The Mortier de 270 mm modèle 1885 was a French

heavy mortar A mortar is usually a simple, lightweight, man-portable, muzzle-loaded weapon, consisting of a smooth-bore (although some models use a rifled barrel) metal tube fixed to a base plate (to spread out the recoil) with a lightweight bipod mount and a ...

employed as

siege artillery Siege artillery (also siege guns or siege cannons) are heavy guns designed to bombard fortifications, cities, and other fixed targets. They are distinct from field artillery and are a class of siege weapon capable of firing heavy cannonballs or ...

during the

First World War 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 ...

History

The Mortier de 270 mm G mle 1885 was one of a series of heavy artillery pieces designed by Colonel Charles Ragon de Bange. On 11 May 1874 three de Bange heavy cannons ( 120 mm,

155 mm 155 mm (6.1 in) is a common, NATO-standard, artillery caliber. It is defined in AOP-29 part 1 with reference to STANAG 4425. It is commonly used in field guns, howitzers, and gun-howitzers. Land warfare The caliber originated in France after ...

, 240 mm) and two mortars ( 220 mm, 270 mm) were ordered by the

French Army The French Army, officially known as the Land Army (french: Armée de Terre, ), is the land-based and largest component of the French Armed Forces. It is responsible to the Government of France, along with the other components of the Armed For ...

. The mle 1885 was advanced for its time due to being built completely of steel instead of a steel liner and

cast iron Cast iron is a class of iron–carbon alloys with a carbon content more than 2%. Its usefulness derives from its relatively low melting temperature. The alloy constituents affect its color when fractured: white cast iron has carbide impuriti ...

reinforcing

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of the previous ''Canon de 240 mm C mle 1870''-87. The later Mortier de 270 mm modèle 1889 was based on the mle 1885 and adapted to the

coastal artillery Coastal artillery is the branch of the armed forces concerned with operating anti-ship artillery or fixed gun batteries in coastal fortifications. From the Middle Ages until World War II, coastal artillery and naval artillery in the form of c ...

role by fitting the same barrel to a different carriage. Although the majority of combatants had heavy field artillery prior to the outbreak of the First World War, none had adequate numbers of heavy guns in service, nor had they foreseen the growing importance of heavy artillery once the

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stagnated and

trench warfare Trench warfare is a type of land warfare using occupied lines largely comprising military trenches, in which troops are well-protected from the enemy's small arms fire and are substantially sheltered from artillery. Trench warfare became a ...

set in. Fortresses, armories, coastal fortification and museums were scoured for heavy artillery and sent to the front. Suitable field and rail carriages were built for these guns in an effort to give their forces the heavy field artillery needed to overcome trenches and hardened concrete fortifications.

Design

The mle 1885 was

breech loaded A breechloader is a firearm in which the user loads the ammunition (cartridge or shell) via the rear (breech) end of its barrel, as opposed to a muzzleloader, which loads ammunition via the front ( muzzle). Modern firearms are generally breech ...

with a de Bange obturator, and used separate loading bagged charges and projectiles. The recoil system for the mle 1885 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 hydraulic buffers. When the gun fired the hydraulic buffer slowed the recoil of the cradle which slid up a set of inclined rails on the firing platform and then returned to position by the combined action of the buffers and gravity. The carriage allowed for high angles of elevation and pivoted at the front for 30° of traverse. At the outbreak of the First World War, it is estimated there 32 mle 1885's available. For transport the mle 1885 could be broken down into four wagon loads for horse or motor traction. The mortars could also be transferred to narrow gauge rail wagons for the final leg to their firing positions. These narrow gauge tracks were also used to re-position the mortars and bring up their ammunition and supplies. Site preparation needed up to 15 men directed by 2 officers and took 7-8 hours. Site preparation included creating a base of wooden beams then assembling the mortar with cranes and block & tackle.

Weapons of comparable performance and era

* 28 cm howitzer L/10 - A similar Japanese howitzer * 28 cm Haubitze L/12 - A similar German howitzer * 24 cm Mörser M 98 - A similar Austro-Hungarian mortar

References

{{DEFAULTSORT:Mortier de 270 mm modèle 1885 Artillery of France World War I artillery of France World War I guns Siege artillery