Provence-class ironclad

The Provence-class ironclads consisted of 10 ironclad frigates built for the French Navy (Marine Nationale) during the 1860s. Only one of the sister ships was built with an wrought iron hull; the others were built in wood. By 1865 they were armed with eleven 194 mm guns and played a minor role in the 1870–1871 Franco-Prussian War. The ships began to be disposed of in the early 1880s, although several lingered on in subsidiary roles for another decade before they followed their sisters to the scrap yard.

Design and description
The Provence class was designed by naval architect Henri Dupuy de Lôme as an enlarged version of the Gloire-class ironclads with thicker armor, more powerful guns, and better seakeeping qualities. The ships had an overall length of 82.9 m, a beam of 17.06 m, and a draft of 8.4 m at deep load. They displaced 5810 t. All of the ships except FRENCH IRONCLAD Héroïne had wooden hulls; that ship had an iron hull. The Provence-class ships had a metacentric height of about 4.5 ft and did not roll as badly as the Gloires. They had a crew of 579–594 officers and enlisted men.

The ships of the Provence class had a single horizontal-return connecting-rod compound steam engine that drove a four-bladed, 6.1 m propeller, using steam provided by eight boilers at a maximum pressure of 1.8 kg/cm2. The engine was rated at 1,000 nominal horsepower or 3200 PS and was intended to give the ships a speed in excess of 13 kn. Available records of their sea trials show that they achieved speeds of 13.2 - 16.5 kn from 2918 - 3895 PS. The Provence class carried between 590 - 640 t of coal which allowed them to steam for 2410 nmi at a speed of 10 kn. They were fitted with a three-masted barque rig that had a sail area of 1960 sqm.

Armament and protection
The main battery of the Provence-class ships was intended to be thirty 164.7 mm Modèle 1858–60 rifled muzzle-loading (RML) guns, but this was changed to eleven 194 mm Modèle 1864 smoothbore muzzle-loading guns in 1865. It is uncertain if any received their intended armament, although naval historian N. J. M. Campbell states that FRENCH IRONCLAD Flandre, FRENCH IRONCLAD Provence and FRENCH IRONCLAD Héroïne, three of the first ships completed, were armed with a mix of ten 164.7 mm smoothbores, twenty-two 164.7 mm RMLs and a pair of 220 mm RML howitzers. Ten of the 194 mm Modèle 1864 guns were mounted on the broadside and one was on a pivot mount below the forecastle deck as a chase gun. Three years later, their armament was changed to eight 240 mm RMLs and four 194 mm smoothbores.

From the upper deck down to below the waterline, the sides of the ships were completely armored with 150 mm of wrought iron. The sides of the battery itself were protected with 110 mm of armor. The conning tower's sides consisted of 102 mm armor plates.