Somerset, supporting the construction of a turret ship. In January 1862, the Admiralty agreed to construct a ship, HMS Prince Albert which had four turrets and a low freeboard, intended only for coastal defence. While Coles designed the turrets, the ship was the responsibility of Chief Constructor Isaac Watts. Another ship using Coles' turret designs, , was completed in August 1864. Its existing broadside guns were replaced with four turrets on a flat deck and the ship was fitted with of armour in a belt around the waterline. Early ships like the Royal Sovereign had little sea-keeping qualities being limited to coastal waters. Sir Edward James Reed, went on to design and build HMS Monarch, the first seagoing warship to carry her guns in turrets. Laid down in 1866 and completed in June 1869, it carried two turrets, although the inclusion of a forecastle and poop prevented the turret guns firing fore and aft. United States: USS Monitor The gun turret was independently invented by the Swedish inventor John Ericsson in America, while technologically inferior to Coles's version. Ericsson designed in 1861, its most prominent feature being a large cylindrical gun turret mounted amidships above the low-freeboard upper hull, also called the "raft". This extended well past the sides of the lower, more traditionally shaped hull. A small armoured pilot house was fitted on the upper deck towards the bow; however, its position prevented Monitor from firing her guns straight forward. Like Coles's, one of Ericsson's goals in designing the ship was to present the smallest possible target to enemy gunfire. The turret's rounded shape helped to deflect cannon shot. A pair of donkey engines rotated the turret through a set of gears; a full rotation was made in 22.5 seconds during testing on 9 February 1862 but fine control of the turret proved to be difficult as the engine would have to be placed in reverse if the turret overshot its mark or another full rotation could be made. Including the guns, the turret weighed approximately ; the entire weight rested on an iron spindle that had to be jacked up using a wedge before the turret was free to rotate. The spindle was in diameter which gave it ten times the strength needed in preventing the turret from sliding sideways. When not in use, the turret rested on a brass ring on the deck that was intended to