserve unit of the local 41st Guard Force.

1 September 1943:
MUTSU is removed from the Navy List.

Doubts as to the cause of the disaster remain, especially by those who favor the explanation that a submarine attacked MUTSU. Several months later IJN officials question the German naval attaché in Tokyo, Vice Admiral (later Admiral/Knight's Cross) Paul Wenneker (former CO of Panzerschiff DEUTSCHLAND/LÜTZOW), about the circumstances surrounding the British Operation "Source." [4]

2 March 1944:
On that day, the USN Fleet Radio Unit, Melbourne, Australia (FRUMEL) issues the following comment:

July 1944:
The oil-starved IJN cut a hole in the bottom of MUTSU's hulk and pump out 580-tons of fuel oil for use by their ships.

31 July 1945:
Seletar Naval Base, Singapore. Cruiser TAKAO is attacked and damaged heavily by the British X-craft. For some, doubts return about the cause of the loss of MUTSU. [5]

24 June 1948:
The Nishi-Nippon Kaiji Salvage Company acquires the right to salvage ammunition and fuel from the wreck. Before the works can start, the Far Eastern Commission (FEC) issues an order preventing the salvage of items from the wreck.

20 June 1949:
A local court authorizes the Nishi-Nippon Kaiji to salvage human remains and personal belongings from the wreck. On 21 July the operations start and continue until late March 1951.

November 1952:
The salvage operations are resumed.

28 June 1953:
The bow crest is raised.

20 March 1970:
The Fukada Salvage Company acquires the salvage rights to the wreck. Salvage operations on a much larger scale start soon thereafter and continue for eight years.

23 July 1970:
Turret No. 4 is salvaged. The body of the missing gunner's mate is found inside. He is identified by two personal seals carried in the pockets of his uniform.

15-16 March 1971:
The stern section is raised.

Since then many artifacts are brought up including gun barrels, propellers, the bow section, anchors and crewmembers' personal belongings.

February 1972:
The bow section is lifted in a two-stage operation in using a 1,500-ton floating crane.

November 1972:
The MUTSU Memorial Museum opens in Towa-cho on Yashiro Jima Island.

1978:
Salvage operations cease.

27 April 1994:
The museum moves into a new building.

1995:
According to a statement by the MUTSU Memorial Museum, no further salvage operations are planned.

9 April 2007:
JMSDF survey vessel KURUSHIMA compiles the multibeam image of the wreck of MUTSU.

An article in "Warship 2009" suggests that the explosion might have been a result of an unnoticed fire in the area adjacent to the No. 3 magazine. Considering the number of people who were present belowdecks prior to the explosion it seems somewhat far-fetched.

A recent Japanese theory (not supported by naval experts) suggests that the explosion was triggered by the detonation of unexploded depth charges on the seabed that were dropped during a naval exercise by the destroyer USHIO. Another theory put forward by Tashiro Gunjuro, a secondary battery gunner from NAGATO in "Gakken Pictorial" Vol. 15 (1997), suggests that the explosion was in fact caused by improperly manufactured Type 3 ammunition as a result of electrostatic discharge of its incendiary filling.

To date the best source on that disaster remains the book "MUTSU Exploded" (1970) written by the naval historian Yoshimura Akira, who interviewed most of the survivors from that vessel. In their opinion the gunner's mate from turret No. 3 intended to escape from the ship while creating a magazine fire as a diversion. He must have disabled the temperature sensors prior to setting fire to several propellant charges, extracted from their fireproof cases, but evidently failed to exit the magazine before an explosion occurred.