"Casemate ship" was an alternative term for "central battery ship" (UK) or "center battery ship" (US). The casemate (or central battery) was an armoured box that extended the full width of the ship protecting many guns. The armoured sides of the box were the sides of hull of the ship. There was an armoured bulkhead at the front and rear of the casemate, and a thick deck protecting the top. The lower edge of the casemate sat on top of ship's belt armour. Some ships, such as (laid down 1873), had a two-storey casemate.