Nagato class battleship, IJN Mutsu - A tragedy and mystery

de_Radio_Demon · September 23, 2023, 7:34pm

Would you like to see IJN Mutsu added to the game?

Yes
Maybe
Unsure
No

0 voters

What refit/configuration would you like to see Mutsu added in?

As built
1933 Refit
1936 Modernization and reconstruction
1937 Configuration *
1938 Refit
1941 Configuration *
1943 Configuration *
Unsure
I said no to the first question

0 voters

Notes for poll -

Any option listed under question 2 with a star * is not a refit but saw a change in the floatplanes used so armament is relevant to the refit listed before that.
Not all refits are covered, only those that resulted in modification to the ships armament or any major modernization, more minor refits that saw structural changes of sorts that wouldn’t affect the ship in-game are those that are not included.
As stated under the specifications for the floatplanes the 1937 complement of floatplanes is not confirmed but is believed to have been made up by said number of aircraft then, so their is no guarantee the ship would be added with that complement of aircraft.

Nagato class battleship, IJN Mutsu - A tragedy and mystery

Background
IJN Mutsu was the second ship of the Nagato class battleships which began construction in the final year of the First World War and would enter service in the 1920’s. The two ships represented for years as the most powerful of all Japanese battleships up until 1940’s with the Yamato class succeeding them as a result of the Washington Naval treaty which limited the amount of ships in different areas for the major naval powers.

In terms of armament the Mutsu would be armed with as built with a main armament of 8 41 cm/45 (16 inch) 3rd year type guns in 4 twin mounts, a secondary armament of 20 14 cm/50 (5.5 inch) 3rd Year Type guns in casemate mounts, a tertiary AA armament of 4 x 8 cm/40 (3 inch) 3rd Year Type guns, and 8 533mm torpedo tubes. During the ships career the class would be refitted as they replaced the 3 inch guns with 8 12.7 cm/40 (5 inch) Type 89 guns in 4 twin mounts and 2 40mm/62 Type 91 AA guns, and in the late 1930’s the ships would undergo a major modernization which improved the 16 inch gun turrets, reduced the secondary armament reduced to 18 guns, and the removal of the 40mm guns and replaced by 20 25mm Type 96 AA guns in 10 twin mounts. Along with the modernization the torpedo tubes were removed, the superstructure was rebuilt, hull lengthened, new boilers installed, reduction in the number of funnels, and the installation of a catapult and floatplanes.

History

Spoiler

The Nagato class itself like most Japanese battleships were built under the eight eight fleet plan which in its original iteration called for 8 modern pre dreadnoughts and 8 modern armored cruisers however over time with the escalation of ship designs became 8 dreadnought type battleships and 8 battlecruisers. By 1915 the Japanese navy were half way to achieving their goal of the eight eight fleet with at the time the current iteration being made up by the 2 Fuso and 2 Ise class battleships and the 4 Kongo class ships and were seeking to get the 4 remaining battleships, however in 1916 the Japanese diet would only approve 1 battleship which later became the Nagato and 2 battlecruisers.

Despite expectations being cut short the government’s stance would change with the announcement by the United States of 10 new battleships and 6 battlecruisers, this prompted the Japanese government to respond by approving 3 more battleships in 1917 which would result in the Mutsu and the orders of the 2 Kaga class battleships. Not only did the announcement of the expansion of the US see further ships ordered but the eight eight plan revised as it no longer included the Fuso and Ise classes and would lead to further designs to be ordered with the Kii class battleships, the Amagi class battlecruisers, and the never to be realized No. 13 class.

In the end however out of the new battleships only the two Nagato’s would come to pass with the signing of the Washington naval treaty which placed limitations of battleship designs and numbers. The result of the treaty was the cancellation of further designs as the Kii class was broken up on the slipway while two of Amagi class were to likewise be scrapped on the slipway while the other two would be converted into aircraft carriers. Due the great Kanto earthquake the Amagi would be scrapped as well, also as a result one of the Kaga class would undergo conversion instead and the other would be used to test the design’s armor scheme.

Mutsu would be launched on May 31st, 1920 which also was attended by one future emperor of Japan LtCdr/Crown Prince Hirohito along with his mother, and the ship would be commissioned on October 24th, 1921. Mutsu’s career as a whole was almost cut short as during the negotiations for the Washington naval treaty in 1922 the ship was listed as one of the ships to be scrapped. Unsurprisingly the Japanese delegation and the government very much opposed the idea of having the Mutsu scrapped as they were not only heavily invested in the ship by that point but part of the funding for the ship came from public donations, and the Japanese argued the ship had already been commissioned by September 10th of the previous year and had steamed 2,500 nautical miles. In the end the Japanese were able save the Mutsu as in exchange the were required to scrap the obsolete battleship Settsu and the total allotted tonnage for ships with a caliber of 16 inch guns had increased which would allow Japan to keep Mutsu, the United States to retain a third Colorado class battleship, and the British would likewise be able to acquire an additional ship which was later the two Nelson class battleships plus the Hood.

In April of 1922 Mutsu would host Edward, Prince of Wales, and his aide-de-camp and second cousin, Lieutenant Louis Mountbatten, on the prince’s visit to Japan. In 1923 the Mutsu along with Nagato would be loaded with food, provisions and medical supplies and would assist in relief efforts after the great Kanto earthquake and in November would undergo a refit. In 1924 Mutsu would suffer a collision with the Nagato after the CO of Nagato mistook the drift of the ship, due to last minute maneuvers no lives were lost however the Nagato suffered minor damage to her hull plating and lost an anchor. Mutsu herself would undergo a number of other refits during the 1920’s during which in 1927 she served as the flagship for emperor Hirohito during a naval fleet review.

During the 1930’s she would be involved in towing back the light cruiser Abukuma after a collision in the night with the light cruiser Kitakami which saw the cruiser lose her bow. The ship would continue to undergo various refits and would also undergo a major modernization and reconstruction, and with Japan’s invasion of China the Mutsu along with Nagato would be involved in operations against China including aerial attacks with the floatplanes that had been installed during the modernization efforts. After retiring to Japan Mutsu would undergo a followup refit to her modernization. With the ship undergoing maintenance a few days prior Mutsu along with BatDiv 1 sorties from Hashirajima to the Bonin Islands with the First Fleet’s BatDiv 2 as Japan began to enact its entry into the second world war.

Despite being at war Mutsu would see limited action and would find herself taking part in various training operations acting as a target tug for the Yamato who would later join BatDiv 1. Mutsu would be present for the battle of Midway but was apart of the main force that along with Yamato was not involved in any combat however later took on survivors of the Akagi from Japanese destroyers, and in late August of 1942 she would fire her first and only shots of anger as her AA gunners fired on American recon aircraft.

Loss of Mutsu

Mutsu’s career in 1943 would not result in much as she ended up spending most of it closer to home in Japan until June 8th. On that day the Mutsu was at anchor between Hashirajima and the Suo-Oshima islands about two miles SW of Hashirajima, during 10:30 in the morning the ship had a 113 cadets of No. 11 Class A Flight Reserve (Yokaren) 13th team and 40 instructors of the Tsuchiura Naval Air Group all visiting the ship in a familiarization tour. At the same time the Fuso was moored about 1,100 yards south west of MUTSU. DesRon 11’s flagship, light cruiser Tatsuta and several of the squadron’s newly commissioned destroyers were moored more distantly south of Hashirajima. After the crew had lunch at 11:45 the crew began to prepare to move to mooring buoy No. 2 as it was expected the Nagato would return from Kure by 1:00 pm. During this time there was a heavy fog in the area which reduced visibility down to 500 yards, and at 12:13 pm the Mutsu suffered a major explosion from No.3 turret. The blast of the explosion was visible enough to be seen through the fog from the Nagato which was a few miles away, the Vice Admiral Shimizu, the Commander of the First Fleet after witnessing the flash of light receives the plain message from the Fuso’s captain reporting that Mutsu blew up.

The resulting explosion despite originating from the rear of the ship, the 535 ft forward section collapses of the ship to starboard and sinks quickly and lies on the pagoda mast on the floor of the bay. The 147-ft stern section remains upends, but remains floating, and following the explosion Fuso immediately launches two of her Vedette boats. Later the destroyers Tamanami and Wakatsuki arrive, as do boats from the cruisers Tatsuta and Mogami and one boat from the Nagato.

Due to the sudden nature of the event and with obviously little information an anti submarine alert is put into effect immediately, however this is later canceled after none were sighted. By 14:30 after entering into zigzag maneuvers the Nagato showed up and orders were given to increase patrols in the area due to the possibility of their being a submarine. Of the 1,474 onboard at the time only 353 survived of which only 13 were of the visiting observers/instructors, and by 2:00 am the following day the stern of the ship sank upright.

Despite the scale of the incident the Japanese choose to cover up the incident and during the original salvage operations which were based from the Fuso. In order to cover up the incident the divers were told that the ship was one similar to the layout of Nagato and had them familiarize with the Nagato. The dives themselves would confirm the total amount of lives lost with a total of 1,121 died from the incident. At first the initial investigation gave the idea the ship suffered an internal explosion as the ship was carrying a large amount of Type 3 “Sanshikidan” incendiary AA ammunition however later investigations would propose other causes as all survivors reported seeing brown/red smoke from turret No.3 which was inconsistent from the smoke given off by the Type 3 round which emitted a white smoke. The final conclusion of the investigation was that it was the result of sabotage as it was suspected one of the gunners assigned to the turret No.4 caused it as they were due in court after being accused of theft however the divers couldn’t conclude the theory as they were unable to find the body.

Despite the catastrophic explosion the divers very optimistically proposed that the ship can be refloated and brought back into service in 3 months, though one could imagine that this was under the impression they weren’t looking at a battleship. At first the efforts to hid the sinking from the allies did work however with survivors being reassigned to other ships and fighting on different islands being captured Japanese POWs began to confirm the sinking of the Mutsu, and with supplies running out the Japanese cut a hole into the ship to take the ships fuel due to the shortages.

Post war

After the war salvage operations would continue on Mutsu would last for years and would see various parts of the ship raised including the bow crest in 1953 and turret No.4 in 1970, the latter of which also located the body of the missing gunner who was suspected of committing sabotage. In 1972 operations took place to raise the ship’s bow in two stages and later that year the Mutsu Memorial Museum opened in Towa-cho on Yashiro Jima Island.

In 1978 all salvage operations would cease on the Mutsu with no further work intended as stated by the Mutsu Memorial Museum in 1995. Due to the nature of the ships sinking a variety of artifacts still survive from the ship that now are present at different museums, including a few of the ships main guns and part of the bow, rudder, and other parts of the ship, including even a fully restored turret No. 4 which an be found at the Imperial Japanese Naval Academy at Etajima, however this turret was the original No.4 turret that was removed during the major modernization and rebuild of the ship rather than salvaged from the ship as it is sometimes labeled as.

Specifications
Displacement -
As built
32,720 tons(standard)
38,500 tons (fully loaded)
Post modernization/Rebuild
39,130 tons (standard)
42,850 tons (fully loaded)

Length -
As built
215.8 m (708 ft) (o/a)
Post modernization/Rebuild
224.94 m (738 ft 0 in) (o/a)

Beam -
As built
28.96 m (95 ft)
Post modernization/Rebuild
34.6 m (113 ft 6 in)

Draft -
As built
9.10 m
Post modernization/Rebuild
9.49 m

Installed power -
As built
21 × Kampon water-tube boilers
80,000 shp
Post modernization/Rebuild
10 x Kampon water-tube boilers
82,000 shp

Propulsion -
As built
4 shafts; 4 × Gihon geared steam turbines
Post modernization/Rebuild
4 shafts; 4 x Kampon-Parsons geared steam turbines

Speed -
As built
26.5 knots (49.1 km/h; 30.5 mph)
Post modernization/Rebuild
25 knots (46 km/h; 29 mph)

Complement -
1,333 (1921)
1,368 (1936)
1,475 (1942)

Armament -
As built
Main armament -
8 x 41cm/45 (16 inch) 3rd Year type guns (4 x 2)
Secondary armament -
20 x 14 cm/50 (5.5 inch) 3rd Year type guns (20 x 1)
AA armament -
4 x 3 inch/40 (76mm) 3rd Year type guns (4 x 1)
Torpedo tubes -
8 x 53.3 cm (21 inch) Torpedo tubes

1933 Refit
Main armament -
8 x 41cm/45 (16 inch) 3rd Year type guns (4 x 2)
Secondary armament -
20 x 14 cm/50 (5.5 inch) 3rd Year type guns (20 x 1)
AA armament -
8 x 12.7 cm/40 (5 inch) Type 89 guns (4 x 2)
2 x 40 mm/62 (1.575 inch) “BI” Type 91 guns (2 x 1)
Torpedo tubes -
8 x 53.3 cm (21 inch) Torpedo tubes

1936 Modernization & reconstruction
Main armament -
8 x 41cm/45 (16 inch) 3rd Year type guns (4 x 2)
-New turrets installed with improved elevation to 43 degrees
Secondary armament -
18 x 14 cm/50 (5.5 inch) 3rd Year type guns (18 x 1)
-Gun elevation of mounts is increased to 35 degrees
AA armament -
8 x 12.7 cm/40 (5 inch) Type 89 guns (4 x 2)
2 x 40 mm/62 “BI” Type 91 guns (2 x 1)

1938 Refit
Main armament -
8 x 41cm/45 (16 inch) 3rd Year type guns (4 x 2)
Secondary armament -
18 x 14 cm/50 (5.5 inch) 3rd Year type guns (18 x 1)
AA armament -
8 x 12.7 cm/40 (5 inch) Type 89 guns (4 x 2)
20 x 25mm/62 Type 96 AA guns (10 x 2)

Armor
As built
belt: 305mm - 102mm
bulkheads: 330mm - 254mm
deck: 51mm + 70mm
barbettes: 305mm - 229mm
turrets: 356mm - 127mm
casemates: 152mm - 19mm
CT: 356mm - 102mm

1936 Post modernization/Rebuild
belt: 305mm - 102mm
bulkheads: 330mm - 254mm
deck: 127mm + 70mm
barbettes: 457mm - 356mm
turrets: 457mm - 127mm
casemates: 152mm - 19mm
CT: 356mm - 102mm

Aviation facilities (1936 onwards)
1 x Catapult

Aircraft carried
1936 Refit
3 x Nakajima E4N2 No. 2 Model 2 floatplanes

1937 (Not confirmed but believed to have occurred according to one source)
3 x Nakajima E8N Type 95 floatplanes

1938 Refit
1 x Kawanishi E7K2 Type 94 floatplane
3 x Nakajima E8N2 Type 95 floatplanes

1941
2 x Nakajima E8N2 Type 95 floatplanes

1943
2 x Mitsubishi F1M2 floatplanes

More images

Spoiler