Gromoboi (, meaning: "Thunderer") was an armoured cruiser built for the Imperial Russian Navy in the late 1890s. She was designed as a long-range commerce raider and served as such during the Russo-Japanese War of 1904–05. When the war broke out, she was based in Vladivostok and made several sorties in search of Japanese shipping in the conflict's early months without much success.
Gromoboi, with the other armoured cruisers of the Vladivostok Cruiser Squadron, attempted to rendezvous in the Strait of Tsushima with the main portion of the Russian Pacific Fleet sailing from Port Arthur in August 1904. The Fleet was delayed, and the squadron returned to port alone. On the return, the squadron encountered a Japanese squadron of four armoured cruisers blocking their passage to base. The Japanese sank the oldest Russian ship, , and damaged Gromoboi and during the subsequent Battle off Ulsan. Both Russian ships were repaired within two months. Gromoboi ran aground immediately after completing her repairs and was out of action for four months. Three months after the damage from the grounding incident was repaired, she struck a mine, but successfully returned to port. Her armament was reinforced while under repair, but she saw no further action during the war.
Gromoboi was transferred to the Russian Baltic Fleet after the end of the war and began a lengthy refit that was completed in 1911. She was mostly inactive during World War I, but had her armament and protection upgraded during the war. She was placed into reserve in 1918 and sold to a German company in 1922 for scrapping. She was forced aground near Liepāja during a storm en route to Germany and was scrapped in place.
Design and description Gromoboi was originally intended to be a repeat of , but a design modification for thicker armour and improved engines made that unfeasible. The use of Rossias hull design meant that the ships looked alike.McLaughlin, p. 55
Gromoboi was long overall. She had a maximum beam of and a draught of . The ship displaced , only more than designed. She was sheathed in wood and copper to reduce biofouling.McLaughlin, pp. 55, 74 As completed Gromoboi trimmed badly by the bow, which reduced her speed and made her very wet forward. Loads had to be shifted aft and ballast added to the rear of the ship to correct her trim, but she was regarded as a good sea boat afterward with an easy, although rapid, roll.McLaughlin, p. 60
Propulsion Gromoboi dispensed with Rossias cruising engine on the centre shaft. Three equally powerful vertical triple expansion steam engines were used with a designed total of , but they developed on trials and drove the ship to a maximum speed of . Thirty-two Belleville water-tube boilers provided steam for the engines. She could carry a maximum of of coal. This gave her a radius of action of at .
Armament Gromobois main armament consisted of four 45-calibre Pattern 1892 guns; the forward pair was mounted in casemates above the forward main-deck gun's casemate. The two rear guns were situated in sponsons abreast the mizzenmast, protected by gun shields.Watts, p. 93 The guns could be depressed to −5° and elevated to 18°. They fired projectiles at a muzzle velocity of which gave a range of at 13° elevation.
Her secondary armament consisted of sixteen /45 Pattern 1892 guns. One gun was mounted under the forecastle and another in the stern; neither gun could fire to the side. Most of the remaining guns were mounted in casemates, the forward pair in front of the eight-inch guns on the upper deck and the rest on the main deck. One pair was mounted on the upper deck protected by gun shields.Brook, p. 38 In their pivot mounts the guns could depress to -6° and elevate to +20°. They fired Pattern 1907 high explosive projectiles at a muzzle velocity of . This gave a range of at maximum elevation. 240 rounds per gun were carried by Gromoboi.
Defence against torpedo boats was provided by a variety of light-calibre weapons. Gromoboi had 24 Canet Pattern 1892 50-caliber guns mounted in sponsons on the upper deck, protected by gun shields. The gun fired shells to a range of about at its maximum elevation of 21° with a muzzle velocity of . The rate of fire was between twelve and fifteen rounds per minute.
The ship carried twelve Hotchkiss guns. They fired a shell at a muzzle velocity of at a rate of 20 rounds per minute to a range of . The ship also carried 18 Hotchkiss guns. These fired a shell at a muzzle velocity of at a rate of 20 rounds per minute to a range of .
Gromoboi also had four submerged torpedo tubes, with two mounted on each broadside.
Armour The Naval Ministry had hoped to increase the Gromobois armour thickness and increase the armour protection of the armament, but still use Rossia hull design. The Ministry also hoped to use the new, more resistant Krupp armour, but Russian plants had proven unable to manufacture it when it was ordered and Harvey armour was used instead.Sources differ on the type of armour actually used. Brook, Gardiner and Grey, and Watts all state that Krupp cemented armour was used. In fact, for Gromoboi, the waterline belt was reduced in thickness by from the older ship to six inches to better protect her guns. The belt was shortened by in length to only . It was reduced in height by as well to a total of ; it extended above the waterline and below the waterline. The belt was closed off by six-inch bulkheads fore and aft.Campbell, p. 190
Gromobois casemates were thick, with two-inch backs and roofs. The two-inch thick transverse bulkhead fore and aft protected them from raking fire. The armour deck was 1.5 inches thick on the flat and thick where it sloped down to meet the belt. The protective deck extended fore and aft of the armour deck and ranged from in thickness. The change in the machinery allowed Gromoboi to dispense with Rossias glacis armour that had been necessary to protect the tops of the engine cylinders. The conning tower had walls thick, made of Krupp armour. The funnel uptakes and ammunition hoists were protected by 1.5 inches of armour between the lower and middle decks.
Service Gromoboi was built by the Baltic Works in Saint Petersburg. Construction began on 14 June 1897, although she was not formally laid down until 7 May 1898, and the ship was launched on 8 May 1899. She was transferred to Kronstadt on 24 November 1899 to finish fitting out, but was forced aground by sea ice. She was freed three days later, but needed repairs to her sheathing. She left Liepāja on 10 December 1900 en route to the Far East and stopped briefly at Kiel, where she was inspected by Prince Henry of Prussia, and at Plymouth where the officers visited the Devonport naval base. She represented Russia at the granting of the constitution to Australia, visiting Sydney and Melbourne in April–May 1901, before visiting Nagasaki in July. Gromoboi finally reached Port Arthur on 29 July 1901. She remained in the Pacific until the beginning of the Russo-Japanese War in 1904.McLaughlin, p. 77 During this voyage she was commanded by Karl Petrovich Jessen.
Russo-Japanese War
By this time, Gromoboi was assigned of the Vladivostok Cruiser Squadron under the command of Rear Admiral Karl Jessen. The other ships were the armoured cruisers Rossia and as well as the protected cruiser . The squadron made a number of sorties against Japanese shipping early in the war. Only one was reasonably successful: on June 15, 1904 the squadron sank Hitachi Maru, which was carrying eighteen siege howitzers and over 1000 troops intended for the siege of Port Arthur.Brook, p. 34
Battle off Ulsan
During the war the bulk of the Russian Pacific Fleet was located in Port Arthur where it was blockaded by the Japanese. On 10 August, the ships at Port Arthur attempted breakout to Vladivostok, but were turned back in the Battle of the Yellow Sea. Admiral Jessen was ordered to rendezvous with them, but the order was delayed. His ships had to raise steam, so he did not sortie until the evening of 13 August. Bogatyr had been damaged earlier when she grounded and did not sail with the squadron. By dawn he had reached the island of Tsushima in the Tsushima Strait between Korea and Japan. He turned back for Vladivostok when he failed to see any ships from the Port Arthur squadron. north of the island he encountered the Japanese squadron commanded by Vice Admiral Kamimura Hikonojō tasked to patrol the Tsushima Strait. The Japanese force had four modern armoured cruisers, , , , and . 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, pp. 34, 37
Jessen turned 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, 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. Iwate was hit around this time, which knocked out three 6-inch and one 12-pounder guns, killing 32 and wounding 43. The Japanese squadron opened the range again when it made a 180° another turn to port. 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, p. 43
About this time Kamimura's two elderly protected cruisers, and , were approaching from the south. Their arrival allowed Kamimura to pursue Jessen with all of his armoured cruisers while the two new arrivals dealt with Rurik. They fought a running battle with the Russians for the next hour and a half; scoring enough hits on them to force their speed down to . Azumas engines again broke down during this chase and she was replaced in the line by Tokiwa. The Japanese closed to a minimum of about , but Kamimura then opened the range up to .