Bayan-class cruiser

Class of Russian armored cruisers

The Bayan class was a group of four armored cruisers built for the Imperial Russian Navy around the beginning of the 20th century. Two of the ships were built in France, as Russian shipyards had no spare capacity. The lead ship, Russian cruiser Bayan, was built several years earlier than the later three. The ship participated in several of the early naval battles of the Russo Japanese War of 1904–05, and provided naval gunfire support for the Imperial Russian Army until she struck a mine. Bayan was trapped in harbor during the subsequent Siege of Port Arthur, and was sunk by Japanese artillery. She was salvaged and put into service with the Imperial Japanese Navy with the name of Aso. She mostly served as a training ship before she was converted into a minelayer in 1920. The ship was sunk as a target in 1932. Her three sisters were all assigned to the Baltic Fleet. Russian cruiser Pallada was the first ship lost by the Russians during World War I when she was sunk by a German submarine in October 1914. The two surviving ships were modified to lay mines, and participated in the Battle of Åland Islands in 1915 and the German invasion of the Estonian islands in 1917. They were decommissioned in 1918 and sold for scrap in 1922.

The Bayan class marked a departure from the previous Russian armored cruisers, as they were smaller ships designed to serve as scouts for the fleet rather than as commerce raiders. Authorized in the 1896–1902 building program, the design was outsourced to a French shipyard, Forges et Chantiers de la Méditerranée, because Russian shipyards were already at full capacity. Negotiations began in March 1897, and a contract was signed in May 1898 for one ship with delivery in 36 months. The Navy was reasonably pleased with the first ship, Bayan, and decided to order another cruiser after the start of the Russo Japanese War in February 1904. Russian shipyards were still unavailable, so the Navy decided to simply order a repeat with minor modifications based on war experience. This was an attempt to minimize the work load on the Naval Technical Committee (Morskoi tekhnicheskii komitet), but they proved to require more attention than planned and a contract was not signed until 20 April 1905. The contract specified that all drawings would be turned over to allow for the construction of two identical ships in St. Petersburg, using newly available slipways. These changes generally added weight and the armor was reduced in thickness to compensate, although the change from Harvey armor to more resistant Krupp armor meant that there was little actual loss in protection.

The Bayan class ships were 449 feet (137 m) long overall and 443 feet (135 m) between perpendiculars. They had a maximum beam of 57 feet (17 m), a draft of 22 feet (7 m) and displaced The ships had a crew of 573 officers and men. They had two vertical triple expansion steam engines, each driving a single propeller shaft, using steam provided by 26 Belleville boilers. Designed for a total of intended to propel the cruisers at , The ships' eight 45 caliber Canet Model 1891 quick firing (QF) guns were mounted in casemates on the sides of the ship's hull. They fired shells that weighed with a muzzle velocity of They had a range of when fired at an elevation of +20°. A number of smaller guns were carried for close range defense against torpedo boats. These included twenty 50 caliber Canet Model 1891 QF guns. Eight of these were mounted in casemates in the side of the hull and in the superstructure. The remaining guns were located above the 6 inch gun casemates in pivot mounts with gun shields. The gun fired shells to a range of about , at an elevation of +20° degrees with a muzzle velocity of The Bayan class also mounted eight (Bayan) or four Hotchkiss guns in the three later ships. In addition, Bayan was fitted with two Hotchkiss guns

Bayan was equipped with two submerged torpedo tubes, one on each broadside, while those of the three later ships were in size.