French ship Impérial (1856)

The Algésiras-class ships were repeats of the pioneering ship of the line Napoléon and were also designed by naval architect Henri Dupuy de Lôme. They had a length at the waterline of 71.23 metres (233 ft 8 in), a beam of 16.8 metres (55 ft 1 in) and a depth of hold of 8.16 metres (26 ft 9 in). The ships displaced 5,121 tonnes (5,040 long tons) and had a draught of 8.45 metres (27 ft 9 in) at deep load. Their crew numbered 913 officers and ratings.[1]

The primary difference between Napoléon and the Algésiras class was that the boilers of the latter ships were moved forward of the engines. They were powered by a pair of four-cylinder horizontal-return connecting-rod steam engines that drove the single propeller shaft using steam provided by eight boilers.[1] The engines were rated at 900 nominal horsepower and produced 3,603 metric horsepower (2,650 kW) for a speed of 13 knots (24 km/h; 15 mph).[2] The ships were fitted with three masts and ship rigged.[1]

The armament of the Algésiras-class ships consisted of eighteen 36-pounder (174.8 mm (6.9 in)) smoothbore cannon and sixteen 223.3 mm (8.8 in) Paixhans guns on the lower gundeck and thirty-four 30-pounder 164.7 mm (6.5 in) cannon on the upper gundeck. On the quarterdeck and forecastle were twenty 163 mm (6.4 in) Paixhans guns and a pair of 163 mm rifled muzzle-loading guns.[1]

Impérial took part in the Second Italian War of Independence and the Second French intervention in Mexico. She was renamed Jupiter in 1870, used as a barracks ship,[2] and eventually broken up in 1897.[3]