The Kōtetsu, later renamed Azuma, was the first ironclad warship of the Imperial Japanese Navy, notable for its role in Japan’s naval modernization and the pivotal conflicts during the Meiji Restoration. Originally built in Bordeaux, France, under the cover name Sphinx, she was designed as an armored ram intended for shallow waters, with a length of approximately 186 feet 9 inches (56.9 meters) overall, including her prominent pointed ram. Her hull was a composite construction sheathed in copper to prevent biofouling, featuring a pronounced tumblehome and a displacement of 1,390 long tons (1,410 tons). She had a beam of 32 feet 6 inches (9.9 meters) and a draught of 14 feet 3 inches (4.3 meters). Her propulsion system consisted of twin Mazeline horizontal two-cylinder steam engines, driving four-bladed screws, which delivered a maximum speed of about 10.8 knots during sea trials. The vessel was armed with a single 10-inch (254 mm) Armstrong rifled muzzle-loading gun in a bow turret, complemented by two 6.4-inch (70-pounder) guns in a secondary turret abaft the mainmast, along with additional smaller guns including 6-pounders, 4-pounders, and a Gatling gun. Her armor comprised a wrought-iron belt extending over 2 meters below water, backed by teak, with thicknesses ranging from 9 to 12 centimeters (3.5 to 4.7 inches). The armored turrets protected her main guns, with the bow turret armored with 4.5 inches of steel. Her power plant, rated at around 1,200 horsepower, allowed her to reach a top speed of 10.8 knots. She had an estimated operational range of 3,000 nautical miles, suitable for extended coastal operations. Originally built for the Confederate States Navy during the American Civil War, she was sold to Denmark, then to the Confederacy, before being captured by the United States. In 1867, she was purchased by Japan, where she played a critical role in the Boshin War, notably during the Naval Battle of Hakodate Bay. After the war, she was renamed Azuma, serving in various roles including patrol and guard duties, until she was stricken in 1888 and sold for scrap in 1889. Her armor was repurposed for electrical generators in Tokyo, marking her lasting contribution to Japan’s naval and industrial development.

This description has been generated using GPT-4.1-NANO based on the Vessel's wikidata information and then modified by ShipIndex.org staff.