The Colbert-class ships were designed by Constructor Sabattier as improved versions of the ironclad and were the last ships authorized by the 1857 Naval Program. They reverted to a single propeller shaft to improve their sailing qualities and to lessen the chance of the propellers being fouled by fallen rigging. As central battery ironclads, they had their armament concentrated amidships. Like most ironclads of their era, they were equipped with a plough-shaped ram. The ships' crew numbered 774 officers and men. Their metacentric height was low, a little above. The ships measured overall, with a beam of. They had maximum drafts of and displaced. While the exact reason for such prolonged construction time is not known, it is believed that reduction of the French Navy's budget after the Franco-Prussian War of 1870–71 and out-of-date work practices in French dockyards were likely causes.
Propulsion
The Colbert class had a single Wolf three-cylinder horizontal return connecting-rod compound steam engine that drove one propeller. The engine was powered by eight oval boilers and was designed for a capacity of. On sea trials the engines produced and the ships reached speeds of. The ships carried a maximum of of coal which allowed them to steam for approximately at a speed of. They were ship rigged with three masts and had a sail area around.
Armament
The Colberts had two guns mounted in barbettes on the upper deck, one gun at the forward corners of the battery, with six additional guns on the battery deck below the barbettes. The side of the upper deck were cut away to improve the ability of the barbette guns to bear fore and aft. One gun was mounted in the forecastle as a chase gun. The ship's secondary armament consisted of six guns, four forward of the battery and two aft. These latter two guns were replaced in 1878 by another 240-millimeter gun as a stern chaser. The ship also mounted four above-water torpedo tubes. All of the guns could fire both solid shot and explosive shells. The 18-caliber 274-millimeter Modèle 1870 gun fired an armor-piercing, shell while the gun itself weighed. The gun fired its shell at a muzzle velocity of and was credited with the ability to penetrate of wrought iron armor at the muzzle. The armor-piercing shell of the 19-caliber 240-millmeter Modèle 1870 gun weighed while the gun itself weighed. It had a muzzle velocity of and could penetrate of wrought iron armor at the muzzle. The 138-millimeter gun was 21 calibers long and weighed. It fired a explosive shell that had a muzzle velocity of. At some point the ship received fourteen to eighteen Hotchkiss 5-barrel revolving guns. They fired a shell weighing about at a muzzle velocity of about to a range of about and had a rate of fire of about 30 rounds per minute.
Armor
The Colbert-class ships had a complete wrought iron waterlinebelt that was thick amidships and tapered to at the stern. It was backed by of wood. The sides of the battery itself were armored with of wrought iron, backed by of wood, and the ends of the battery were closed by transverse armored bulkheads thick, backed by of wood. The barbettes were unarmored, but the deck was thick.
Ships
Service
Colbert served as the flagship of the Mediterranean Squadron from 1879 to 1890 when she was placed in reserve. Trident became the flagship of the second-in-command of the squadron in 1879. The sisters bombarded the port of Sfax on 15–16 July 1881 as the French occupied Tunisia, under the command of Vice AdmiralHenri Garnault. Colbert was recommissioned in 1892 before she was disarmed and paid off in 1895. Trident was disarmed and placed in reserve in 1886–89, but was recommissioned in 1889 and resumed her role as flagship until she was again placed in reserve in 1894. The ship served as a gunnery training ship until she was condemned in 1900. She was renamed Var in 1904 and was sold for scrap five years later. Colbert was also condemned in 1900 and sold for scrap in 1909.
