Superfiring armament is a naval design technique in which two or more turrets are located one behind the other, with the rear turret located above ("super") the one in front so that it can fire over the first. This configuration meant that both forward and aft turrets could fire at any target within their sector, even when the target was directly ahead of the turrets.

History

Historically, large surface warships were known by the generic label of

battleship A battleship is a large, heavily naval armour, armored warship with a main battery consisting of large naval gun, guns, designed to serve as a capital ship. From their advent in the late 1880s, battleships were among the largest and most form ...

s, with a further distinction between

pre-dreadnought Pre-dreadnought battleships were sea-going battleships built from the mid- to late- 1880s to the early 1900s. Their designs were conceived before the appearance of in 1906 and their classification as "pre-dreadnought" is retrospectively appl ...

s and

dreadnought The dreadnought was the predominant type of battleship in the early 20th century. The first of the kind, the Royal Navy's , had such an effect when launched in 1906 that similar battleships built after her were referred to as "dreadnoughts", ...

s. The era of technical evolution occurred roughly from 1900 to 1945. Part of the technical evolution was driven by the need to compress as much large-gun firepower into the smallest space possible. In early designs, the large-caliber turrets were all located on the same plane firing to one side or the other. In firing ahead or to the rear, usually only the forward-most or rearmost turret could fire, especially at low angles. An early concern was that the pressure and shock from the higher turret would damage the lower one when firing over the top. In 1908,

United States Navy The United States Navy (USN) is the naval warfare, maritime military branch, service branch of the United States Department of Defense. It is the world's most powerful navy with the largest Displacement (ship), displacement, at 4.5 millio ...

tests using the

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as the testbed proved that superfiring was safe. The result was the design for the first (commissioned in 1910). The first ship with superfiring artillery (though not of the same caliber), was the French battleship ''Henri IV'', launched in 1899.Roger Chesneau, Eugène Kolesnik (ed.): ''Conway's All the World's Fighting Ships 1860-1905'', Conway Maritime Press, London, 1979, , p.295 Superfiring was not limited to two turrets. For example, the ''Atlanta''-class of

light cruiser A light cruiser is a type of small or medium-sized warship. The term is a shortening of the phrase "light armored cruiser", describing a small ship that carried armor in the same way as an armored cruiser: a protective belt and deck. Prior to thi ...

, which were developed and built for service in

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

, utilized a triple-overlap system both forward and astern, their armament of dual-mount 5"/38 caliber dual-purpose main armament having a nearly unobstructed

arc of fire The field of fire or zone of fire (ZF) of a weapon, or group of weapons, is the area around it that can easily and effectively be reached by projectiles from a given position. Field of fire The term originally came from the ''field of fire'' in f ...

. The British ''Dido''-class, which were also light cruisers armed entirely with dual-purpose guns (the 5.25" Mk 1), also had three turrets forward, with two aft.

Advantages and disadvantages

Advantages of superfiring turrets over non-superfiring arrangements include improved firing arcs for all except the foremost and rearmost turrets, as well as an increase of useful deck space on which to build the ship's superstructure due to the concentration of the main batteries towards the ends of the ship. Depending on the design of the ship and its weapons, it may also help to avoid issues with the ship's propulsion. Fuso1944

The disadvantage of this arrangement is a higher center of mass as a result of the higher placement of turrets, thus decreasing the

metacentric height The metacentric height (GM) is a measurement of the initial static stability of a floating body. It is calculated as the distance between the centre of gravity of a ship and its '' metacentre''. A larger metacentric height implies greater initial ...

. The resulting decrease in stability may need to be corrected by compromises elsewhere to keep the center of mass low. Because of this, superfiring arrangements, while common, are not used exclusively. Examples of non-superfiring designs include but are not limited to the '' Gangut'', '' Imperatritsa Mariya'', and '' Imperator Nikolai'' classes of battleships built for the Imperial Russian navy, as well as modern ships such as the ''Zumwalt''-class destroyers. In addition, many ships, such as the ''New York''-class battleships, used combinations of superfiring and non-superfiring arrangements. Exclusively non-superfiring arrangements also remained common on destroyers.

Notes

References

{{reflist Battleships