Chikuma Class Cruiser - Design

Design

The basic design of the Chikuma-class cruisers was modeled after the Royal Navy Town-class with some modifications and was also largely influenced by the design of the Tone. The silhouette of the Chikuma-class was readily distinguishable due to its four smokestacks. Contrary to many popular publications, the protection of the Chikuma-class was similar to Tone-class, and they remained protected cruisers, without an armoured belt.

The Chikuma-class cruisers were the first high-speed turbine-driven cruisers in the Imperial Japanese Navy, which gave them much greater speed than previous cruiser designs. Chikuma and Hirado used the newly-developed Curtiss turbines, which gave them a rated top speed of 26 knots. During speed trials, they achieved 26.83 and 26.87 knots respectively. Yahagi was built with a Parsons-type turbine engine, and achieved 27.14 knots during speed trials. Although the class achieved its target of high speed, the new technology of the engines, especially issues with material strength and fatigue, led to maintenance issues.

In terms of armaments, the Chikuma-class was unique in its use of a single caliber main battery. The class was armed with eight Type 41 6 inch 45 caliber naval gun, one each fore and aft, and three mounted in sponsons on each side of the hull. These guns were supplemented by four QF 12 pounder 12 cwt naval guns and two Lewis guns. In addition, each vessel was equipped with three torpedo launchers with 457-mm torpedoes.

After 1919, two 8 cm/40 3rd Year Type naval gun were added for anti-aircraft defense abeam of the fourth funnel, replacing two of the 12-pdrs in Hirado and three of the 12-pdrs in Yahagi and Chikuma.