The Canon de 138 mm Modèle 1893 was a medium-calibre

naval gun Naval artillery is artillery mounted on a warship, originally used only for naval warfare and then subsequently used for naval gunfire support, shore bombardment and anti-aircraft roles. The term generally refers to tube-launched projectile-firi ...

of the

French Navy The French Navy (french: Marine nationale, lit=National Navy), informally , is the maritime arm of the French Armed Forces and one of the five military service branches of France. It is among the largest and most powerful naval forces in t ...

used during

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

and

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

. It was carried by a number of ships built during the 1890s including the

pre-dreadnought battleship Pre-dreadnought battleships were sea-going battleships built between the mid- to late- 1880s and 1905, before the launch of in 1906. The pre-dreadnought ships replaced the ironclad battleships of the 1870s and 1880s. Built from steel, prote ...

s. Guns from scrapped warships were later mounted on auxiliary ships during the 1930s.Campbell, p. 300

Design

The 45-

calibre In guns, particularly firearms, caliber (or calibre; sometimes abbreviated as "cal") is the specified nominal internal diameter of the gun barrel bore – regardless of how or where the bore is measured and whether the finished bore match ...

''Mle 1893'' was the culmination of a family of guns first produced in 1884. The design progressed from the 30-caliber Mle 1884 and Mle 1891 guns, to the 44-caliber Mle 1888 and Mle 1891 guns and lastly the 45-caliber Mle 1887, Mle 1891 and Mle 1893 guns. The 44-caliber and 45-caliber guns had nearly identical ballistic performance and used the same ammunition. The Mle 1893 used the typical built-up construction of its time. It had a screw breech and used separate-loading ammunition. In the battleships it was installed in armored casemates, using central pivot mounts, but no details are available.

Railway artillery

A number of mle 1884 guns were modified to become railway artillery under the designation ''Canon de 140 sur affut-truc mle 1884'' during 1914. The conversion entailed mounting the gun carriage on a simple flatbed rail wagon built from steel I beams and timbers with five

variable gauge A variable gauge system allows railway vehicles in a train to travel across a break of gauge between two railway networks with different track gauges. For through operation, a train must be equipped with special bogies holding variable gauge whe ...

axles that allowed the guns to transition from

standard gauge A standard-gauge railway is a railway with a track gauge of . The standard gauge is also called Stephenson gauge (after George Stephenson), International gauge, UIC gauge, uniform gauge, normal gauge and European gauge in Europe, and SGR in Ea ...

to narrow gauge allowing the guns to be brought closer to the front.
The recoil system for the mle 1884 consisted of a U shaped gun cradle which held the

trunnion A trunnion (from Old French "''trognon''", trunk) is a cylindrical protrusion used as a mounting or pivoting point. First associated with cannons, they are an important military development. Alternatively, a trunnion is a shaft that positions a ...

ed barrel and a slightly inclined firing platform with a hydro-gravity recoil system. When the gun fired the hydraulic buffers slowed the recoil of the cradle which slid up a set of inclined rails on the firing platform and then returned the gun to battery by the combined action of the buffers and gravity. Elevation was largely the same but there was no traverse so in order to aim the gun had to be drawn across a section of curved track or placed on a turntable. In order to anchor the gun, there was an attachment at the front of the carriage for a tie bar which attached to an

earth anchor An earth anchor is a device designed to support structures, most commonly used in Geotechnical engineering, geotechnical and construction applications. Also known as a ground anchor, percussion driven earth anchor or mechanical anchor, it may be ...

and there was an ammunition hoist at the rear of the carriage. There were also four wooden beams with one between each axle which were lowered lay across the tracks by screw jacks to take weight off of the axles.

Ammunition

The propellant charge for the ''Mle 1893'' was contained in a cartridge case.

Notes

References

* * {{DEFAULTSORT:Canon de 138 mm Modele 1893 naval gun Naval guns of France 138 mm artillery