The casemate ironclad was a type of iron or iron-armored gunboat briefly used in the American Civil War by both the Confederate States Navy and the Union Navy. Unlike a monitor-type ironclad which carried its armament encased in a separate armored gun deck/turret, it exhibited a single casemate structure, or armored citadel, on the main deck housing the entire gun battery. As the guns were carried on the top of the ship yet still fired through fixed gunports, the casemate ironclad is seen as an intermediate stage between the traditional broadside frigate and modern warships.
CSS Palmetto State, the archetypal casemate ironclad. Note the sloped deck and the low waterline.
Detail of the remains of USS Cairo as a museum ship today. The sloped casemate deck is clearly visible.
Casemate Ironclad USS Cairo on a contemporary photograph.
A monitor is a relatively small warship that is neither fast nor strongly armored but carries disproportionately large guns. They were used by some navies from the 1860s, during the First World War and with limited use in the Second World War.
USS Monitor, the first monitor (1861)
HMS Marshal Ney used a surplus 15-inch gun battleship turret.
Officers of a Union monitor, probably USS Sangamon, photographed during the American Civil War
Huáscar anchored in the harbour at Talcahuano
