Japanese Heavy Cruiser Takao 1937–1946

Takao 1932–1937
The heavy cruiser Takao entered service with the Japanese Imperial Navy on May 3, 1932. She was a very intriguing warship, the first of her class which also included Atago, Maya and Chokai.

After my extensive Takao monograph had been published by Conway M. P. in 1994, one of the Royal Navy reviewers wrote: “Now everybody can see how different the Japanese cruisers were from anything designed elsewhere – as if they had been built by another (alien) civilization”.
In a sense the rise of the heavy cruisers was made possible by the outcome of the Washington Naval Conference (November 12, 1921 – February 6, 1922), which green-lighted the development of lighter surface units under 10 000 tons standard displacement. As one of the Conference’s participants, Japan was allowed to build twelve A class cruisers by 1932, which later became known as heavy cruisers due to their strong armament and armor protection.

Takao in trials off Tatayama on 31 March 1932. On this day she reached her maximum speed of 35,6 knots at 12 175 tons displacement. [Colorization of old black & white photos Janusz Skulski]

Along with her sister ships, the Takao was the final word in the design of warships of that class (the plans to build three “improved Takao type” vessels, followed by four more, were shelved after the London Conference of April 1922). Although the Takao was supposed to be a “treaty cruiser” with the displacement capped at 10 000 tons, she was already 4 000 tons above that limit at the time of launching. The refits in 1937 and 1939 further increased the warship’s displacement to 16 000 and then to 17 000 tons.
The history of the new generation of the IJN cruisers, featuring a completely new hull design, new types of armament, propulsion system and fire control, began in earnest in October 1921 when the Navy’s General Staff approved the construction of an “experimental” cruiser designed by Vice Admiral Yozuru Hiraga and his assistant Kikuo Fujimoto. Yozuru Hiraga had already made his mark as the naval architect with the design of the Naka class light cruisers,
The new cruiser was named Yubari and featured armor integrated into the hull structure, which added complexity to the process of the ship’s construction, but also offered substantial weight savings. Hiraga and Fujimoto used the lessons learned from the construction of the Yubari to build eight class A cruisers under the provisions of the “Eight-Eight Fleet Program of 1921–1929”. Among those were two Kako class warships (Kako and Furutaka), two Aoba class vessels (Aoba and Kinugasa) and four Myoko class cruisers (Myoko, Ashigara, Haguro and Nachi). Each of those “quadruplets” was refined and improved using the lessons learned from the construction of their predecessors.
In March 1927 the Imperial Navy General Staff authorized the fleet expansion plan for 1927–1931, which included the construction of additional four heavy cruisers, euphemistically referred to as “improved Myoko class”. That was clearly an understatement since compared to the Myoko the design of the new warships incorporated a number of radical changes.

Takao tower bridge structure as completed, August 1932 – perspective and front elevation. [Drawings  by Janusz Skulski]

The work on the new design began in early 1925 under the direction of Kikuo Fujimoto, who by that time had been promoted to the rank of Commander. The finished project was approved by Admiral Hiraga after his return from Great Britain. The new cruiser, similarly to the earlier Myoko class vessels, was to be superior in every respect to the heavy cruisers in service with the potential enemies – the USN and the Royal Navy. The new warship was to have standard displacement of 11 531 tons and full combat displacement of 12 985 tons, which exceeded the Washington Conference limitations by almost 3 000 tons. When the ship was commissioned her full combat displacement grew further to 14 365 tons due to the design changes and improvements introduced at the construction stage. Thus the new warship ended up 10 percent heavier than planned, despite the implementation of innovative construction techniques designed to reduce the ship weight, such as electric arc welding or the use of aluminum. The overweight condition led to the reduction of the ship’s metacentric height, top speed and freeboard. Efforts were made during the 1937 and 1939 refits to address those significant issues.