was the lead ship of her class of armored cruisers (Sōkō jun'yōkan) built for the Imperial Japanese Navy (IJN) in the late 1890s. As Japan lacked the industrial capacity to build such warships itself, the ship was built in Britain. She often served as a flagship and participated in most of the naval battles of the Russo-Japanese War of 1904–1905. The ship was lightly damaged during the Battle off Ulsan and the Battle of Tsushima. Izumo was ordered to protect Japanese citizens and interests in 1913 during the Mexican Revolution and was still there when World War I began in 1914.
She was then tasked to search for German commerce raiders and protect Allied shipping off the western coasts of North and Central America. The ship assisted the armored cruiser in early 1915 when she struck a rock off Baja California. In 1917, Izumo became the flagship of the Japanese squadron deployed in the Mediterranean Sea. After the war, she sailed to Great Britain to take control of some ex-German submarines and then escorted them part of the way back to Japan.
The ship spent most of the 1920s as a training ship for naval cadets and became flagship of the IJN's China forces in 1932 during the First Shanghai Incident. Izumo participated in the Battle of Shanghai five years later and was not damaged, despite repeated aerial attacks. The ship played a minor role in the Pacific War, supporting Japanese forces during Philippines Campaign until she struck a mine. She returned to Japan in 1943 and again became a training ship for naval cadets. Izumo was sunk by American carrier aircraft during the attack on Kure in July 1945. Her wreck was refloated and scrapped in 1947.
Background and description The 1896 Naval Expansion Plan was made after the First Sino-Japanese War and included four armored cruisers in addition to four more battleships, all of which had to be ordered from British shipyards as Japan lacked the capability to build them itself. Further consideration of the Russian building program caused the IJN to believe that the battleships ordered under the original plan would not be sufficient to counter the Imperial Russian Navy. Budgetary limitations prevented ordering more battleships and the IJN decided to expand the number of more affordable armored cruisers to be ordered from four to six ships. The revised plan is commonly known as the "Six-Six Fleet".Evans & Peattie, pp. 57–62 Unlike most of their contemporaries which were designed for commerce raiding or to defend colonies and trade routes, Izumo and her half-sisters were intended as fleet scouts and to be employed in the battleline.Milanovich, p. 72
The ship was long overall and between perpendiculars. She had a beam of and had an average draft of . Izumo displaced at normal load and at deep load. The ship had a metacentric height of .Milanovich, pp. 74, 80 Her crew consisted of 672 officers and enlisted men.Jentschura, Jung & Mickel, p. 74
Izumo had two 4-cylinder triple-expansion steam engines, each driving a single propeller shaft.Milanovich, p. 81 Steam for the engines was provided by 24 Belleville boilers and the engines were rated at a total of . The ship had a designed speed of and reached during her sea trials from . She carried up to of coalBrook 1999, p. 112 and could steam for at a speed of .
The main armament for all of the "Six-Six Fleet" armored cruisers was four eight-inch guns in twin-gun turrets fore and aft of the superstructure. The secondary armament consisted of 14 Elswick Ordnance Company "Pattern Z" quick-firing (QF), guns. Only four of these guns were not mounted in armored casemates on the main and upper decks and their mounts on the upper deck were protected by gun shields. Izumo was also equipped with a dozen QF 12-pounder 12-cwt guns"Cwt" is the abbreviation for hundredweight, 12 cwt referring to the weight of the gun. and eight QF 2.5-pounder Yamauchi guns as close-range defense against torpedo boats. The ship was equipped with four submerged torpedo tubes, two on each broadside.Milanovich, p. 78
All of the "Six-Six Fleet" armored cruisers used the same armor scheme with some minor differences. The waterline belt of Krupp cemented armor ran the full length of the ship and its thickness varied from amidships to at the bow and stern. It had a height of , of which was normally underwater. The upper strake of belt armor was thick and extended from the upper edge of the waterline belt to the main deck. It extended from the forward to the rear barbette. The Izumo class had oblique 127 mm armored bulkheads that closed off the ends of the central armored citadel.Milanovich, pp. 80–81
The barbettes, gun turrets and the front of the casemates were all 6 inches thick while the sides and rear of the casemates were protected by of armor. The deck was thick and the armor protecting the conning tower was in thickness.Chesneau & Kolesnik, p. 225
Construction and career
The contract for Izumo, named after the eponymous province,Silverstone, p. 331 was signed on 24 September 1897 with Armstrong Whitworth. The ship was laid down at their shipyard in Elswick on 14 May 1899 and launched on 19 September. She was completed on 25 September 1900 and departed for Japan on 2 OctoberMilanovich, p. 73 under the command of Captain , who had been appointed to supervise her construction and bring her back to Japan on 29 September 1899. Izumo arrived in Yokosuka on 8 December and Inoue was confirmed in his command.Hackett & Kingsepp
Russo-Japanese War At the start of the Russo-Japanese War, Izumo, now under the command of Captain Miyaoka Naoki, was the flagship of Vice Admiral Kamimura Hikonojō, commander of the 2nd Fleet.Kowner, p. 465 She participated in the Battle of Port Arthur on 9 February 1904, when Vice Admiral Tōgō Heihachirō led the Combined Fleet in an attack on the Russian ships of the Pacific Squadron anchored just outside Port Arthur. Tōgō had expected the surprise night attack by his destroyers to be much more successful than it was, anticipating that the Russians would be badly disorganized and weakened, but they had recovered from their surprise and were ready for his attack. The Japanese ships were spotted by the protected cruiser , which was patrolling offshore and alerted the Russians. Tōgō chose to attack the Russian coastal defenses with his main armament and engage the ships with his secondary guns. Splitting his fire proved to be a poor decision as the Japanese eight- and six-inch guns inflicted little damage on the Russian ships, which concentrated all their fire on the Japanese ships with some effect.Forczyk, pp. 42–43 Although many ships on both sides were hit, Russian casualties numbered some 150, while the Japanese suffered roughly 90 killed and wounded before Tōgō disengaged.Corbett, I, p. 105
In early March, Kamimura was tasked to take the reinforced 2nd Division north and make a diversion off Vladivostok. While scouting for Russian ships in the area, the Japanese cruisers bombarded the harbor and defenses of Vladivostok on 6 March to little effect. Upon their return to Japan a few days later, the 2nd Division was ordered to escort the transports ferrying the Imperial Guards Division to Korea and then to join the ships blockading Port Arthur. Kamimura was ordered north in mid-April to cover the Sea of Japan and defend the Korea Strait against any attempt by the Vladivostok Independent Cruiser Squadron, under the command of Rear Admiral Karl Jessen, to break through and unite with the Pacific Squadron. The two units narrowly missed each other on the 24th in heavy fog and the Japanese proceeded to Vladivostok where they laid several minefields before arriving back at Wonsan on the 30th.Corbett, I, pp. 138–39, 142–45, 160, 177, 188–89, 191–96
The division failed to intercept the Russian squadron as it attacked several transports south of Okinoshima Island on 15 June due to heavy rain and fog. The Russians sortied again on 30 June and Kamimura finally was able to intercept them the next day near Okinoshima. The light was failing when they were spotted and the Russians were able to disengage in the darkness. Jessen's ships sortied again on 17 July headed for the eastern coast of Japan to act as a diversion and pull Japanese forces out of the Sea of Japan and the Yellow Sea. The Russian ships passed through Tsugaru Strait two days later and began capturing ships bound for Japan. The arrival of the Russians off Tokyo Bay on the 24th caused the Naval General Staff to order Kamimura to sail for Cape Toi Misaki, Kyūshū, fearing that Jessen would circumnavigate Japan to reach Port Arthur. Two days later he was ordered north to the Kii Channel and then to Tokyo Bay on the 28th. The General Staff finally ordered him back to Tsushima Island on the 30th; later that day he received word that Jessen's ships had passed through the Tsugaru Strait early that morning and reached Vladivostok on 1 August.Corbett, I, pp. 283–89, 319–25, 337–51
Battle off Ulsan
On 10 August, the ships at Port Arthur attempted a breakout to Vladivostok, but were turned back in the Battle of the Yellow Sea. Jessen was ordered to rendezvous with them, but the order was delayed. His three armored cruisers, , , and , had to raise steam, so he did not sortie until the evening of 13 August. By dawn he had reached Tsushima, but turned back when he failed to see any ships from the Port Arthur squadron. north of the island he encountered Kamimura's squadron, which consisted of four modern armored cruisers, , , , and Izumo. The two squadrons had passed during the night without spotting one another and each had reversed course around first light. This put the Japanese ships astride the Russian route to Vladivostok.Brook 2000, pp. 34, 37
Jessen ordered his ships to turn to the northeast when he spotted the Japanese at 05:00 and they followed suit, albeit on a slightly converging course. Both sides opened fire around 05:23 at a range of . The Japanese ships concentrated their fire on Rurik, the rear ship of the Russian formation. She was hit fairly quickly and began to fall astern of the other two ships. Jessen turned southeast in an attempt to open the range, but this blinded the Russian gunners with the rising sun and prevented any of their broadside guns from bearing on the Japanese. About 06:00, Jessen turned 180° to starboard in an attempt to reach the Korean coast and to allow Rurik to rejoin the squadron. Kamimura followed suit around 06:10, but turned to port, which opened the range between the squadrons. Azuma then developed engine problems and the Japanese squadron slowed to conform with her best speed. Firing recommenced at 06:24 and Rurik was hit three times in the stern, flooding her steering compartment; she had to be steered with her engines. Her speed continued to decrease, further exposing her to Japanese fire, and her steering jammed to port around 06:40.Brook 2000, pp. 39, 43
Jessen made another 180° turn in an attempt to interpose his two ships between the Japanese and Rurik, but the latter ship suddenly turn to starboard and increased speed and passed between Jessen's ships and the Japanese. Kamimura turned 180° as well so that both squadrons were heading southeast on parallel courses, but Jessen quickly made another 180° turn so that they headed on opposing courses. The Russians reversed course for the third time around 07:45 in another attempt to support Rurik although Rossia was on fire herself; her fires were extinguished about twenty minutes later. Kamimura circled Rurik to the south at 08:00 and allowed the other two Russian ships to get to his north and gave them an uncontested route to Vladivostok. Despite this, Jessen turned back once more at 08:15 and ordered Rurik to make her own way back to Vladivostok before turning north at his maximum speed, about .Brook 2000, p. 43