french ironclad french ironclad wooden class ironclads built french_navy ships class classified armoured frigates single gun deck traditional disposition guns length hull meant broadside ironclads ironclad cross atlantic support french intervention mexico ship active franco prussian war saw action timber hull quickly condemned subsequently scrapped design description designed french naval architect ships class intended fight line battle unlike british ironclads ship metres long beam metres maximum draft metres depth hold metres displaced tonnes long tons ships class high metacentric height metres consequently rolled badly gun ports metres waterline proved wet single horizontal return connecting rod compound steam engine drove propeller engine powered oval boilers designed capacity indicated horsepower carried maximum tonnes long tons coal allowed steam kilometres speed knots mph class ships initially fitted light rig masts sail area square metres later changed ship rig square metres later reduced excessive rolling class ships armed modèle millimetre rifled muzzle loading guns positioned single gun deck broadside remaining guns placed upper deck chase guns fired kilogram shell muzzle velocity metres second proved ineffective armour replaced rifled breech loading modèle guns millimetre guns mounted centre gun deck pair millimetre guns replaced original chase guns wooden hull completely armoured wrought iron plates millimetres thick backed millimetre sides hull armour extended metres waterline metres class ships open topped conning tower armour millimetres thick millimetres armour underneath wooden upper deck construction service named province normandy ordered september months sisters ship laid arsenal september launched march completed july ironclad cross atlantic flagship vice admiral way support french intervention mexico forced return april outbreak yellow fever killed captain assigned mediterranean_fleet ship port visit august brest fleet hosted days later french fleet visit portsmouth hosted channel_fleet assigned commanded ship assigned ironclad squadron commanded franco prussian war saw action built timber poor shape war decommissioned june condemned august ship subsequently broken engine installed monitor
French ironclad Normandie