Suma-class cruiser

The two Suma class cruisers (須磨型防護巡洋艦) were protected cruisers operated by the Imperial Japanese Navy. Both participated in combat during the Russo-Japanese War and World War I.

Background
The Suma class cruisers were designed and in Japan at the Yokosuka Naval Arsenal, based on experience gained in the construction of the cruiser JAPANESE CRUISER Akitsushima. The Imperial Japanese Navy was anxious to end its dependence on foreign powers for modern warships. While more lightly armed and armored than many of its contemporaries, its small size and relatively simple design facilitated its construction and its relatively high speed made it useful for many military operations. However, perhaps more importantly, the construction of these ships gave Japanese designers and shipbuilders valuable experience that would be used to construct larger and more powerful vessels in the future.

Design
The design for Suma-class was based on an all-steel, double-bottomed hull, with an armored deck, divided underneath by watertight bulkheads. Her armor covered only vital areas, such as the boilers, gun magazines and critical machinery, with a thickness of 25 mm on the deck. Her main battery consisted of two QF 6 inch /40 naval guns, one set in the forecastle and one in the stern. The main guns had a range of up to 9100 m with a nominal firing rate of 5.7 shots/minute. Secondary armament consisted of six QF 4.7 inch Gun Mk I–IV mounted in sponsons on the upper deck. These guns had a range of up to 9000 m with a nominal firing rate of 12 shots/minute. She also had ten QF 3 pounder Hotchkiss guns, with a range of up to 6000 m with a nominal firing rate of 20 shots/minute, mounted four on the upper deck, two on the poop, two on the after bridge and one each on the bow and stern, as well as four 1-inch Nordenfelt gun, which was later replaced by four 7.62 mm Maxim machine guns. She also was equipped with two 356-mm torpedoes, mounted on the deck.

The Suma class cruisers were smaller than the Akitsushima, and consequently had lighter weaponry (two six-inch guns instead of four); however, design lessons learned with the Akitsushima (such as the need to locate the secondary battery lower to the center of gravity to improve stability were implemented. Nevertheless, as with most Japanese designs of the period, the design remained top-heavy and had issues with seaworthiness and stability.

The second ship of the class, Akashi differed from Suma in that its torpedo launch tubes were moved from the bow to the rear of the ship, and the fighting top was eliminated from the mast, resulting in a sleeker, “more modern” design.

Propulsion was by two vertical triple steam reciprocating engines, 2-shafts, with 8 boilers, yielding a speed of 20 kn and a range of 11000 nmi at 10 kn based on its capacity for 544 tons of coal.

Ships in class


Ordered in 1891, launched 9 March 1895, and completed 12 December 1896, Suma served in the Boxer Rebellion and in the Russo-Japanese War. She also served patrol duty during World War I primarily in the Southeast Asia theater. She was removed from the navy list on 4 April 1923, and scrapped in 1928.
 * JAPANESE CRUISER Suma

Ordered in 1893, launched in 1897 and completed 30 March 1899, Akashi was plagued in its early career with numerous problems with its engines, especially its boilers. Once these issues were resolved, she served in the Boxer Rebellion and in the Russo-Japanese War. In World War I, Akashi served in the Battle of Tsingtao, and subsequently patrolled the sea lanes in Southeast Asia and the Mediterranean Sea. She was based out of Malta as flagship of a destroyer group as part of Japan’s assistance to the Royal Navy under the Anglo-Japanese Alliance. She was expended as a target for dive bombers south of Izu Ōshima on 3 August 1930.
 * JAPANESE CRUISER Akashi