Barbette

Cross-section of a 19th-century fortification; a gun at position "C" would be firing from a barbette position

The use of barbette mountings originated in ground fortifications. The term originally referred to a raised platform on a rampart for one or more guns, enabling them to be fired over a parapet.[2] This gave rise to the phrase en barbette, which referred to a gun placed to fire over a parapet, rather than through an embrasure, an opening in a fortification wall. While an en barbette emplacement offered wider arcs of fire, it also exposed the gun's crew to greater danger from hostile fire.[3] In addition, since the barbette position would be higher than a casemate position—that is, a gun firing through an embrasure—it would generally have a greater field of fire. The American military theorist Dennis Hart Mahan suggested that light guns, particularly howitzers, were best suited for barbette emplacements since they could fire explosive shells and could be easily withdrawn when they came under enemy fire.[4] Fortifications in the 19th century typically employed both casemate and barbette emplacements. For example, the Russian Fort Constantine outside Sevastopol was equipped with 43 heavy guns in its seaward side during the Crimean War in the mid-1850s; of these, 27 were barbette mounted, with the rest in casemates.[5]

A modified version of the barbette type was the disappearing gun, which placed a heavy gun on a carriage that retracted behind a parapet for reloading; this better protected the crew, and made the gun harder to target, since it was only visible while it was firing.[6] The type was usually used for coastal defence guns. As naval gun turrets improved to allow greater elevation and range, many disappearing guns, most of which were limited in elevation, were seen as obsolescent; with aircraft becoming prominent in the First World War, they were largely seen as obsolete. However, they remained in use through the early Second World War, at least by the United States, due to limited funding for replacement weapons between the wars.[7][8]

Later heavy coastal guns were often protected in hybrid installations, in wide casemates with cantilevered overhead cover partially covering a barbette or gunhouse mount.[9]

Illustration of several armored ships from the 1880s, showing the degree of experimentation with armament arrangements

Following the introduction of ironclad warships in the early 1860s, naval designers grappled with the problem of mounting heavy guns in the most efficient way possible. The first generation of ironclads employed the same broadside arrangement as the old ship of the line, but it was not particularly effective for ahead or stern fire. This was particularly important to designers, since the tactic of ramming was revived following its successful employment at the decisive Austrian victory at the Battle of Lissa in 1866. Ramming required a ship to steam directly at its opponent, which greatly increased the importance of end-on fire. Designers such as Cowper Phipps Coles and John Ericsson designed the first gun turrets in the 1860s, which gave the guns a wide field of fire. These turrets were exceedingly heavy, which required them to be placed low in the ship to reduce top-weight—and produced a dangerous tendency to capsize in heavy seas, amply demonstrated by the loss of HMS Captain and Coles himself with the ship in a gale in 1870.[10][11][12]

In the 1870s, designers began to experiment with an en barbette type of mounting. The barbette was a fixed armoured enclosure protecting the gun. The barbette could take the form of a circular or elongated ring of armour around the rotating gun mount over which the guns (possibly fitted with a gun shield) fired. The barbette system reduced weight considerably, since the machinery for the rotating gun mount, along with the mount itself, was much lighter than that required for the gun house of a turret.[13] The savings in weight could then be passed on to increase armour protection for the hull, improve coal storage capacity, or to install larger, more powerful engines.[14] In addition, because barbettes were lighter, they could be placed higher in the ship without jeopardizing stability, which improved their ability to be worked in heavy seas that would have otherwise rendered turrets unusable. This also permitted a higher freeboard, which also improved seakeeping.[15]

Ironclads equipped with barbettes were referred to as "barbette ships" much like their contemporaries, turret ships and central battery ships, which mounted their heavy guns in turrets or in a central armored battery.[16] Many navies experimented with all three types in the 1870s and 1880s, including the British Admiral-class battleships,[17] the French Marceau-class ironclads,[18] the Italian Italia-class battleships,[19] and the German Sachsen-class ironclads, all of which employed barbettes to mount their heavy guns.[20] All of these navies also built turret and or central battery ships during the same period, though none had a decisive advantage over the other.[21] The British and the Russian navies experimented with using disappearing guns afloat, including on the British HMS Temeraire, the Russian monitor Vitse-admiral Popov, and some of the Ekaterina II-class battleships. They were not deemed particularly successful and were not repeated.[6]

USS Maryland under construction in 1917, showing the forward two barbettes without the gun turrets installed

In the late 1880s, the debate between barbette or turret mounts was finally settled. The Royal Sovereign class, mounted their guns in barbettes, but the follow-on design, the Majestic class, adopted a new mounting that combined the benefits of both kinds of mounts. A heavily armoured, rotating gun house was added to the revolving platform, which kept the guns and their crews protected. The gun house was smaller and lighter than the old-style turrets, which still permitted placement higher in the ship and the corresponding benefits to stability and seakeeping. This innovation gradually became known simply as a turret, though the armored tube that held the turret substructure, which included the shell and propellant handling rooms and the ammunition hoists, was still referred to as a barbette. These ships were the prototype of the so-called pre-dreadnought battleships, which proved to be broadly influential in all major navies over the next fifteen years.[22][23]

Ships equipped with barbette mountings did not see a great deal of combat, owing to the long period of relative peace between their appearance in the 1870s and their obsolescence in the 1890s. Some barbette ships saw action during the British Bombardment of Alexandria in 1882,[24] and the French ironclad Triomphante participated in the Battle of Fuzhou during the Sino-French War in 1884.[25] The two Chinese ironclads, Dingyuan and Zhenyuan, that took part in the Battle of the Yalu River during the First Sino-Japanese War in 1894, carried their main battery in barbettes, though they were equipped with extensive gun shields that resembled turrets. The shields were nevertheless only proof against small-arms fire.[26] Three of their opponents at the Yalu River, the Japanese Matsushima-class cruisers, also mounted their guns in open barbettes.[27] Those barbette ships that survived into World War I were typically used only for secondary purposes. For example, the French Marceau was used as a repair ship for submarines and torpedo boats,[28] while the German Württemberg was employed as a torpedo training ship.[20] A handful of barbette ships did see action during the war, including HMS Revenge, which bombarded German positions in Flanders in 1914 and 1915.[29]

Rear "Cheyenne"-pattern gun position on a B-17G Flying Fortress

When applied to military aircraft, largely in aviation history books written by British historians, a barbette is a position on an aircraft where a gun is in a mounting which has a restricted arc of fire when compared to a turret, or which is remotely mounted away from the gunner. As such it is frequently used to describe the tail gunner position on bombers such as the Boeing B-17 Flying Fortress,[30] with American aviation books frequently describing the position as a tail gun turret,[31] or simply as a tail gun.[32]

The term "barbette" is also used by some, again primarily British historians, to describe a remotely aimed and operated gun turret emplacement[33] on almost any non-American military aircraft of World War II, but it is not usable in a direct translation for the varying German language terms used on Luftwaffe aircraft of that era for such emplacements. As just one example, the German Heinkel He 177A heavy bomber had such a remotely operated twin-MG 131 machine gun Fernbedienbare Drehlafette FDL 131Z (Z - "zwilling"/twin) powered forward dorsal gun turret, with the full translation of the German term comprising the prefix as "Remotely controlled rotating gun mount".[34] The term "lafette" in German actually refers to a gun carriage of nearly any type, with its original use as being for the mounting design for bombard-style siege guns of the Middle Ages.

• "B-29s Over Britain". Flight: 572–574. 19 June 1947. Retrieved 25 March 2014.
• Beeler, John (2001). Birth of the Battleship: British Capital Ship Design, 1870–1881. London: Chatham. ISBN 1-86176-167-8.
• Beeler, John (1997). British Naval Policy in the Gladstone-Disraeli Era, 1866–1880. Stanford University Press. ISBN 0-8047-2981-6.
• Berhow, Mark A., ed. (2015). American Seacoast Defenses, A Reference Guide, Third Edition. McLean: CDSG Press. ISBN 978-0-9748167-3-9.
• "Bristol Armament Development". Flight: 232. 16 February 1950. Retrieved 25 March 2014.
• Brown, D. K. (1979). Roberts, John (ed.). "Shells at Sevastopol". Warship. London: Conway Maritime Press. III: 74–79.
• Burt, R.A. (1988). British Battleships 1889–1904. Annapolis, Maryland: Naval Institute Press. ISBN 0-87021-061-0.
• Feron, Luc (1985). "French Battleship Marceau". Warship International. Toledo: International Naval Research Organization. XXII (1): 68–78. ISSN 0043-0374.
• Forsyth, Robert (2009). Fw 190 Sturmböcke Vs B-17 Flying Fortress: Europe 1944–45. Oxford: Osprey Publishing. ISBN 9781846039416.
• Gardiner, Robert, ed. (1979). Conway's All the World's Fighting Ships 1860–1905. Greenwich: Conway Maritime Press. ISBN 0-8317-0302-4.
• Griehl, Manfred; Dressel, Joachim (1998). Heinkel He 177 - 277 - 274. Shrewsbury: Airlife Publishing. ISBN 1-85310-364-0.
• Gröner, Erich (1990). German Warships 1815–1945. Annapolis: Naval Institute Press. ISBN 0-87021-790-9.
• Hodges, Peter (1981). The Big Gun: Battleship Main Armament, 1860–1945. Annapolis: Naval Institute Press. ISBN 0870219170.
• Mahan, Dennis Hart (1867). An Elementary Course on Military Engineering [covering] Field Fortifications, Military Mining, and Siege Operations. New York: J. Wiley. OCLC 3157043.
• Reuter, Claus (1999). Development of Aircraft Turrets in the AAF, 1917–1944. German-Canadian Museum of Applied History. OCLC 499763163.
• Robertson, John (1754). The Elements Of Navigation; Containing The Theory and Practice: With All the Necessary Tables : To which is Added, A Treatise of Marine Fortification ; For the Use of the Royal Mathematical School at Christ's Hospital, and the Gentlemen of the Navy ; In Two Volumes. Nourse. pp. 619–640.
• Sondhaus, Lawrence (2001). Naval Warfare, 1815–1914. London: Routledge. ISBN 9780415214780.
• "The Moncrieff System of Disappearing Gun Carriages". The Illustrated Naval and Military Magazine. London: W. H. Allen & Co. III: 120–124. 1886. OCLC 220760873.
• Wilson, Herbert Wrigley (1896). Ironclads in Action: A Sketch of Naval Warfare from 1855 to 1895, Volume 1. London: S. Low, Marston and Co. OCLC 1111061.

Wikimedia Commons has media related to Gun barbettes.

• "Barbette" . Encyclopædia Britannica. Vol. 3 (11th ed.). 1911.