was the lead ship in the two-vessel of heavy cruisers in the Imperial Japanese Navy. The ship was named after Mount Furutaka, located on Etajima, Hiroshima, immediately behind the Imperial Japanese Navy Academy. She was commissioned in 1926 and was sunk 12 October 1942 by and USS Buchanan at the Battle of Cape Esperance.

Design

Design work on the of heavy cruisers began in the late 1910s in conjunction with the experimental light cruiser under the direction of noted naval engineer Yuzuru Hiraga. Both types incorporated radical weight-saving measures including using the side belt armor as part of the hull's structural strength. The Furutaka-class cruisers were intended to counter the American and British s. Despite Hiraga's efforts, the two Furutaka-class ships were about overweight.

Characteristics

Furutaka was long overall and had a beam of and a draft of . She displaced normally and up to at full load. The ship's superstructure consisted of a large conning tower and bridge structure forward and a smaller, secondary structure aft. Her hull had a flush deck that had an unusual wavy profile that gradually reduced in height from bow to stern. Furutaka had a crew of 45 officers and 559 enlisted men.

Her propulsion system consisted of four geared steam turbines that drove four screw propellers. Steam was provided by twelve water-tube boilers that burned oil and coal; the boilers were vented through three uptakes, the first two of which were ducted together into a single large funnel. The ship's propulsion system was rated to produce for a top speed of . While steaming at a more economical speed of , the ship could cruise for up to .

The ship was armed with a main battery of six /50 guns in single gun turrets. The turrets were arranged in groups of three on the centerline; the forward set consisted of two forward-facing mounts, one superfiring over the other, with the third turret immediately behind, facing rearward. The aft set of three turrets were mirrored in the same pattern: two turrets facing aft, one superfiring over the other, and the other turret just ahead, facing forward. All six turrets could fire to either broadside. In addition, Furutaka fitted with four anti-aircraft guns mounted individually, along with a pair of Lewis guns for close-range defense. The ship carried a heavy torpedo armament consisting of twelve torpedo tubes. These were arranged in fixed pairs along the side of the ship.

Furutaka was protected by an armor belt that was thick along with an armor deck that was thick; the deck connected to the top of the belt. The ammunition magazines received of armor protection, and the main battery turrets had a maximum thickness of . The armor layout was only intended to defeat shells. And because the ship was badly overweight, the belt was partially submerged, which reduced its effectiveness.

Modifications

Furutaka underwent a series of significant refits, beginning with modifications to her funnels in late 1926 and early 1927; smoke from the funnels caused excessive interference with the bridge and other control platforms. Accordingly, the funnels were increased in height and their caps were altered. The ship next saw another shipyard period in 1930, when the flying-off platform for her aircraft was removed. Furutaka was modernized at Kure Naval Base in 1932–1933, receiving new anti-aircraft guns, an aircraft catapult, and a Nakajima E4N2 floatplane. The old 7.6 cm anti-aircraft guns were replaced with an equal number of /45 guns, which were fitted in individual mounts with gun shields. Four Hotchkiss machine guns were installed in twin mounts on sponsons that were added to the forward conning tower.

A more extensive reconstruction took place from April 1937 to April 1939, also at Kure. The six single Mark I main battery was replaced by three twin-turrets housing the /50-cal Mark I guns from Haguro and Ashigara re-bored to Mark II, as there was a shortage of Mark II guns at this time. The 12 cm guns were rearranged to clear space for storage space for additional torpedoes. Four more 13.2 mm machine guns were added to the forward conning tower, along with a control room to direct all of those guns. The original fixed torpedo tubes were replaced with a pair of trainable quadruple mounts on the upper deck. They were initially supplied with Type 90 torpedoes, but by 1940, these had been replaced by the Type 93 torpedoes (well known as the "Long Lance").

The forward conning tower was rebuilt and improved fire-control equipment was installed. Her mixed coal-and-oil-burning boilers were replaced with ten purely oil-fired Kanpon boilers. Facilities were upgraded for two E7K2 floatplanes. All of the changes resulted in a significant growth in displacement, to standard and at full load. Large bulges were installed to maintain the ship's draft despite the increased weight of the new equipment; this had the added benefit of improving the strength of the hull and resistance to underwater damage. The improvements increased her crew to 50 officers and 589 enlisted sailors.

During a refit in September 1941, a degaussing coil was installed.

Service history

Inter-war period

1922–1930 Construction of Furutaka and her sister ship Kako were authorized in March 1922, and contracts were placed for the two vessels on 22 June. The keel for the new cruiser was laid down on 5 December that year at the Mitsubishi shipyard in Nagasaki. Civil unrest in Japan in 1923 slowed work on the ship. Her completed hull was launched on 25 February 1925, and fitting-out work was scheduled to be completed by 23 November. Problems with the ship's turbines during sea trials delayed completion until 31 March 1926, the day she was commissioned into active service. Upon entering service, Furutaka was assigned to Cruiser Division 5, along with Kako and the light cruisers , , and ; the cruisers were initially based at Yokosuka Naval Arsenal. Furutaka became the divisional flagship.

On 9 May 1926, Furutaka made a short trip from Yokohama to Shimoda with a number of senior government officials aboard, including Vice Admiral Prince Fushimi Hiroyasu; Prime Minister Wakatsuki Reijirō; and Navy Minister Takarabe Takeshi. Kako replaced Furutaka as the division flagship on 1 December while the latter underwent modifications that lasted into February 1927. By that time, the ships assigned to the division were the two Furutakas and the light cruisers and . Furutaka rejoined the unit for a cruise to China that began on 27 March, which included a stop in Amoy, China, along with Makung in the Pescadores. By 26 April, the ships had arrived back in Japan, stopping first at Sasebo. Summer training exercises with the rest of the fleet were held in the Bungo Channel. During the first phase of the maneuvers in August, Naka and Jintsū were damaged in collisions, leaving just Furutaka and Kako to operate during the second phase conducted in September and October. The exercises concluded with a fleet review off Yokohama on 30 October. The two recently completed s joined Furutaka and Kako in Cruiser Division 5 in December, becoming the new division flagship. Furutaka went into the shipyard for alterations between 2 and 16 December.

Furutaka and the rest of the division sailed on 29 May 1928, bound for Qingdao, China. From there, they proceeded to Ryojun in the Kwantung Leased Territory, arriving on 9 April. The ships then moved to Dairen, also in the Kwangtung territory, where they joined the second expedition to Shandong, China. The Japanese force brought soldiers to Qingdao in response to fighting during the Northern Expedition that threatened Japanese interests in the area, which led to the Jinan incident. Furutaka and the other cruisers thereafter returned home, and they were present for the annual summer and autumn maneuvers. All four vessels participated in a major fleet review held on 4 December to mark the coronation of Emperor Hirohito. Furutaka and the other cruisers made another cruise to Shandong and then Ryojun that began on 28 March 1929 and concluded in April. Furutaka was placed in reserve on 7 November for the modification work that lasted until 1 December 1930.

1930–1941

Upon returning to active service after the conclusion of her refit, Furutaka rejoined Cruiser Division 5; at the same time, Kako and Kinugasa were decommissioned for their refits, leaving just in the unit with her. The two cruisers visited Qingdao in April 1931. After returning to Yokosuka the following month, Furutaka was dry docked for periodic maintenance that lasted from 29 May to 29 September. She and Aoba were also decommissioned on 1 December, leaving Cruiser Division 5 without active units. Furutaka was moved to Kure on 1 February 1932, where she was dry docked again for repairs to her hull that lasted from 23 February to 30 April. Furutaka remained in reserve until 15 November 1933, when she was assigned to Cruiser Division 6, by which time her sister and the two Aobas had already been transferred there. Furutaka was soon dry docked at Kure for needed updates, including the installation of a new wireless system, which lasted from 20 November to 31 January 1934. Damage to her hull necessitated emergency repairs at Maizuru Naval Arsenal from 5 to 8 September. The ship then joined the other two cruisers of the division at Ryojun for another voyage to Tsingtao, which concluded in Sasebo on 5 October.

The three cruisers of 6th division sailed on 29 March 1935 for another short cruise in Chinese waters, this time off the mouth of the Yangtze. Furutaka and the others arrived back in Yokosuka on 4 April. Another dry docking followed for Furutaka for repairs that lasted from 28 May to 20 June. She thereafter rejoined the unit for the annual summer and autumn maneuvers. The ship was placed back in reserve on 15 November, attached to the Kure Guard Squadron. She remained there until 15 February 1936, after which she laid idle until 6 March 1937, when she was taken into the shipyard at Kure for her major reconstruction, which lasted until 30 April 1939. This was earlier than originally planned, because the ship had suffered some damage to her turbine blades in 1935–1936, and was in need of an engine overhaul. After the turrets and torpedo tubes were removed at Kure, Furutaka was moved temporarily to the Osaka Iron Works for alterations to her hull.

As the four Furutaka and Aoba-class cruisers began to return to service after their reconstructions, they were assigned again to Cruiser Division 6, then part of the 1st Fleet. By early 1940, this consisted of only Kinugasa (the flagship) and Furutaka. The two cruisers embarked on a cruise to south China on 26 March 1940, concluding in Takao, Japan, on 2 April. They then sailed into the Seto Inland Sea for training exercises. The two cruisers were present for another fleet review on 11 October, which marked the 2,600th anniversary of the founding of Japan. The following month, Aoba rejoined the unit, and on 1 March 1941, Kinugasa restored the division to full strength. The other three cruisers had already sailed to patrol in Chinese waters on 24 February, arriving back in the Inland Sea on 3 March. Furutaka and Kako conducted a short cruise in Japanese waters from 5 to 14 September. Furutaka thereafter entered dry dock at Kure for periodic maintenance. As preparations for the upcoming, wide-ranging offensives against Anglo-American forces began in earnest in late 1941, Furutaka and the rest of the division conducted combat drills in mid-October. On 1 November, they were allocated to the South Seas Force. More training followed in the Bungo Channel through the first half of November, after which the cruisers returned to Kure to load fuel, ammunition, and other supplies. They sailed for Hahajima in the Bonin Islands, arriving there on 2 December; by that time, the division had come under the command of Rear Admiral Aritomo Goto.

World War II