This platform can be mounted on a fortified building or structure such as an anti-naval land battery, or on a combat vehicle, a naval ship, or a military aircraft.
[1] Practical rotating turret warships were independently developed in Great Britain and the United States with the availability of steam power in the mid-19th Century.
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.
Its existing broadside guns were replaced with four turrets on a flat deck and the ship was fitted with 5.5 inches (140 mm) of armour in a belt around the waterline.
Coles, in collaboration with 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 deck prevented the guns firing fore and aft.
Erickson's most prominent design feature was a large cylindrical gun turret mounted amidships above the low-freeboard upper hull, also called the "raft".
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.
[6] The spindle was 9 inches (23 cm) in diameter, which gave it ten times the strength needed in preventing the turret from sliding sideways.