Vickers Mk IX 12" / 40 cal. Barbette
H.M.S. Formidable (1901)

Guns of MIKASA fire on the Russian Baltic fleet in a 1969 movie recreation
Vickers 12"/40 calibre turret fires on Russia's Baltic fleet in a 1969 movie recreation.

Profile section of one of the main 12" mountings and its ammunition handling machinery as installed on the the Formidable and the other London class battleships designed right at the turn of the century; first introduced in HMS Implacable of 1901. For an actual installation still in existence, see the dead similar turret from the Mikasa, commissioned in 1902. Note that this remains in essence a barbette mounting with a large armored gunhouse on top to protect the gun crew, rather than a true turret on the Coles model, in which the entire assembly rotates on a spindle.

Already in this section we can see the division of compartments which was to carry through the dreadnought era and WWII, with the magazines at the lowest level, handling ammunition and charges into the appropriate automated lifts; the working room directly below the gunhouse (turret), and the gun chamber itself. Around the edges and just below the working chamber were the great ring-and-pinion gears which turned the turret by hydraulic power and the compressed air cylinders used to spray down the guns' firing chambers after each round, to eliminate the possibility that a smoldering remnant of the last charge would blow the turret up when the powder for the next round was inserted (a very canny precaution when working around cordite and TNT).

The 12" guns used to arm the Royal Navy -- and about half the world's navies besides -- were manufactured by Vickers at its vast works at Barrow-on-Furness. Treatises have been written on the science of gun manufacture, and this is not the place to regurgitate them all. Suffice it to say the science of big gun manufacture, in terms of breech-loading rifles, came to maturity during the pre-Dreadnought era, at first in England and then rapidly in all the states jostling to rival England and each other. Just as gunnery technology reached a new stage of scientific and engineering excellence, engine and boiler technology, armor plate, and fire control accuracy entered a similar "golden age." In some cases the pre-WWI era was to mark the acme of the art, in others merely the prelude to a later platinum age which eclipsed even the most inspired mechanical inventions of our Edwardian forbears. Speaking of which, below is a cutaway diagram of the 12"/45 cal. Mark X turret as installed on HMS Dreadnought, commissioned in 1906. Featuring all-round loading and a few other extras, this marked the pinnacle of 12" gun development in Britain. Although a later 50-calibre version was installed on some battlecruisers, this was a problematic pattern subject to jams and barrel sag under prolonged use, conditions which did not hinder the prior model 45-calibre guns. With the Orion class dreadnoughts of 1909, the Royal Navy shifted to 13.5" guns, considered a leap forward at the time, although six years later eclipsed by the further jump to 15-in ordnance which remained in use through 1947.

The other principal system of barbette and gunhouse in the pre-dreadnought era was the Canet system used by the French Navy, and a few other navies who purchased ships from French yards. A particular client of the French shipyards was the Russian Navy (though in its wild buildup to the 1904 war with Japan, Russia bought in Germany, France, Italy, and the U.S.). The diagram below shows both the 6" secondary armament (left) and the 12" main guns (right) built under license in Russia for the Borodino class battleships (1904-5). As can be appreciated from the drawing, the Canet system relied on a relatively larger gunhouse, mounted on a much smaller armored tube protecting the ammunition train to the gunhouse. (Each of the Dreadnought's five 12" barbettes, above, was 27 feet across.) Rather than being overlapped by the lip of the wider barbette tube as in the British system, the Canet gunhouse overhung the top of the tube -- although much more so in the 6" and 9.4" versions than in mountings for the biggest guns, which required a much wider tube to accommodate the larger ammo train.

Diagram of Canet system turrets for Borodino Class battleships

In the Canet system, the machinery for rotating the turret was not so well protected; but the weight of the barbette armor was considerably reduced compared to the Vickers/Armstrong model. Both models worked admirably in practice. Most pre-1905 French battleships operated with single-gun main turrets only, the basis for the Canet system. This model worked better with its "native" single-gun model than when adapted to the twin-gun model used for the Tsesarevich and other Russian battleships built in Petersburg yards. Canet had more experience building twin 6" turrets, but in combat these proved far from immune to battle damage, being put out of action from Tsushima Kaikyo to Qingdao. To be fair, the ability of Japanese Elswick and Vickers turrets to survive even direct hits may owe more to the savoir-faire and élan of Japanese damage control engineers than to superiority of design, since a number of turrets from 8- to 12-in were temporarily disabled by Russian hits in the Russo-Japanese War.

Animated diagram of 15-in Battleship Turret, from Wikipedia

Animation of a British 15"/40 Armstrong twin turret operation, introduced 1915. Although considerably scaled up, this mounting operated almost identically to the later 12" mounts, Mks. X-XII of 1901 - 10.

Emphasis point For a diagram of one of USS Texas' 14" mountings (c. 1914) click here. For exclusive interior views of the Texas' No. 1 14" barbette and turret, click here.


View of metal lathes turning gun barrels in Coventry, UK, c. 1902

Gun barrels for the Royal Navy fill a machine shop in Coventry, circa 1902. Even before the advent of the dreadnoughts juiced up the pace of production, supplying the ordnance for the predreadnought navies was a major source of employment and profit for the huge armaments industries in participating countries. Then as now, armaments workers and owners exercised considerable political clout, not least in securing their jobs and profits. Concerns that arms spending could lead to a disastrous war were brushed off as the naïve prattlings of well-intentioned but ill-informed sissies.

12-in naval cannon in Vickers' gun foundry, c. 1901Here is one of the new 12"/40 cal Mk IX guns being assembled at Vickers' Gun Foundry, circa 1901. This all-steel weapon was state-of-the-art for the time, with a rifled barrel sleeve enclosed in a steel outer jacket and a steel firing chamber (the bulge at the breech end of the gun) reinforced by hoops of steel shrunk onto the outside of the gun as it cooled. The breech-lock mechanism was an improvement of the French half-turn safety model developed in the 1880s. It was not until the mid-Eighties that the Admiralty tilted to breech-loading weapons over muzzle loaders. The deciding moment was a turret accident aboard HMS Thunderer, in which a rifled muzzle-loading gun (RML) misfired in target practice and then was double-loaded, exploding catastrophically when the turret captain attempted to fire it again. Such an accident would have been patently impossible with a breech-loader, since the gun crew would have seen the unexploded charge on opening the breech to reload.

12-in naval cannon at Vickers' Eskmeals Proving Grounds, c. 1902Here, seen from the breech end, is one of the Formidable's four 12"/40 guns at the Eskmeals Proving Range. Guns were subjected to an exacting regimen of testing at Eskmeals before they were sent off to the dockyard for assembly into the vessel. With a muzzle vlocity of 2,567 ft/sec (782 m/sec), these 40-cal weapons could loft an 850-lb projectile close to 5 miles, or fire with devastating accuracy up to 3 miles. The gun barrels were 50 feet long and weighed 50.8 tons each. A new salvo could be loosed every 72 seconds. Formidable indeed!

12-in naval cannon loaded on special flatcar for rail delivery, c. 1902Elevated to an attention-grabbing angle for the camera, the 50-foot gun is seen loaded on a special railcar for delivery to Portsmouth DY (of course, the barrel will ride horizontal and well-lashed for the entire journey). Such railcars ran quite regularly to all British shipyards engaged in warship construction in the late Victorian era, but ever more frequently after the coming of the Dreadnought heated up the arms race between Britain and Germany. After all, after the Dreadnought any serious battleship mounted 10 or 12 high-profit, magnificently machined 12-inch guns instead of only four. But the numbers of ships only grew year by year.

The busy U.S. Naval Arsenal at D.C., 1904For the arms dealers, it must have seemed as though a never-ending golden age had dawned. The biggest bucks were pulled in at the top of the feeding chain, in the U.S., Britain and France. Italian and German arms deals were riddled with corruption and favoritism, despite high-flown rhetoric in their contracts. In times of flush spending, (so goes the theory) the prosperity trickles down to the less fortunate. So it was with the prolific free-lance arms dealers of the late 19th and early 20th century. Little more than racketeers, they often drove national policy in the small countries where they found their niche -- just as their big brothers at Vickers-Armstrong drove British policy and the house of Krupp drove it in Germany. Similar patterns were observed in Italy, Austria-Hungary, Spain, Greece, Russia and Turkey. Moneys that might have been better spent on education and infrastructure were instead lavished on warship construction and facilities, like more recent conditions in the sole remaining superpower -- first in armaments, dead last among industrial countries in child welfare and education, among other things.

Of course, the United States was no exception even a century ago in the age of the "Robber Barons" and the Progressives (strongly identified with imperialism under Theodore Roosevelt and Woodrow Wilson). Though a latecomer to the international naval arms race, America soon boasted very good technology and relatively high efficiency in turning out ships. Latin American republics favored U.S. contractors with a number of plum jobs, but Russia and Japan both bought selectively in the U.S. too. The scene at right shows the Washington, D.C. naval gun shop where much of the U.S. fleet's heavy artillery was produced. Date was 1904, at the height of the pre-dreadnought arms race.

A working foundry in France, late 19th cent.The gunnery situation in the early 1900s presented a case of technology's outrunning man's ability to use it to its fullest extent. The greatly improved range of the 12" gun (the standard calibre for fleet pre-dreadnought battleships) allowed engagement at far longer distances, while tactics still emphasized short-range battering followed by boarding, as in Nelson's day. But Admiral Togo conclusively demonstrated the advantage of accurate long-range gunfire, engaging the Russians at 2.27-mile range at the Battle of Tsushima in 1905 and sinking most of their fleet with long-range gunfire (supplemented by torpedoes despatching already-battered ships). Targeting accuracy at that range, however, was sadly lacking as the naval powers roared into the Dreadnought era only a few years later. The waste of ammunition in actions such as Santiago and Tsushima was phenomenal -- on the order of 100:1 shots per hit -- even by the winning sides. With the advent of the dreadnought battleship, as many as 3 times the number of guns were deployed per ship as in the pre-dreadnought battleships, compounding the problem. But help was on its way as the ingenious engineers and mathematicians of Britain and other countries devised complex analog computers to determine range and deflection along with variables such as ships' speeds and courses, wind strength and direction, and convert them to firing solutions couched in training coordinates, elevation, and charge specifications. The premier instrument they devised was known as the Dreyer Fire Control Table. Further advances were made with the development of the Vickers Director Firing System, invented by retired Adm. Sir Percy Scott. This device meshed all main guns on a battleship into coordinated salvo firing. Old-time navy gunners held out against the adoption of the new technology, but First Lord of the Admiralty Winston Churchill insisted on competitive trials. The improvement in accuracy with the introduction of these devices was dramatic, indisputable. These technical aids were in use on most British fleet units by the beginning of WWI -- on all but 2 dreadnoughts by 1916 --, and continued in improved form through WWII, though modified by the advent of radar and spotting aircraft for even more accurate battleship bombardment. The analog targeting computers manufactured for the U.S. Iowa class in 1942 were still in use in Operation Desert Storm, 1991: more durable than their electronic descendants, and equally accurate for the purpose of landing a 1500-lb projectile on a given spot up to 20 miles away.

Forward 12-in turret of IJN MIKASA
Vickers 12"/40 Mk IX forward turret of the Imperial Japanese flagship Mikasa, commissioned 1902.