Gun Turret - Warships - Layout

Layout

In naval terms, turret traditionally and specifically refers to a gun mounting where the entire mass rotates as one, and has a trunk that pierces the deck. The rotating part of a turret seen above deck is the gunhouse, which protects the mechanism and crew, and is where the guns are loaded. The gunhouse is supported on a bed of rotating rollers, and is not physically attached to the ship; were the ship to capsize, the turret would fall out.

Below the gunhouse there may be a working chamber, where ammunition is handled, and the main trunk, which accommodates the shell and propellant hoists that bring ammunition up from the magazines below. There may be a combined hoist (cf the animated British turret) or separate hoists (cf the American turret cutaway). The working chamber and trunk rotate with the gunhouse, and sit inside a protective armoured barbette. The barbette extends down to the main armoured deck (red in the animation). At the base of the turret sit handing rooms, where shell and propelling charges are passed from the shell room and magazine to the hoists.

The handling equipment and hoists are complex arrangements of machinery that transport the shells and charges from the magazine into the base of the turret. Bearing in mind that shells can weigh around a ton, the hoists have to be powerful and rapid; a 15 inch turret of the type in the animation was expected to perform a complete loading and firing cycle in a minute

The loading system is fitted with a series of mechanical interlocks that ensure that there is never an open path from the gunhouse to the magazine down which an explosive flash might pass. Flash-tight doors and scuttles open and close to allow the passage between areas of the turret. Generally, with large-calibre guns, powered or assisted ramming is required to force the heavy shell and charge into the breech.

As the hoist and breech must be aligned for ramming to occur, there is generally a restricted range of elevations at which the guns can be loaded; the guns return to the loading elevation, are loaded, then return to the target elevation. The animation illustrates a turret where the rammer is fixed to the cradle that carries the guns, allowing loading to occur across a wider range of elevations.

Earlier turrets differed significantly in their operating principles. It was not until the last of the "rotating drum" designs described in the previous section were phased out that the "hooded barbette" arrangement above became the defining turret.