Nagato-class battleship
Nagato at sea
| |
Class overview | |
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Name | Nagato class |
Builders | |
Operators | Imperial Japanese Navy |
Preceded by | Ise class |
Succeeded by |
|
Built | 1917–1921 |
In service | 1920–1945 |
Completed | 2 |
Lost | 1 |
General characteristics (as built) | |
Type | Dreadnought battleship |
Displacement |
|
Length | 215.8 m (708 ft) ( o/a ) |
Beam | 29.02 m (95 ft 3 in) |
Draft | 9.08 m (29 ft 9 in) |
Installed power |
|
Propulsion | 4 shafts; 4 × geared steam turbines |
Speed | 26.5 knots (49.1 km/h; 30.5 mph) |
Range | 5,500 nmi (10,200 km; 6,300 mi) at 16 knots (30 km/h; 18 mph) |
Complement | 1,333 |
Armament |
|
Armor |
|
General characteristics (Nagato, 1944) | |
Displacement |
|
Length | 224.94 m (738 ft 0 in) ( o/a ) |
Beam | 34.6 m (113 ft 6 in) |
Draft | 9.49 m (31 ft 2 in) |
Installed power |
|
Speed | 25 knots (46 km/h; 29 mph) |
Range | 8,650 nmi (16,020 km; 9,950 mi) at 16 knots (30 km/h; 18 mph) |
Complement | 1,734 |
Sensors and processing systems |
|
Armament |
|
Armor | |
Aircraft carried | 3 × floatplanes |
Aviation facilities | 1 × catapult |
The Nagato-class battleships (長門型戦艦, Nagato-gata senkan) were a pair of
The sisters participated in the Battle of Midway in June 1942, although they did not see any combat. Mutsu saw more active service than her sister because she was not a flagship and participated in the Battle of the Eastern Solomons in August before returning to Japan in early 1943. One of Mutsu's aft magazines detonated in June, killing 1,121 crew and visitors and destroying the ship. The IJN conducted a perfunctory investigation into the cause of her loss and concluded that it was the work of a disgruntled crewmember. They dispersed the survivors in an attempt to conceal the sinking to keep up morale in Japan. Much of the wreck was salvaged after the war and many artifacts and relics are on display in Japan.
Nagato spent most of the first two years of the war training in home waters. She was transferred to Truk in mid-1943, but did not see any combat until the Battle of the Philippine Sea in mid-1944 when she was attacked by American aircraft. Nagato did not fire her main armament against enemy vessels until the Battle of Leyte Gulf in October 1944. She was lightly damaged during the battle and returned to Japan the following month for repairs. The IJN was running out of fuel by this time and decided not to fully repair her. Nagato was converted into a floating anti-aircraft platform and assigned to coastal defense duties. After the war, the ship was a target for U.S. nuclear weapon tests during Operation Crossroads in mid-1946. She survived the first test with little damage, but was sunk by the second test.
Background
The IJN considered a battle fleet of eight modern battleships and eight modern
Design
Allocated project number A-102, the Nagato class was designed before Commander Yuzuru Hiraga was reassigned to the Navy Technical Department (NTD) responsible for ship design, although Hiraga is often credited with the design of these ships.[Note 1] In contrast to earlier designs, the Nagato class used the American "all or nothing" armor scheme that maximized the armor thickness protecting the core of the ship by eliminating armor elsewhere.[5] The design had two armored decks of medium thickness rather than the single thicker deck used formerly. The ships also used a new type of underwater protection system that successfully resisted penetration by 200-kilogram (440 lb) torpedo warheads in full-scale trials. It consisted of a deep water-tight compartment adjacent to the hull, backed by a thick torpedo bulkhead that connected to the side and deck armor plates, with a deep fuel oil tank behind it.[6]
Although the
On 12 June 1917, well before Mutsu was
Description
The ships had a length of 201.17 meters (660 ft)
The Nagato class was equipped with a unique heptapodal (seven-legged) mast designed to maximize rigidity for range-finding purposes and survivability under shellfire. It consisted of a thick vertical leg in the center surrounded by six outer legs. The central leg was large enough to accommodate an electric
In 1927, Mutsu's bow was remodeled to reduce the amount of spray produced when steaming into a
Propulsion
The ships were equipped with four Gihon geared
The ships had a stowage capacity of 1,600 long tons (1,626 t) of coal and 3,400 long tons (3,455 t) of oil,[10] giving them a range of 5,500 nautical miles (10,200 km; 6,300 mi) at a speed of 16 knots (30 km/h; 18 mph). Nagato exceeded her designed speed of 26.5 knots (49.1 km/h; 30.5 mph) during her sea trials, reaching 26.7 knots (49.4 km/h; 30.7 mph) at 85,500 shp (63,800 kW) and Mutsu reached the same speed with 87,500 shp (65,200 kW).[11] The US Navy did not learn their actual speed capability until about 1937; previously it had believed that the ships were capable of only 23 knots (43 km/h; 26 mph).[5]
During refits in 1923–25, the fore funnel was rebuilt in a serpentine shape in an unsuccessful effort to prevent smoke interference with the
Armament
The
By World War II, the guns used Type 91
The ships' secondary armament of twenty 50-caliber
Around 1926, the four above-water torpedo tubes were removed and the ships received three additional 76-millimeter AA guns that were situated around the base of the foremast.
When the ships were reconstructed in 1934–36, the remaining torpedo tubes and the two forward 14-centimeter guns were removed from the hull. All of the remaining 14-centimeter guns had their elevation increased to +35 degrees which increased their range to 20,000 meters (22,000 yd). An unknown number of license-built
The 2-pounders were replaced in 1939 by 20 license-built
Armor
The Nagato-class ships'
The main deck armor consisted of three layers of high-tensile steel (HTS) 69 mm (2.7 in) thick that connected to the top of the upper strake of side armor. The flat portion of the lower deck had one layer of Ducol steel 25 mm thick with two layers of HTS of equal thickness above it. About 3 meters (9 ft 10 in) from the side of the hull, this deck, now composed of three layers of HTS, totaling 75 mm (3 in) in thickness, sloped downwards where it met a short horizontal armored (three layers of HTS with a total thickness of 66 mm (3 in)) deck that connected to the main armored belt and the torpedo bulkhead. This was also made up of three 25 mm layers of HTS[Note 4] and curved up and outwards to meet the short horizontal armored deck. It enclosed a water-tight compartment that was 3.05 meters (10 ft 0 in) from the side of the ship. It was backed by fuel oil tanks 3.13 meters (10 ft 3 in) deep.[39] The outermost void was designed to allow the explosive force of a torpedo's warhead to dissipate as much as possible while the oil tank was supposed to stop any fragments from penetrating the innermost bulkhead protecting the ship's vital areas.[40]
The new 41 cm turrets installed during their reconstruction were more heavily armored than the original ones. Face armor was increased to 460 mm (18 in), the sides to 280 mm (11 in), and the roof to 230–250 mm (9–10 in).[41] The armor over the machinery and magazines was increased by 38 mm (1.5 in) on the upper deck and 25 mm on the upper armored deck.[17] The torpedo bulges added at the same time were 13.5 meters (44 ft 3 in) high and 2.84 meters (9 ft 4 in) deep. They were divided into four compartments, the lower two of which were filled with oil and the others remained empty.[42] These additions increased the weight of each ship's armor to 13,032 metric tons (12,826 long tons),[18] 32.6 percent of their displacement.[17] In early 1941, as a preparation for war, the uppermost compartment of the bulges was filled with sealed steel crushing tubes[13] and the barbette armor of both ships was reinforced with 100 mm armor plates above the main deck and 215 mm (8.5 in) plates below it.[43]
Fire control and sensors
The Nagato-class ships were fitted with a 10-meter (32 ft 10 in)
They were initially fitted with a Type 13 fire-control system derived from Vickers equipment received during
As far as is known, no
Aircraft
Nagato was briefly fitted with an 18-meter (59 ft 1 in)[46] aircraft flying-off platform on No. 2 turret in August 1925. Yokosuka Ro-go Ko-gata and Heinkel HD 25 floatplanes were tested from it before it was removed early the following year.[13] An additional boom was added to the mainmasts of both ships in 1926 to handle the Yokosuka E1Y then assigned to them.[26] A Hansa-Brandenburg W.33 floatplane was tested aboard Nagato that same year.[13] A catapult was fitted between the mainmast and No. 3 turret[47] in mid-1933,[13] a collapsible crane was installed in a portside sponson, and the ships were equipped to operate two or three floatplanes, although no hangar was provided. The sisters began to operate Nakajima E4N2 biplanes until they were replaced by Nakajima E8N2 biplanes in 1938. A more powerful catapult was installed in November 1938 to handle heavier aircraft like the one Kawanishi E7K that was added in 1939–40. Mitsubishi F1M biplanes replaced the E8Ns on 11 February 1943.[48]
Ships
Name | Kanji | Builder[10] | Laid down[10]
|
Launched[10] | Completed[10] | Fate |
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Nagato | 長門 | Kure Naval Arsenal | 28 August 1917 | 9 November 1919 | 25 November 1920 | Sunk during Operation Crossroads, 29/30 July 1946[49] |
Mutsu | 陸奥 | Yokosuka Naval Arsenal | 1 June 1918 | 31 May 1920 | 24 October 1921 | Sunk by internal explosion, 8 June 1943[36] |
Construction and service
While Mutsu was still fitting out, the American government decided to call a conference in Washington, D.C. to forestall the massively expensive naval arms race between the United States, the United Kingdom and the Empire of Japan that was developing. The Washington Naval Conference convened on 12 November, and the Americans proposed to scrap virtually every capital ship under construction or fitting out among the participating nations. Mutsu was specifically listed among those to be scrapped even though she had been commissioned a few weeks earlier. This was unacceptable to the Japanese delegation and they agreed to a compromise that allowed them to keep Mutsu in exchange for scrapping the obsolete dreadnought Settsu and a similar arrangement for several American Colorado-class dreadnoughts that were fitting out.[50]
Upon commissioning, the
The ships were reconstructed from late 1933 to mid-1936. In August 1937, the sisters transported 3,749 men of the 11th Infantry Division to Shanghai during the Second Sino-Japanese War.[13][51] Their floatplanes bombed targets in Shanghai on 24 August before they returned to Sasebo the following day.[52] Nagato became a training ship on 1 December 1937 until she again became the flagship of the Combined Fleet on 15 December 1938. The ship participated in an Imperial Fleet Review on 11 October 1940.[13] The sisters were refitted in 1941 in preparation for war, which included the fitting of external degaussing coils and additional armor for their barbettes.[13][51]
World War II
Admiral Isoroku Yamamoto issued the code phrase "Niitaka yama nobore" (Climb
In June 1942, Mutsu and Nagato were assigned to the Main Body of the 1st Fleet during the Battle of Midway, together with Yamato, Hōshō, the light cruiser Sendai and nine destroyers.[53][54] Following the loss of all four fleet carriers of the "Kido Butai" on 4 June, Yamamoto attempted to lure the American forces west to within range of the Japanese air groups at Wake Island, and into a night engagement with his surface forces, but the American forces withdrew and Mutsu saw no action. After rendezvousing with the remnants of the Striking Force on 6 June, over half of the survivors from the sunken aircraft carriers of the 1st Air Fleet were transferred to Mutsu and Nagato.[55] They arrived at Hashirajima on 14 June.[51]
On 14 July, both ships were reassigned to Battleship Division 2 and Nagato became the flagship of the 1st Fleet. She remained in Japanese waters training until August 1942.
During the Battle of the Eastern Solomons on 27 August, Mutsu, assigned to the Support Force,[56] fired four shells at enemy reconnaissance aircraft during what was her first, and only, action of the war.[57] On 7 January 1943, Mutsu returned to Japan together with the carrier Zuikaku, the heavy cruiser Suzuya and four destroyers. The ship prepared to sortie on 13 April to reinforce the Japanese garrisons in the Aleutian Islands in response to the Battle of the Komandorski Islands, but the operation was cancelled the next day and Mutsu resumed training.[51]
Mutsu's loss
On 8 June 1943, Mutsu was moored at Hashirajima when the magazine of her No. 3 turret exploded at 12:13, cutting the ship in half. The forward section
The IJN convened a commission three days after the sinking to investigate the loss. It issued its preliminary conclusions on 25 June, well before the investigation of the wreck was completed, and decided that the explosion was the result of a disgruntled seaman. The commission failed to consider the possibility of fire, which historian Mike Williams considers to be a possible cause, as a number of observers noted smoke coming from the vicinity of No. 3 turret. The truth, however, will never be known.[59]
Nagato
Nagato transferred to
Battleship Division 1 rendezvoused with Ozawa's main force on 16 June near the Mariana Islands, and Nagato escorted three aircraft carriers during the Battle of the Philippine Sea. She was only lightly engaged during the battle, was not damaged, and suffered no casualties.[13] After the battle, the ship returned to Japan where she was refitted with additional radars and light AA guns. Nagato loaded a regiment of the 28th Infantry Division and delivered them at Okinawa on 11 July before continuing on to Lingga.[60]
In October 1944, the ship took part in "Operation Sho-1", an attack on the
The next morning, the 1st Diversion Force attacked the American forces supporting the invasion in the
The ship returned to Japan for repairs in mid-November. Lack of fuel and materials meant that she could not be brought back into service and she was turned into a
After the war
Nagato was selected to participate as a target ship in
Operation Crossroads began with the first blast (Test Able), an
Mutsu's wreck in Japan was treated differently. In 1970, salvage operations began that lasted until 1978 and recovered about 75% of the ship. The salvagers recovered bodies of 849 crewmen killed during the explosion. In 1995, the Mutsu Memorial Museum declared that no further salvage operations were planned. The only significant portion of the ship that remains is a 35-meter (114 ft 10 in) long section running from the bridge structure forward to the vicinity of No. 1 turret. The highest portion of the ship is 12 meters (39 ft 4 in) below the surface. Many, but not all, artifacts are displayed at the Mutsu Memorial Museum in Tōwa-Cho. Since 1963, a memorial service has been held there every year on 8 June in honor of the crew.[64]
Notes
- ^ Nagato was ordered on 12 May 1916 and Hiraga returned to the NTD three days later.[4]
- QF 12-pounder guns. While the Japanese designated them as 8 cm, their actual caliber was 76.2 millimeters.[24]
- ^ Skwiot says two single mounts in 1932–34 and another pair, mounted near the aft funnel, were added in 1934.[29]
- ^ This was intended to be a single plate of New Vickers non-cemented armor of equal thickness, but it could not be formed into the required shape.[38]
- Hawaiian Standard Time, so in Japan, the attack on Pearl Harborhappened on 8 December.
- ^ No cruisers were present, only destroyers and destroyer escorts.[13]
Footnotes
- ^ Evans & Peattie, p. 150
- ^ Stille, p. 7
- ^ Evans & Peattie, pp. 160, 166–167
- ^ Lengerer, footnote 3
- ^ a b c Gardiner & Gray, p. 231
- ^ Lengerer, pp. 4–5; Skwiot 2008, pp. 3, 8
- ^ Lengerer, p. 4
- ^ Lengerer, pp. 3, 6–7
- ^ Skwiot 2008, p. 4
- ^ a b c d e f g h Whitley, p. 200
- ^ a b c Jentschura, Jung & Mickel, p. 28
- ^ Stille, p. 34
- ^ a b c d e f g h i j k l m n o p q r s t u v w Hackett, Kingsepp & Ahlberg, Nagato
- ^ Skwiot 2008, pp. 6, 9–10, 34, 71–72
- ^ Skwiot 2008, pp. 43–44
- ^ Skwiot 2008, pp. 73, 76–77
- ^ a b c Stille, p. 32
- ^ a b Skwiot 2008, pp. 43, 78
- ^ Skwiot 2008, p. 19
- ^ a b Friedman, p. 269
- ^ Campbell, pp. 175, 181–182
- ^ Skwiot 2008, pp. 24, 73
- ^ Campbell, p. 190
- ^ a b Campbell, p. 198
- ^ Skwiot 2008, p. 31
- ^ a b Skwiot 2008, p. 70
- ^ Whitley, p. 202
- ^ Campbell, pp. 192–193
- ^ Skwiot 2008, pp. 26, 72
- ^ Campbell, p. 74
- ^ Skwiot 2008, pp. 33, 72–73
- ^ Campbell, p. 202
- ^ Hackett, Kingsepp & Ahlberg, Mutsu and Nagato
- ^ Stille, p. 11
- ^ Campbell, p. 200
- ^ a b c Williams, p. 129
- ^ Skwiot 2008, p. 80
- ^ Lengerer, footnote 8
- ^ Skwiot 2008, pp. 3, 10–11
- ^ Lengerer, pp. 4–5
- ^ Campbell, p. 182
- ^ Skwiot 2008, pp. 9, 73
- ^ Chesneau, p. 172
- ^ Skwiot 2008, pp. 34, 72
- ^ Skwiot 2008, pp. 33–37
- ^ Skwiot 2008, p. 47
- ^ Skwiot 2008, p. 57
- ^ Skwiot 2008, pp. 54, 57
- ^ a b c d Tully
- ^ Skwiot 2008, pp. 17–19, 21
- ^ a b c d e f Hackett, Kingsepp & Ahlberg, Mutsu
- ^ Skwiot 2007, pp. 36, 81
- ^ Rohwer, pp. 168–169
- ^ Parshall & Tully, p. 453
- ^ Parshall & Tully, pp. 382–383
- ^ Rohwer, p. 190
- ^ Williams, p. 125
- ^ Williams, pp. 132–133
- ^ Williams, pp. 135, 142
- ^ Skwiot 2007, p. 46
- ^ Skwiot 2007, p. 51
- ^ "Bikini Atoll Dive Tourism Information". Bikini Atoll Divers. Retrieved 8 January 2014.
- ^ Ecott, Tim (3 March 2007). "World's Best Wreck Diving". The Times. London. Retrieved 11 September 2009.(subscription required)
- ^ Williams, pp. 138–141
References
- Campbell, John (1985). Naval Weapons of World War II. Annapolis, Maryland: Naval Institute Press. ISBN 0-87021-459-4.
- Chesneau, Roger, ed. (1980). Conway's All the World's Fighting Ships 1922–1946. Greenwich, UK: Conway Maritime Press. ISBN 0-85177-146-7.
- Evans, David C. & ISBN 0-87021-192-7.
- Friedman, Norman (2011). Naval Weapons of World War One. Barnsley, South Yorkshire, UK: Seaforth. ISBN 978-1-84832-100-7.
- Gardiner, Robert & Gray, Randal, eds. (1985). Conway's All the World's Fighting Ships 1906–1921. Annapolis, Maryland: Naval Institute Press. ISBN 0-87021-907-3.
- Hackett, Bob; Kingsepp, Sander & Ahlberg, Lars (2009). "IJN Mutsu: Tabular Record of Movement". Combinedfleet.com. Retrieved 15 May 2013.
- Hackett, Bob; Kingsepp, Sander & Ahlberg, Lars (2009). "IJN Nagato: Tabular Record of Movement". Combinedfleet.com. Retrieved 15 May 2013.
- Jentschura, Hansgeorg; Jung, Dieter & Mickel, Peter (1977). Warships of the Imperial Japanese Navy, 1869–1945. Annapolis, Maryland: United States Naval Institute. ISBN 0-87021-893-X.
- Lengerer, Hans (June 2010). Ahlberg, Lars (ed.). "Battleships of the Kaga Class and the So-called Tosa Experiments". Contributions to the History of Imperial Japanese Warships (Special Paper I): 1–26.
- Parshall, Jonathan & Tully, Anthony (2007). Shattered Sword: The Untold Story of the Battle of Midway. Washington, D. C.: Potomac Books. ISBN 978-1-57488-924-6.
- Rohwer, Jurgen (2005). Chronology of the War at Sea, 1939–1945: The Naval History of World War Two. Annapolis, Maryland: Naval Institute Press. ISBN 1-59114-119-2.
- Silverstone, Paul H. (1984). Directory of the World's Capital Ships. New York: Hippocrene Books. ISBN 0-88254-979-0.
- Skwiot, Miroslaw (2007). Nagato Mutsu, Part I. Encyklopedua Okretów Wojennych. Vol. 51. Gdansk, Poland: AJ-Press. ISBN 978-83-7237-184-3.
- Skwiot, Miroslaw (2008). Nagato Mutsu, Part II. Encyklopedia Okretów Wojennych. Vol. 52. Gdansk, Poland: AJ-Press. ISBN 978-83-7237-202-4.
- Stille, Mark (2008). Imperial Japanese Navy Battleships 1941–45. New Vanguard. Vol. 146. Botley, Oxford, UK: Osprey Publishing. ISBN 978-1-84603-280-6.
- Tully, A.P. (2003). "Nagato's Last Year: July 1945 – July 1946". Mysteries/Untold Sagas of the Imperial Japanese Navy. Combinedfleet.com. Retrieved 26 May 2013.
- Whitley, M. J. (1998). Battleships of World War II. Annapolis, Maryland: Naval Institute Press. ISBN 1-55750-184-X.
- Williams, Mike (2009). "Mutsu – An Exploration of the Circumstances Surrounding her Loss". In Jordan, John (ed.). Warship 2009. London: Conway. pp. 125–142. ISBN 978-1-84486-089-0.
External links