NAVYPEDIA

Photo

  Kako 1930 Many thanks to Wolfgang Stöhr for additional information on this page.

Ships

Name	No	Yard No	Builder	Laid down	Launched	Comp	Fate
古鷹 [Furutaka]		390	Mitsubishi, Nagasaki	5.12.1922	25.2.1925	31.3.1926	sunk 11.10.1942
加古 [Kako]		540	Kawasaki, Kobe	17.11.1922	10.4.1925	20.7.1926	sunk 10.8.1942

Technical data

Displacement standard, t	8100
Displacement full, t	9544
Length, m	176.8 pp 183.5 wl 185.2 oa
Breadth, m	15.8
Draught, m	5.56
No of shafts	4
Machinery	Furutaka: 4 sets Mitsubishi-Parsons geared steam turbines, 12 Kampon boilers Kako: 4 sets Kawasaki-Curtis geared steam turbines, 12 Kampon boilers
Power, h. p.	102000
Max speed, kts	34.5
Fuel, t	oil 1010, coal 570
Endurance, nm(kts)	6000(14)
Armour, mm	belt: 76, deck: 35, turrets: 25
Armament	6 x 1 - 200/50 3-shiki, 4 x 1 - 76/40 11-shiki, 2 x 1 - 7.7/80, 12 - 610 TT (beam), 1 seaplane (HD-26)
Complement	625

Standard scale images

Graphics

Project history

The history of creation of Furutaka class cruisers goes back to 1916 when three "scouts" have been included into the "8-4" Programme (7200t standard displacement, 36kts, 12 140mm guns in single and twin mounts, 610mm TT and 76mm belt). When in Japan it became known about building of Omaha class cruisers in the USA, it has been decided to redesign project, and the place of "scouts" in the program was held by "standard" 5500t cruisers. In 1918 in technical department the modified "scout" design (8000t standard, 36.5kts, 10-12 140mm guns in 5-6 twin turrets arranged in at centreline pyramidally) has been prepared. Building was provided by program "8-8", however order delivery again have put aside: this time the big impression on Japanese admirals British Hawkins class cruisers with 190mm guns have effected. Project of "scout" again have shipped on redesigning.

In summer 1921, for half a year before signing of Washington Treaty, chief of Naval technical department captain Yuzusu Hiraga has created new design of 7500t scout. In it at expense of application of some constructive innovations attempt to combine in minimum possible displacement the artillery exceeding 190mm guns of Hawkins, speed not less than 35kts, better, than on the US and British cruisers, protection and a sufficient endurance has been undertaken. Including of side and deck protection into hull strength framing became the basic innovation directed on hull weight reduction. Hull was fulfilled flush-decked, and upper deck in a direction from stem aftward received characteristic for many subsequent Japanese ships "wavy" profile. The greatest freeboard height (8.5m) was at stem, amidships this characteristic got out of a reason of a necessary stability, and aft was fulfilled as far as possible low (4.5m). The majority of constructive innovations has been tested on light cruiser Yubari, specially constructed for this purpose.

Armour of new cruisers ensured protection against 152mm shells on distances from 12000 to 15000m. 76mm belt with 80m length had a declination 9° outside. Its upper edge was connected with 35mm deck which thickness decreased to 32mm closer to centerline.

The pyramidal arrangement of main artillery was borrowed the "scout" of 1918, but now six turrets had 200mm/50 guns. Additionally there were 4 AA 76mm guns and 12 610mm fixed TTs placed aside.

4-shaft machinery with 102000hp power included geared turbines. The steam for them was generated by 12 boilers, 10 from which had purely oil, and two mixed heating. Full stowage of fuel included 1010t oil and 570t coal that ensured an endurance of 6000 miles at 14kts.

At building of these ships the lack generic in Japanese shipbuilding of that time showed: extremely big building overload which has reached in this case 1000t (under the design standard displacement was 7100t, normal at 2.3 fuel stowage 8450t; the actual made 8100 and 9433t respectively). Decrease in a designed speed from 35 to 34.5kts became overload corollary.

In 1936-1939 Furutaka and Kako have passed cardinal modernization, they have lost a unique pyramidal arrangement of main artillery: single turrets were demounted and have replaced by twin, placed more traditionally, two in a fore end and one aft. Instead of fixed TTs 2 quadruple trainable mounts were installed with complete set of spare torpedoes. Changes have concerned also machinery: mixed-fuel boilers were demounted, that has allowed to moderate the sizes of second funnel, steam output of oil-firing boilers was raised. Oil stowage thus has increased to 1858t. As the armament weight has grown, for preservation of stability cruisers were fitted with bulges. Now the hull beam has reached 16.9m instead of former 15.8m.

Ship protection

76mm main belt (80x4.1m) protected machinery only and was slightly inclined outside (9°). It was connected with 35mm main deck by upper edge, thickness of main deck decreased to 32mm near centerline. Underwater protection consisted of bulges, there was not armored longitudinal bulkhead. Guns had only 25mm protection.

Modernizations

1932, Kako; 1933, Furutaka: - 4 x 1 - 76/40, 2 x 1 - 7.7/80; + 4 x 1 - 120/45 10-shiki, 2 x 2 - 13.2/76, 1 catapult (up to 2 seaplanes).

(7/1936 - 12.1937, Sasebo K K), Kako; (4/1937 - 4.1939, Kure K K), Furutaka: - 6 x 1 - 200/50, 12 - 610 TT; + 3 x 2 - 203/50 3-shiki 2-go, 4 x 2 - 25/60 96-shiki, 2 x 4 - 610 TT (16); main guns placed in turrets with 25mm armour and 57mm barbettes, CT received 36mm protection, catapult was replaced by more powerful one. Boilers were replaced by 10 oil-burning Kampon. Fuel stowage was 1858t of oil, endurance was 7900(14) nm(kts). Engine power increased to 110000hp (maximal speed was 33kts). New bulges were fitted, breadth rose to 16.9m and displacement to 8700/11273-11295 t. Complement was 639.

Naval service

Furutaka 11.10.1942 was sunk in battle of Cape Esperance by gunfire and torpedo of US cruisers Salt Lake City, Boise, San Framcisco, Helena and destroyers.

Kako 10.8.1942 was sunk NW off Rabaul by 3 torpedoes from US submarine S44.

Many thanks to Wolfgang Stöhr for additional information on this page.