Turret

In architecture, a turret (from Italian: torretta, little tower; Latin: turris, tower) is a small tower that projects vertically from the wall of a building such as a medieval castle. Turrets were used to provide a projecting defensive position allowing covering fire to the adjacent wall in the days of military fortification. As their military use faded, turrets were used for decorative purposes, as in the Scottish baronial style.

A turret can have a circular top with crenellations as seen in the picture at right, a pointed roof, or other kind of apex. It might contain a staircase if it projects higher than the building; however, a turret is not necessarily higher than the rest of the building; in this case, it is typically part of a room, that can be simply walked into – see the turret of Chateau de Chaumont on the collection of turrets, which also illustrates a turret on a modern skyscraper.

A building may have both towers and turrets; turrets might be smaller or higher but the difference is generally considered to be that a turret projects from the edge of the building, rather than continuing to the ground. The size of a turret is therefore limited by technology, since it puts additional stresses on the structure of the building. It would traditionally be supported by a corbel.

Turret (Hadrian's Wall)

A turret was a small watch tower, incorporated into the curtain wall of Hadrian's Wall. The turrets were normally spaced at intervals of one third of a Roman mile (equivalent to 495 metres (541 yd)) between Milecastles, giving two Turrets between each Milecastle.

Numbering system and naming

Many turrets also have a name, which is often shown in brackets following the number. For example, Brunton Turret is often referred to as 'Turret 26B (Brunton)'.

Turf Wall

Where the Turf Wall and Stone Walls diverge from one another (just to the east of Birdoswald), Milecastles and Turrets unique to the Turf Wall are given a 'TW' suffix, for example 'T50bTW'. A suffix of 'SW' may also be used to uniquely identify a turret as belonging to the 'Stone Wall'.

Cumbrian Coast

Although Hadrian's Wall itself ended (at its western terminus) just beyond the fort of Maia at the modern village of Bowness-on-Solway on the Cumbrian coast, the system of milecastles and turrets continued beyond this point, as far as Flimby, with comparable spacing. However, the nomenclature adopted for the Milecastle equivalent is 'Milefortlet', and the equivalent of the turret is a Tower. The numbering system adopted for the towers along the Cumbrian Coast is (for example) 'T21a CC' (the 'CC' suffix meaning 'Cumbrian Coast'), though the CC suffix is often not used if the reference is clear from the context, so care must be taken not to confuse (for example) 'T21a' meaning 'Turret 21a', and 'T21a' meaning 'Tower 21a'.

Turret deck ship

A turret deck ship is a type of merchant ship with an unusual hull, designed and built in the late 19th and early 20th centuries. The hulls of turret deck vessels were rounded and stepped inward above their waterlines. This gave some advantages in strength and allowed them to pay lower canal tolls under tonnage measurement rules then in effect. The type ceased to be built after those rules changed.

Development

Turret deck ships were inspired by the visit of the US whaleback vessel Charles W. Wetmore to Liverpool in 1891. Like others of the type, Wetmore had a hull in the form of a flattened cigar, with a continuous curve above the waterline to where the sides met amidships. The superstructure atop the hull was in round or oval "turrets", so named because of their resemblance to gunhouses on contemporary warships.

In 1893 William Doxford and Sons Ltd. ("Doxford") of Sunderland, England built one whaleback under license from the type's designer, but had already built its first turret deck ship to a design by Arthur Havers, the concern's chief draughtsman. Havers toned down the more radical features of the whaleback. His design retained conventional bows and sterns instead of the upswept conoid "snout" of the whaleback. Instead of a rounded hull, the hull of a turret vessel was stepped inward above the waterline, but the horizontal and vertical surfaces of the hull met in curves rather than by right angles as in conventional ships. Finally, the design joined the rounded turrets of whalebacks into one long and narrow rectangular structure (also called a "turret") of about half the beam, and used that space as part of the hold.