9.45 inch Heavy Mortar
Encyclopedia
The ML 9.45 inch Heavy Trench Mortar, nicknamed the Flying Pig, was a large calibre mortar
of World War I
and the standard British heavy mortar from Autumn 1916 onwards. It was a modification of an original French design, the Mortier de 240 mm developed by Batignolles Company of Paris and introduced in 1915. Britain manufactured the modified version under license.
In June 1916, following unsatisfactory trials with the French model, Britain replaced them with 30 of its own model, firing a 150 pound bomb, followed by 200 more in December 1916.
The Mark I with 51 inches (1,295.4 mm) barrel was introduced from June 1916. In 1917, the Mark II and Mark III followed with 69 inches (1,752.6 mm) barrel, and small numbers of Mark IV.
It was operated by crews of the Royal Garrison Artillery
which was the part of the British Army
that operated the heaviest artillery weapons, formed into batteries of 4 mortars attached to each division
, designated "V/nn" where nn = division number. From February 1918 they were reorganised and moved from divisional to corps
control.
The weapon was dismantled for transport, requiring 4 carts for the barrel, base, carriage and ammunition.
In action, a heavy timber platform was constructed embedded in the ground, on which the mortar base was immovably secured. The mortar carriage sat on the base and could traverse. The mortar barrel and breech were mounted on the carriage which provided elevation
.
They were used in the "siege warfare" on the Western Front
to destroy enemy strongpoints, bunkers and similar "hard" targets which were invulnerable to lighter mortars and field guns. The US Army handbook described it : "... the use for which it is primarily adapted is in the bombardment of strongly protected targets - dwellings, covered shelters, command posts, entrances to galleries, etc - or in the destruction of sectors of trenches, salients and the like.". Their effectiveness decreased late in the war as German policy changed to a lightly held frontline, hence decreasing available targets, and they became redundant when the war of movement resumed late in 1918.
Both the propellant charge appropriate for the required range and the bomb were loaded via the muzzle. Usually a Lee-Enfield rifle's bolt action mechanism was screwed into the breech. A special blank rifle cartridge was loaded and was triggered by pulling a lanyard
, and fired into an igniter at the base of the mortar chamber, igniting the propellant charge and launching the bomb.
Mortar (weapon)
A mortar is an indirect fire weapon that fires explosive projectiles known as bombs at low velocities, short ranges, and high-arcing ballistic trajectories. It is typically muzzle-loading and has a barrel length less than 15 times its caliber....
of World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
and the standard British heavy mortar from Autumn 1916 onwards. It was a modification of an original French design, the Mortier de 240 mm developed by Batignolles Company of Paris and introduced in 1915. Britain manufactured the modified version under license.
History
The British ML 9.45 inches (240 mm) mortar was a design based on the French 240 mm mortar in 1915 and introduced in 1916. The British version differed from the French LT weapon in that the propellant charge was loaded through the muzzle whereas the French 240 mm had the charge loaded through the breech in a brass cartridge case.In June 1916, following unsatisfactory trials with the French model, Britain replaced them with 30 of its own model, firing a 150 pound bomb, followed by 200 more in December 1916.
The Mark I with 51 inches (1,295.4 mm) barrel was introduced from June 1916. In 1917, the Mark II and Mark III followed with 69 inches (1,752.6 mm) barrel, and small numbers of Mark IV.
Combat use
Royal Garrison Artillery
The Royal Garrison Artillery was an arm of the Royal Artillery that was originally tasked with manning the guns of the British Empire's forts and fortresses, including coastal artillery batteries, the heavy gun batteries attached to each infantry division, and the guns of the siege...
which was the part of the British Army
British Army
The British Army is the land warfare branch of Her Majesty's Armed Forces in the United Kingdom. It came into being with the unification of the Kingdom of England and Scotland into the Kingdom of Great Britain in 1707. The new British Army incorporated Regiments that had already existed in England...
that operated the heaviest artillery weapons, formed into batteries of 4 mortars attached to each division
Division (military)
A division is a large military unit or formation usually consisting of between 10,000 and 20,000 soldiers. In most armies, a division is composed of several regiments or brigades, and in turn several divisions typically make up a corps...
, designated "V/nn" where nn = division number. From February 1918 they were reorganised and moved from divisional to corps
Corps
A corps is either a large formation, or an administrative grouping of troops within an armed force with a common function such as Artillery or Signals representing an arm of service...
control.
The weapon was dismantled for transport, requiring 4 carts for the barrel, base, carriage and ammunition.
In action, a heavy timber platform was constructed embedded in the ground, on which the mortar base was immovably secured. The mortar carriage sat on the base and could traverse. The mortar barrel and breech were mounted on the carriage which provided elevation
Elevation (ballistics)
In ballistics, the elevation is the angle between the horizontal plane and the direction of the barrel of a gun, mortar or heavy artillery. Originally, elevation was a linear measure of how high the gunners had to physically lift the muzzle of a gun up from the gun carriage to hit targets at a...
.
They were used in the "siege warfare" on the Western Front
Western Front (World War I)
Following the outbreak of World War I in 1914, the German Army opened the Western Front by first invading Luxembourg and Belgium, then gaining military control of important industrial regions in France. The tide of the advance was dramatically turned with the Battle of the Marne...
to destroy enemy strongpoints, bunkers and similar "hard" targets which were invulnerable to lighter mortars and field guns. The US Army handbook described it : "... the use for which it is primarily adapted is in the bombardment of strongly protected targets - dwellings, covered shelters, command posts, entrances to galleries, etc - or in the destruction of sectors of trenches, salients and the like.". Their effectiveness decreased late in the war as German policy changed to a lightly held frontline, hence decreasing available targets, and they became redundant when the war of movement resumed late in 1918.
Both the propellant charge appropriate for the required range and the bomb were loaded via the muzzle. Usually a Lee-Enfield rifle's bolt action mechanism was screwed into the breech. A special blank rifle cartridge was loaded and was triggered by pulling a lanyard
Lanyard
A lanyard is a rope or cord exclusively worn around the neck or wrist to carry something. Usually it is used where there is a risk of losing the object or to ensure it is visible at all times. Aboard a ship, it may refer to a piece of rigging used to secure objects...
, and fired into an igniter at the base of the mortar chamber, igniting the propellant charge and launching the bomb.
See also
- List of heavy mortars
- 240 mm Trench Mortar240 mm Trench MortarThe 240 mm Trench Mortar, or Mortier de 240 mm, was a large calibre mortar of World War I. An original French design, it was developed by Batignolles Company of Paris and introduced in 1915.-Service:...
French, US & Italian version - 25 cm schwere Minenwerfer25 cm schwere MinenwerferThe 25 cm schwerer Minenwerfer was a heavy trench mortar used by Germany in World War I. It was developed for use by engineer troops after the Siege of Port Arthur during the Russo-Japanese War of 1905 illustrated the usefulness of this class of weapon in destroying bunkers and fortifications...
Approximate German equivalent
External links
- Om den engelske 9,45-tommers skyttegravsmorter Per Finsted,(in Danish)
- Kevin Robert Keefe, British 9.45in Heavy Trench Mortar, Mark III. with specifications and photographs of model
- www.1914-1918.net The Trench Mortars Chris Baker