Fusō-class battleship

The were a pair of dreadnought battleships built for the Imperial Japanese Navy (IJN) before World War I and completed during it. Both patrolled briefly off the coast of China before being placed in reserve at the war's end. In 1922 became the first battleship in the IJN to successfully launch aircraft.

During the 1930s, both ships underwent a series of modernizations and reconstructions. underwent her modernization in two phases (1930–33, 1937–41), while ''Yamashiro'' was reconstructed from 1930 to 1935. The modernization increased their armor, replaced and upgraded their machinery, and rebuilt their superstructures into the distinctive pagoda mast style. Despite the expensive reconstructions, both vessels were considered obsolescent by the eve of World War II, and neither saw significant action in the early years of the war. ''Fusō'' served as a troop transport in 1943, while ''Yamashiro'' was relegated to training duty in the Inland Sea. Both underwent upgrades to their anti-aircraft suite in 1944 before transferring to Singapore in August 1944.

''Fusō'' and ''Yamashiro'' were the only two Japanese battleships at the Battle of Surigao Strait, the southernmost action of the Battle of Leyte Gulf, and both were lost in the early hours of 25 October 1944 to torpedoes and naval gunfire. Some eyewitnesses later claimed that ''Fusō'' broke in half, and that both halves remained afloat and burning for an hour, but historian Anthony Tully has made the case that she simply sank after forty minutes of flooding. Six U.S. Navy battleships and eight cruisers were lying in wait for ''Yamashiro''; she did not survive the encounter, and Vice Admiral Shōji Nishimura went down with his ship. Only ten crewmembers from each ship survived.

Background

The design of the ''Fusō''-class battleships was shaped both by the ongoing international naval arms race and a desire among Japanese naval planners to maintain a fleet of capital ships powerful enough to defeat the United States Navy in an encounter in Japanese territorial waters.Stille, p. 4 The IJN's fleet of battleships had proven highly successful in 1905, the last year of the Russo-Japanese War, which culminated in the destruction of the Russian Second and Third Pacific Squadrons at the Battle of Tsushima.

In the aftermath, the Japanese Empire immediately turned its focus to the two remaining rivals for imperial dominance in the Pacific Ocean: Britain and the United States. Satō Tetsutarō, a Japanese Navy admiral and military theorist, speculated that conflict would inevitably arise between Japan and at least one of its two main rivals. To that end, he called for the Japanese Navy to maintain a fleet with at least 70% as many capital ships as the US Navy.Evans & Peattie, p. 143 This ratio, Satō theorized, would enable the Imperial Japanese Navy to defeat the US Navy in one major battle in Japanese waters in any eventual conflict. Accordingly, the 1907 Imperial Defense Policy called for the construction of a battle fleet of eight modern battleships, each, and eight modern armored cruisers, each.Evans & Peattie, p. 150 This was the genesis of the Eight-Eight Fleet Program, the development of a cohesive battle line of sixteen capital ships.Stille, p. 7

The launch of in 1906 by the Royal Navy raised the stakes, and complicated Japan's plans. Displacing and armed with ten guns, ''Dreadnought'' rendered all existing battleships obsolete by comparison. The launch of the battlecruiser the following year was a further setback for Japan's quest for parity. When the two new s and two armored cruisers, launched by 1911, were outclassed by their British counterparts, the Eight-Eight Fleet Program was restarted.

The first battleships built for the renewed Eight-Eight Fleet Program were the two dreadnoughts of the , ordered in 1907 and laid down in 1908. In 1910, the Navy put forward a request to the Diet (parliament) to secure funding for the entirety of the program at once. Because of economic constraints, the proposal was cut first by the Navy Ministry to seven battleships and three battlecruisers, then by the cabinet to four armored cruisers and a single battleship. The Diet amended this by authorizing the construction of four battlecruisers (the ) and one battleship, later named ''Fusō'', in what became the Naval Emergency Expansion bill.Evans & Peattie, p. 160

Design

''Fusō'' was designed to work in conjunction with the four battlecruisers.Evans & Peattie, p. 165 After coordination with the British on the ''Kongō'' class, Japanese designers had access to the latest British design studies in naval architecture and were now able to design their own capital ships.Skulski, p. 11 In an effort to outmatch the American , planners called for a ship armed with twelve guns and faster than the of their rivals.Stille, p. 21 Vickers files show that the Japanese had access to the designs for double- and triple-gun turrets, yet opted for six double turrets over four triple turrets.

The final design—designated A-64 by the IJN—called for a displacement of with twelve guns in six double turrets (two forward, two aft, two separated amidships) with a top speed of .Evans & Peattie, p. 166 This design was superior to its American counterparts in armament, armor and speed, thus following the doctrine the Japanese had used since the First Sino-Japanese War of 1894–95 of compensating for quantitative inferiority with qualitative superiority.

Description

The ships had a length of overall. They had a beam of and a draft of . They displaced at standard load.Jentschura, Jung & Mickel, p. 25 Their crew consisted of 1,198 officers and enlisted men in 1915 and 1,396 in 1935. During World War II, the crew probably totalled around 1,800–1,900 men.

During the ships' modernization during the 1930s, their forward superstructures were enlarged with multiple platforms added to their tripod foremasts. The rear superstructures were rebuilt to accommodate mounts for anti-aircraft (AA) guns and additional fire-control directors. Both ships were also given torpedo bulges to improve their underwater protection and to compensate for the weight of the additional armor. In addition, their sterns were lengthened by . These changes increased their overall length to , their beam to and their draft to . Their displacement increased nearly to at deep load.

Propulsion

The ''Fusō''-class ships had two sets of Brown-Curtis direct-drive steam turbines, each of which drove two propeller shafts. The medium-pressure turbines drove the wing shafts while the high- and low-pressure turbines drove the inner shafts. The turbines were designed to produce a total of , using steam provided by 24 Miyahara-type water-tube boilers, each of which consumed a mixture of coal and oil. The ships had a stowage capacity of of coal and of fuel oil,Skulski, p. 17 giving them a range of at a speed of . Both ships exceeded their designed speed of during their sea trials; ''Fusō'' reached from and ''Yamashiro'' exceeded that with from .

During their 1930s modernization, the Miyahara boilers on each ship were replaced by six new Kanpon oil-fired boilers, fitted into the former aft boiler room, and the forward funnel was removed. The Brown-Curtis turbines were replaced by four geared Kanpon turbines with a designed output of . On her trials, ''Fusō'' reached a top speed of from . The fuel storage of the ships was increased to a total of of fuel oil that gave them a range of at a speed of .

Armament

The twelve 45- calibre 14-inch guns of the ''Fusō'' class were mounted in six twin-gun turrets, numbered from front to rear, each of which weighed . The turrets had an elevation capability of −5/+20 degrees.Skulski, p. 18 They were arranged in an uncommon 2-1-1-2 style with superfiring pairs of turrets fore and aft; the middle turrets were not superfiring, and had a funnel between them. The decision to use six twin turrets rather than four triple turrets greatly affected the entire design of the class because the two extra turrets required a longer ship and increased the amount of armor required to protect the ship. The location of the third and fourth turrets proved particularly problematic to the design of the class because the amidships turrets were not superfiring as in the subsequent s. This further increased the length of the ships because the barrels of the upper turret did not protrude over the lower turret, requiring more space than a pair of superfiring turrets. Mounted amidships along the centerline of the ship, they had restricted arcs of fire, and their position forced the boiler rooms to be placed in less than ideal locations. Another complication was the need to fit extra insulation and air conditioning in the magazines of the amidships turrets to protect them from the heat generated in the adjacent boiler rooms. Originally both amidship gun turrets faced to the rear, but ''Fusō''s turret No. 3 was moved to face forward during her reconstruction in order to accommodate additional platforms around her funnel.

The main battery of the ''Fusō'' class underwent multiple modernizations throughout the ships' careers. During the first reconstruction of both vessels, the elevation of the main guns was increased to −5/+43 degrees, giving a maximum firing range of . The recoil mechanism of the guns was also changed from a hydraulic to pneumatic system, which allowed for a faster firing cycle of the main guns.

By World War II, the guns used Type 91 armor-piercing, capped shells. Each of these shells weighed and had a muzzle velocity of . They had a maximum range of at +30 degrees of elevation and at +43 degrees after modernization.Skulski, p. 19 Also available was a high-explosive shell that had a muzzle velocity of . A special Type 3 '' Sankaidan'' incendiary shrapnel shell was developed in the 1930s for anti-aircraft use.

As built, the ''Fusō'' class was fitted with a secondary armament of sixteen 50-caliber six-inch guns mounted in single casemates along the sides of the hull at the level of the upper deck. Eight guns were mounted per side, and each had an arc of fire of 130 degrees and a maximum elevation of +15 degrees. Each gun could fire a high-explosive projectile a maximum distance of at a rate of between four and six shots per minute. During their reconstruction in the 1930s, the maximum elevation of the guns was increased to +30 degrees, which increased their maximum range by approximately .Skulski, p. 20

The ships also mounted five or six 40-caliber 76 mm anti-aircraft (AA) guns. The high-angle guns were in single mounts on both sides of the forward superstructure, both sides of the second funnel, and each side of the aft superstructure (''Fusō'' lacked the starboard side aft gun). Each of these guns had a maximum elevation of +75 degrees, and could fire a projectile with a muzzle velocity of to a maximum height of . Both ships were equipped with six submerged torpedo tubes, three on each broadside.

The ''Fusō'' class's secondary armament changed significantly over time. During the modernizations of the 1930s, all of the 76 mm guns were replaced with eight 40-caliber dual-purpose guns. These guns were fitted on both sides of the fore and aft superstructures in four twin-gun mounts. When firing at surface targets, the guns had a range of ; they had a maximum ceiling of at their maximum elevation of +90 degrees. Their maximum rate of fire was 14 rounds a minute, but their sustained rate of fire was around eight rounds per minute. During reconstruction, the two foremost 152 mm guns were also removed.Skulski, p. 30

The light AA armament of the ''Fusō'' class changed dramatically from 1933 to 1944. During the first reconstruction, ''Fusō'' was fitted with four quadruple machine-guns,Skulski, p. 21 while ''Yamashiro'' was fitted with eight twin gun mounts.Stille, p. 22 Both weapons were license-built French Hotchkiss designs. The 25 mm guns were mounted on the ''Fusō'' class in single, double and triple mounts. This model was the standard Japanese light anti-aircraft gun during World War II, but it suffered from severe design shortcomings that rendered it a largely ineffective weapon. The twin and triple mounts "lacked sufficient speed in train or elevation; the gun sights were unable to handle fast targets; the gun exhibited excessive vibration; the magazine was too small, and, finally, the gun produced excessive muzzle blast".Stille, p. 11 The configuration of the anti-aircraft guns varied significantly; by the end of their final reconstruction, the ''Fusō'' class mounted eight twin mounts. In 1943, seventeen single and two twin-mounts were added for a total of 37.Stille, p. 23 In August 1944, both were fitted with another twenty-three single, six twin and eight triple-mounts, for a total of 96 anti-aircraft guns in their final configuration.Skulski, p. 22

Armor

When the ''Fusō'' class was completed, the ships' armor was "typical for a pre-Jutland battleship".Skulski, p. 16 As built, the armor accounted for a displacement of , approximately 29% of the class's total displacement. Their waterline armor belt was thick; below it was a strake of armor. The deck armor ranged in thickness from . The turrets were protected with an armor thickness of on the face, on the sides, and on the roof. The barbettes of the turrets were protected by armor 305 mm thick, while the casemates of the 152 mm guns were protected by 152 mm armor plates. The sides of the conning tower were thick. Additionally, the vessels contained 737 watertight compartments (574 underneath the armor deck, 163 above) to preserve buoyancy in the event of battle damage.

During their reconstruction, the armor of the battleships was substantially upgraded. Their deck armor was increased to a maximum thickness of , and a longitudinal bulkhead of of high-tensile steel was added to improve the underwater protection. This brought the total armor tonnage up to , approximately 31% of the total displacement of the ''Fusō'' class. Even after these improvements, the armor was still incapable of withstanding 14-inch shells.

Aircraft

''Yamashiro'' was briefly fitted with an aircraft flying-off platform on Turret No. 2 in 1922. She successfully launched Gloster Sparrowhawk and Sopwith Camel fighters from it, becoming the first Japanese ship to launch aircraft. When she was modernized in the 1930s, a catapult and a collapsible crane were fitted on the stern, and both ships were equipped to operate three floatplanes, although no hangar was provided. The initial Nakajima E4N2 biplanes were replaced by Nakajima E8N2 biplanes in 1938 and then by Mitsubishi F1M biplanes from 1942 on.

Fire control and sensors

When completed in 1915, the ships had two and two rangefinders in the forward superstructure, a rangefinder on the roof of Turret No. 2, and 4.5-meter rangefinders in Turrets 3, 4, and 5. In late 1917 a fire-control director was installed on a platform on the foremast. The 4.5-meter rangefinders were replaced by instruments in 1923. During ''Fusō''s first modernization, four directors for the 12.7 cm AA guns were added, one on each side of the fore and aft superstructures, and an eight-meter rangefinder was installed at the top of the pagoda mast. This was replaced by a rangefinder during 1938. At the same time, the two 3.5-meter rangefinders on the forward superstructure were replaced by directors for the 25 mm AA guns. Additional 25 mm directors were installed on platforms on each side of the funnel.

While the ships were in drydock in July 1943, Type 21 air search radar was installed on the roof of the 10-meter rangefinder at the top of the pagoda mast. In August 1944, two Type 22 surface search radar units were installed on the pagoda mast and two Type 13 early warning radar units were fitted. ''Yamashiro'' mounted hers on the mainmast, while ''Fusō'' was the only Japanese battleship to mount radar on her funnel.

Ships

Two advanced versions of the class were planned, but the final design differed so markedly from ''Fusō'' that they became the ''Ise'' class. When she was completed in 1915, ''Fusō'' was considered the first modern battleship of the Japanese Navy. She outclassed her American counterparts of the in firepower and speed, and was considered the "most powerfully armed battleship in the world". Despite extensive modernization in the 1930s, both battleships were considered obsolescent by the commencement of World War II. Following the loss of much of Japan's aircraft carrier fleet by 1943, a proposal was floated that would have converted both vessels into hybrid battleship-carriers. Work was scheduled to commence in June 1943, but the plan was cancelled and the two ''Ise''-class battleships were converted instead.Gardiner & Gray, p. 229

Service

''Fusō'' was commissioned on 8 November 1915 and assigned to the 1st DivisionSkulski and Preston use Squadron while Hackett uses BatDiv, presumably Battleship Division. of the 1st Fleet on 13 December.Skulski, p. 12 The ship did not take part in any combat during World War I, as there were no longer any forces of the Central Powers in Asia by the time she was completed. She served as the flagship of the 1st Division during 1917 and 1918,Preston, p. 199 and patrolled off the coast of China during that time. The ship aided survivors of the Great Kanto Earthquake between 9 and 22 September 1923. In the 1920s, ''Fusō'' conducted training off the coast of China and was often placed in reserve. After assignment as a training ship in 1936 and 1937, she briefly operated in Chinese waters in early 1939.

''Yamashiro'' was completed on 31 March 1917 and assigned to the 1st Division of the 1st Fleet in 1917–18, though she had no combat role in World War I. Like her sister, she patrolled off the coast of China during the war and assisted during the Great Kanto Earthquake. Little detailed information is available about her activities during the 1920s, although she did make a port visit to Port Arthur, China, on 5 April 1925 and also conducted training off the coast of China. ''Yamashiro'' became flagship of the Combined Fleet in 1935. In early 1941, the ship experimentally launched radio-controlled Kawanishi E7K2 floatplanes.

World War II

In April and May 1941, ''Fusō'' and ''Yamashiro'' were attached to the 2nd Division of the 1st Fleet, but the two ships spent most of the war around Japan, mostly at the anchorage at Hashirajima in Hiroshima Bay. When the war started for Japan on 8 December,Japan Standard Time is 19 hours ahead of Hawaiian Standard Time, so in Japan, the attack on Pearl Harbor happened on 8 December. the division sortied from Hashirajima to the Bonin Islands as distant support for the 1st Air Fleet attacking Pearl Harbor, and returned six days later.Hackett (2010) On 18 April 1942, they pursued but did not catch the American carrier force that had launched the Doolittle Raid. Commanded by Vice-Admiral Shirō Takasu, the division set sail with the Aleutian Support Group on 28 May, at the same time that most of the Imperial Fleet began an attack on Midway Island ( Operation MI).

Afterwards, ''Yamashiro'' returned to home waters, where she stayed until August 1943; the next month, she became a training ship for midshipmen. In July 1943, ''Yamashiro'' was at the Yokosuka drydock, then was briefly assigned as a training ship on 15 September before loading troops on 13 October bound for Truk Naval Base, arriving on the 20th. She sailed for Japan on 31 October. On 8 November, the submarine fired torpedoes at ''Junyo'' that missed, but hit ''Yamashiro'' with a torpedo that failed to detonate. Returning to Japanese waters, ''Yamashiro'' resumed her training duties.

During the US invasion of Saipan in June 1944, Japanese troop ships attempting to reinforce the defenses were sunk by submarines. Shigenori Kami, chief of operations of the Navy Staff, volunteered to command ''Yamashiro'' to carry troops and equipment to Saipan. If the ship actually reached the island, he intended to deliberately beach the ship before it could be sunk and to use its artillery to defend the island. After Ryūnosuke Kusaka, Chief of Staff of the Combined Fleet, also volunteered to go, Prime Minister Hideki Tōjō approved the plan, known as Operation ''Y-GO'', but the operation was cancelled after the decisive defeat in the Battle of the Philippine Sea on 19 and 20 June.

''Fusō'' was assigned to the Imperial Japanese Naval Academy at Etajima, Hiroshima, for use as a training ship between 15 November 1942 and 15 January 1943. On 8 June, she rescued 353 survivors from ''Mutsu'' when that ship exploded at Hashirajima.Hackett (2003) After carrying supplies to Truk Naval Base in August, ''Fusō'' made for Eniwetok two months later to be in a position to intercept an anticipated attack, returning to Truk on October 26. She arrived on 21 February at Lingga Island, and was employed there as a training ship, before refitting at Singapore between 13 and 27 April and returning to Lingga. She was transferred to Tawi-Tawi on 11 May, and provided cover for the abortive attempts to reinforce Biak Island at the end of the month. ''Fusō'' sailed to Tarakan Island off Borneo to refuel in early July before returning to Japan, escaping an attack by the submarine . She was refitted in early August at Kure.

Both ships were transferred to Battleship Division 2 of the 2nd Fleet on 10 September. ''Yamashiro'' and ''Fusō'' alternated in the role of division flagship under Vice Admiral Shōji Nishimura. They departed Kure on 23 September for Lingga Island, carrying the Army's 25th Independent Mixed Regiment, and escaped an attack by the submarine the next day. They arrived on 4 October, then transferred to Brunei to offload their troops and refuel in preparation for Operation ''Shō-Gō'', the attempt to destroy the American fleet conducting the invasion of Leyte.

Battle of Surigao Strait

Nishimura's "Southern Force" left Brunei at 15:30 on 22 October 1944, heading east into the Sulu Sea and then to the northeast into the Mindanao Sea. Intending to join Vice-Admiral Takeo Kurita's force in Leyte Gulf, they passed west of Mindanao Island into Surigao Strait, where they met a large force of battleships, cruisers and destroyers lying in wait. The Battle of Surigao Strait would become the southernmost action in the Battle of Leyte Gulf.

At 09:08 on 24 October, ''Yamashiro'', ''Fusō'' and the heavy cruiser spotted a group of 27 planes, including Grumman TBF Avenger torpedo bombers and Curtiss SB2C Helldiver dive bombers escorted by Grumman F6F Hellcat fighters, that had been launched from the carrier . Around 20 sailors on ''Yamashiro'' were killed by strafing and rocket attacks. ''Fusō'' catapult and both floatplanes were destroyed, and another bomb hit the ship near Turret No. 2 and penetrated the decks, killing everyone in No. 1 secondary battery.

Nishimura issued a telegram to Admiral Soemu Toyoda at 20:13: "It is my plan to charge into Leyte Gulf to eacha point off Dulag at 04:00 hours on the 25th." At 22:52, his force spotted three or four Motor Torpedo Boats and opened fire, damaging and and forcing all of them to retreat before they could launch their torpedoes.

One or two torpedoes, possibly fired by the destroyer , hit ''Fusō'' amidships on the starboard side at 03:09 on the 25th; she listed to starboard, slowed down, and fell out of formation. Some Japanese and American eyewitnesses later claimed that ''Fusō'' broke in half, and that both halves remained afloat and burning for an hour, but they specifically mentioned only the size of the fire on the water, and not any details of the ship. Historian John Toland agreed in 1970 that ''Fusō'' had broken in two, but according to historian Anthony Tully in 2009, "Fuso was torpedoed, and as a result of progressive flooding, upended and capsized within forty minutes." She sank between 03:38 and 03:50; only a few dozen men survived her rapid descent and massive oil fire, and only ten reached shore.

At 03:52, ''Yamashiro'' was attacked by a large formation to the north commanded by Rear Admiral Jesse Oldendorf. First came 6- and shells from a line of eight cruisers, then and shells from a line of six battleships. The main bombardment lasted 18 minutes, and ''Yamashiro'' was the only target for seven minutes. The first rounds hit the forecastle and pagoda mast, and soon the entire battleship appeared to be ablaze. ''Yamashiro'' two forward turrets targeted her assailants, and the secondary armament targeted the American destroyers plaguing ''Mogami'' and the destroyer . There was a big explosion at 04:04, possibly from one of the middle turrets. She was hit between 04:03 and 04:09 near the starboard engine room by a torpedo, and Nishimura wired to Kurita: "We proceed till totally annihilated. I have definitely accomplished my mission as pre-arranged. Please rest assured." At the same time, Oldendorf issued a cease-fire order to the entire formation after hearing that the destroyer was taking friendly fire, and the Japanese ships also ceased fire.Tully, pp. 214–215

''Yamashiro'' increased speed, but she had been hit by two to four torpedoes, and after two more torpedo hits near the starboard engine room, she was listing 45 degrees to port. Shinoda gave the command to abandon ship, but neither he nor Nishimura made any attempt to leave the conning tower as the ship capsized within five minutes and quickly sank, stern first, vanishing from radar between 04:19 and 04:21. Only 10 crewmembers of the estimated 1,636 officers and crew on board survived.Tully, p. 218

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{{DEFAULTSORT:Fuso class battleship
Battleship classes