Firepower was provided by a large number of guns, each of which could traverse only in a limited arc. Due to stability issues, fewer large (and thus heavy) guns can be carried high on a ship, but as this set casemates low and thus near the waterline they were vulnerable to flooding, effectively restricted their use to calm seas. Additionally casemate mounts had to be recessed into the side of a vessel to afford a wide arc of fire, and such recesses presented shot traps, compromising the integrity of armour plating. Rotating turrets were weapon mounts designed to protect the crew and mechanism of the artillery piece and with the capability of being aimed and fired over a broad arc, typically between a three-quarter circle up to and including a full 360 degrees. These presented the opportunity to concentrate firepower in fewer, better-sited positions by eliminating redundancy, in other words combining the firepower of those guns unable to engage an enemy because they sited on the wrong beam into a more powerful, and more versatile unified battery. History Designs for a rotating gun turret date back to the late 18th century. In the mid 19th century, during the Crimean War, Captain Cowper Phipps Coles constructed a raft with guns protected by a 'cupola' and used the raft, named the Lady Nancy, to shell the Russian town of Taganrog in the Black Sea during the Siege of Taganrog. The Lady Nancy "proved a great success" and Coles patented his rotating turret design after the war. UK: first designs The British Admiralty ordered a prototype of Coles's patented design in 1859, which was installed in the ironclad floating battery, HMS Trusty, for trials in 1861, becoming the first warship to be fitted with a revolving gun turret. Coles's aim was to create a ship with the greatest possible all round arc of fire, as low in the water as possible to minimise the target. The Admiralty accepted the principle of the turret gun as a useful innovation, and incorporated it into other new designs. Coles submitted a design for a ship having ten domed turrets each housing two large guns. The design was rejected as impractical, although the Admiralty remained interested in turret ships and instructed its own designers to create better designs. Coles enlisted the support of Prince Albert, who wrote to the first Lord of the Admiralty, the Duke of