The Barbette: A Lightweight Gun Mounting (1870s - 1890s)
Above, a Royal Navy twin barbette mount on HMS Royal Sovereign, commissioned 1892. Before the advent of the turret, warships carried their artillery ranged along the sides in a broadside. While the gun carriages allowed limited movement for aiming, it was up to the captain to maneuver his ship so the gunners could hit the target within these limitations. With the coming of the turret, the unit's training gear could point the guns toward any point not masked by elements of its own ship, regardless of how the ship was situated. But the turret had drawbacks too, mainly the great weight of the armor and the mechanism for turning the gunhouse. In the 1860s, the barbette was invented as a lighter-weight alternate mounting. The gun or guns rotated on a turntable surrounded by an armored parapet, while the ammunition lifts were protected by an armored tube beneath the gun position. With less weight concentrated in the mount, it became possible to station the guns higher in the ship without upsetting the delicate stability of the vessel. But in the original barbette style, there was no overhead protection provided for the gun crews: this was the trade-off for the greatly reduced topweight.
At left, a plan for an early barbette on the ironclad wooden barbette ship l'Ocean, drawn by France's premier naval architect, Dupuy deLôme, circa 1868. Four 9.4" barbettes rose from the corners of an armored central battery, containing four 10.8" guns disposed in conventional carriages on the main deck. The French were the first to perfect the interrupted screw breech block mechanism, making the breech-loading gun viable. Britain, spooked by a gory breech failure, stuck with muzzle-loading guns through the mid-1880s. At that time, an even more horrific mishap -- the accidental double-loading of a gun on board HMS Thunderer on top of a misfired charge, leading to a deadly turret explosion -- brought about a change in policy. The mishap manifestly would have been impossible with breech-loading guns, since the crew would have seen the debris inside the gun when they opened the breech to reload. This influenced the decision to switch.
Laid down in 1877 and commissioned in 1883, at the peak of the barbette movement, the French battleship Amiral Duperré mounted four 13.4" guns in barbettes. The following class, the 3 Amiral Baudins, progressed to a more logical layout with three 14.6" barbettes, all on the centerline. The shielding for the gun crews changed from open at the front/closed at the rear to closed at the front/open at the rear, affording better protection from incoming shellfire.
An early barbette mounting in the Royal Navy: an 11" muzzle-loader aboard HMS Téméraire (1877). This photo shows the low parapet shielding the gunners. Replacing the unprotected pivot guns of the Civil War era, barbette guns sat on stationary carriages that rotated on a mechanized turntable. This enabled the use of far heavier guns. In the great Victorian inventions department, the design of Témeraire's barbettes was itself unique. On firing, the recoil of the gun caused it to both drop and rotate through 180 degrees; this allowed re-loading without the exposure of the gun crew to aimed enemy fire. After loading, the gun was rotated by a hydraulic system back into the firing position. While this system worked fine, it was slow-loading. Moreover, it was extremely heavy, adding excessive topweight to the ship: exactly what a barbette was meant to circumvent. Use of the disappearing guns was never repeated in the Royal Navy. The Russian Navy produced one battleship for Black Sea service -- the Catherine the Great -- with three pairs of disappearing guns, but three follow-on sister ships were completed with conventional barbettes with armored gunhouses.
The Marceau was the last French barbette battleship, laid down in 1881 and commissioned ten years later in 1891, name ship of a class of four. Note the enclosed gunhouse protecting each big gun: such protection became de rigueur with the advent of dampened-recoil, quick-firing medium-calibre guns in the 1880s. Marceau carried four 13.4" guns in the "diamond pattern" favored by France -- one each at bow and stern, and one on each beam. After 1892, French battleships would be built in this configuration, but using turret mounts rather than barbettes. Meantime, barbette mountings had become all the rage internationally, copied in the Italian, Russian, and British navies.
12" aft barbette mounting on the Austro-Hungarian battleship Kronprinz Rudolf, showing the interior of the gunhouse formed by the shielding around the top and back.
A 13.5" gun being lowered into the forward barbette of HMS Camperdown at the Royal Dockyard, Malta.
In the 1870s and 1880s, Italy, Britain, and France mounted a "Monster Gun Competition." The Italians had the largest afloat, 17.7" Armstrong rifles fabricated in Britain for the battleships Italia and Lepanto; Britain also came up with an impressive but rather impractical 16.25" model. These immense guns were extremely heavy; their practicality was only made possible by the light weight of the barbette mounting. Of these ships, only the Inflexible -- and later the Victoria -- mounted their giant guns in turrets. The Admiral-class battleship HMS Benbow mounted two 16.25" guns in single barbettes, of which a plan is above. The top of the ammo lift is visible directly behind the gun's breech, rising through its armored tube: ancestor to the 33-foot-wide barbette tubes on the giant battleships of World War II. Note that the Benbow's is not a round mounting, but a parapet rounded on one side and rougly triangular on the inboard end. British battleships of the time lay low to the waves; tall barbettes kept the mounts dry and gave gunners the necessary elevation to aim accurately.
The Italian barbette ship Re di Sicilia viewed on her trials. Once again, a low-freeboard hull was compensated for by high-sided barbettes -- these holding two 13.5" guns in each. The Sicilia and her two sisters were the fastest battleships afloat when launched. Their design reflected concern for protection against enemy QF shellfire with additional armor worked into their sides while under construction (further reducing the ships' designed freeboard) and armored shields erected over the gun crews. Even with this additional protection, the mounts were still lighter than conventional Coles turrets.
This was a step in the direction of the all-around armored gunhouse at the top of a barbette tube, revolving with the guns. By 1895-1900, these gunhouses were being loosely called turrets, although their structure was quite different from the original Coles and Ericsson turrets of the 1860s. By the turn of the century, these new "turrets" married to a stationary barbette tube, were universally adopted for large capital ships. Mounts often housed single or twin guns; by 1912 triple 12" mounts were being produced. Quadruple mounts enjoyed a brief vogue in the years leading up to World War II, chiefly in the French and British fleets.
