class monitor class ironclad monitors pair ships built german_imperial_navy aftermath franco prussian war class comprised ships built shipyard bremen armed pair bronze cannon revolving gun turret ships intended protect german border france event conflict short service lives war come served briefly defenses starting withdraw service ships sold scrap apparently december design aftermath franco prussian war imperial_german_navy decided needed build river service rhine defend german border decision came despite navy having seen french_navy negative experiences similar war german_navy decided armored necessary awarded contract design build vessels design staff based work pair monitors recently built service danube characteristics meters long waterline long overall beam cruising load monitors forward draft aft draft maximum draft forward aft ships designed partially flood combat hull upper gun turret water reduced respectively ships designed displacement metric tons long tons short tons load displaced long tons short tons hulls constructed transverse iron frames ships crew officer enlisted men carried single boat ships powered horizontal cylinder single expansion steam engines drove pair bladed screws diameter engines placed single engine room locomotive boilers apiece supplied steam engines located separate boiler room engines rated indicated horsepower speed knots mph service capable nominal horsepower mph ships slowly turned poorly especially steaming downstream handle upstream particularly turning current handling ships flooded combat especially dangerous ships armed pair centimeter bronze cannon manufactured krupp rifled muzzle loading guns mounted single revolving gun turret placed armored amidships guns fired pound shot supplied rounds ammunition ships protected combination wrought iron armor teak turret sides armored millimeters iron backed teak roofs thick conning tower thick sides thick roof protected armor plate sides service history intention use defend railway bridges rhine event french war revenge franco prussian war ships built dockyard bremen construction numbers respectively compelled contribute construction ships intended defend railway bridges company ships laid launched later year commissioned april spent year career april transferred defenses time monitors entered service prospect french attack decreased prompting navy question retaining vessels result quickly removed service ultimate fate ships unclear according naval historian ships sold gold marks december states ships remained service sold scrapping version appear correct published elevation extant time
Rhein-class monitor