Fuso class

2023-02-01 -

IJN FUSO

During WWI Japan built its first superdreadnoughts, IJN Fuso (completed November 1915 at Kure) and IJN Yamashiro (completed March 1917 at Yokosuka) under the Japan’s Emergency Expansion Program. At that time they were the most powerfully armed battleships in the world with 14in (35.6cm) guns in six twin turrets along the centreline arranged in an uncommon 2-11-2 style, with superfiring pairs of turrets fore and aft, plus very fast at 23 knots.

The centre twin turrets were singular either side of the funnel, which restricted their arc of fire, an issue overcome with the later Ise class battleships.

Fuso and Yamashiro were named after the provinces of Old Japan and underwent extensive conversions between 1927-28 and 1935-36 under Japan’s battleship modernisation program.

The first phase improvements included adding multiple platforms to the forward and aft superstructure to accommodate additional anti-aircraft mounts and firecontrol directors.

The mid-1930’s modernisation included new engines and boilers fitted, torpedo bulges added for underwater protection, forward funnel removed, elevation of main battery increased to 43 degrees to provide a greater range of 22km (13.5 miles). Better armour protection was added and each ship was lengthened in the stern by 7.62m (25ft). The tripod masts were reconstructed into pagoda superstructures and their rear superstructure rebuilt. All this extra weight increased the battleship’s displacement by 4,100 tonnes. The change from coal to oil-fired boilers increased both ship’s range by over 30% and the addition of a stern catapult and hanger for three float planes provided long-range reconnaissance. Nevertheless, by 1941 standards both battleships were old and slow and were initially assigned to auxiliary roles.

Fuso and Yamashiro always served together during the Pacific War and were ultimately sunk together. In December 1941, the sister ships acted as support for the 1st Air Fleet’s six-carrier attack on Pearl Harbor. On 18 April 1942 Fuso and Yamashiro pursued the Doolittle Raid, which had just launched a daring air raid on Tokyo with 16 B-25B Mitchell Bombers launched from the carrier USS Hornet, but the pair returned four days later without making contact. The two sister ships set sail on 28 May 1942 as part of the Support Group of Northern Force for the successful invasion of the Aleutian Islands, an Alaska USA territory, a side-issue during the Battle of Midway. It was at this time that Fuso and Yamashiro were planned to become unprecedented battleship-carriers by having large flight decks constructed in place of their two aft gun turrets to match that of the battleships Ise and Hyuga; the decision an emergency measure due to the loss of four fleet carriers at Midway in June 1942, but the plan was cancelled due to shipyard congestion. When the battleship IJN Mutsu suffered an internal explosion at Hashirajima on 8 June 1943, IJN Fuso was on hand to rescue 353 men, the only survivors of Mutsu’s 1,474 crew.

During the Battle of Leyte Gulf, the Japanese attempted to destroy the landing ships of the US Sixth Army’s invasion of Leyte in the Philippines on 25 October 1944. However, two torpedoes fired from American destroyers hit Fuso whilst negotiating the Surigao Straight in company with Yamashiro, and other ships, causing the Fuso to catch fire and fall out of line.

She began to list badly due to progressive flooding and subsequently capsized,

IJN Fuso

Class: Fuso

Displacement: 37,500 tonnes

Length: 212.7m (697ft 10in)

Beam: 33.1m (108ft 7in)

Draft: 9.7m (31ft 10in)

Speed: 24.7 knots

Range: 21,887km (13,600 miles)

Crew: 1,650 men

Armament: 12 x twin 14in guns • 14 x single 6in guns • 4 x twin 5in DP/AA guns • 95 x 25mm AA guns • 3 x Mitsubishi F1M float-plane reconnaissance aircraft

Armour: Deck - 152mm (6in), Waterline belt 305mm (12in)

IJN ISE

IJN Ise was the lead ship of her class of two dreadnought battleships completed between December 1917 and April 1918 as an improvement of the Fuso class, but neither played any role during WWI. Ise and her sister ship Hyuga, were named after Japanese provinces, the former built by Kawasaki Heavy Industries in Kobe and completed on 15 December 1917, whilst the latter was laid down at the Mitsubishi Heavy Industries in Nagasaki and completed on 30 April 1918. The ships were built with a dozen 14in (35.6cm) guns mounted in three pairs of twin superfiring turrets numbered one through six from front to rear. The first pair were forward of the main superstructure, the second pair were amidships (uniquely superfiring and not conventionally situated either side of the funnel) and the third pair aft of the rear superstructure. On completion as dreadnoughts the pair resembled the British Royal Sovereign class. During modernisation 1928-32, both ships converted from coal to oil and were upgraded with the unique Japanese pagoda superstructure, which completely altered their appearance and silhouette. Ise and Hyuga were totally modernised between 1934 and 1937, both receiving new engines and boilers, the forward funnel removed, bulges added, thicker deck armour and new pagoda foremast, but despite expensive reconstruction, the class was nevertheless considered obsolete by the eve of the Pacific War, seeing little action before 1944.

The loss of four fleet carriers during the Battle of Midway in June 1942, caused Imperial Naval Headquarters to seek alternative solutions, but plans to convert battleships into aircraft carriers was rejected due to the expense and the time this would take. Eventually it was decided to rebuild Ise and Hyuga with a superimposed flight deck aft, creating the unique concept of the hybrid battleshipcarrier. Work commenced in February

1943 removing the aft No. 6 and No. 7 turrets (each weighing 864 tonnes) the barbets and supporting structures.

The openings in the middle deck were covered by 152mm plates salvaged from the turret armour. All aft 5.5in AA guns were removed and the casemate openings sealed off. Each flight deck measured 70m long by 29m wide fitted with two rotating gunpowder-propelled catapults and a ‘T’ shaped lift; but the two-story hanger below accommodated only nine aircraft, the balance needing to be secured on deck. The flight deck overhang increased the length of the ships to 220m, whilst the weight saved considerably reduced their displacement. Each proposed air group was 12 Yokosuka D4Y dive-bombers modified for catapult launching and 10-12 Aichi E16A float-plane reconnaissance aircraft. These rebuilds were completed by

November 1943, but due to the lack of trained pilots and available aircraft, both ships languished, so that by June 1944 their intended hybrid role could not be realised this late in the war. Consequently, in September 1944 an extra 51 x 25mm anti-aircraft guns and 180 x 5in rocket launchers were fitted on each redundant flight deck, resulting in no air component carried when they returned to combat duty, simply because not enough planes and virtually no pilots ever became available. Ise and Hyuga served together throughout WWII. In her new guise as a battleship-carrier, Ise acted as a decoy during the Battle of Cape Engaño on 26 October 1944; after which for the next four months she transferred troops and much needed strategic supplies to Singapore. From 1 March 1945, Ise was placed in reserve at Kure Naval Base painted in an olive green/yellow camouflage scheme, but American carrier-borne air raids eventually sank her in shallow water on 28 July 1945, where she was later scrapped in situ by the British occupation authorities between October 1946 and July 1947.