Mortier de 370 Filloux

French heavy 370-mm howitzer Mortier de 370 Filloux from the First World War.
History, development, service, specification, and pictures.

Mortier de 370 Filloux
A French 370-mm howitzer Mortier de 370 Filloux in position in the Ravin de la Baraquette west of Foucaucourt, September 1916.


The Mortier de 370 Filloux had its ori­gins in a specification regarding a coastal artil­lery gun able to produce plunging shells in order to cut the comparatively thinner armor of warship decks. By 1913 several of these short howitzers that fired at higher angles of elevation was manufactured, however in 1913 the 370-mm (14.57-in) gun was ready which continued to be afterwards the heaviest of all these French coastal artillery pieces.

To look at the Mortier de 370 Filloux it had been a sneakily compact gun. The truth is it had been incredible. It had initially been created for deployment in sta­tic coastal emplacements where – on paper certainly – it was to have been transported, emplaced and thereafter left.

What in fact occurred was that at that time after the first bloody battles of 1914, the French army hurried no matter what it could discover in the heavy artillery park towards the zones behind the front lines as a way to get some trench­-crushing potential, nevertheless minimal.
The good news is for the French, in the event the Mortier de 370 had been manufactured it included specific handling equipment of a pair of varieties. One was for deployment on railway carriages and the second one for street transportation and each received handling gantries, cranes and special rigs. The biggest of these rigs had been for the barrel, which was transported slung under a special wheeled gantry; the other loads had been moved slung in the same way. Overall there have been 3 primary loads with additional for the ammo as well as the numerous components.

If travelling the Mortier de 370 wasn’t enough, emplacing the howitzer had been even worse. The groundwork started with the excavating of a big hole into which was lowered the primary firing platform: this was built with a number of vertical spades on its bottom which were created to absorb a portion of the barrel recoil. Additional recoil had been consumed by the weighty carriage, which was connected to the platform and included a basic recoil cylinder system linked to the trunnions of the barrel. The emplace­ment and installation of all this required a considerable time and significant amounts of labor, however it was the price the French had to spend to be able to place some kind of heavy artillery right at the frontline during 1915-16.

As soon as in the frontline, the ammo for the howitzer had been bit by bit improved from the authentic armor-piercing pat­tern to a heavy blast-producing shell; the last of these projectiles had been introduced into action during 1917. There were a pair of these 1917 type projec­tiles, the bulkier weighing 489 kg (1,078 lb). However, with this the range was just 8,100 m (8,860 yards), which generated all the work required somewhat a waste of potential However for a long time it had been all that there was available, and the unlucky French gunners simply had to deal with it all.

Following 1918 the Mortiers de 370 Fil­loux had been put into reserve to be pulled out once again in the Phoney War of 1939-1940. There then happens to be some indecision regarding ex­actly where they were to be employed, and in the event the majority of them had been obviously wiped out by Luft­waffe strikes.

Specification Mortier de 370 Filloux


Mortier de 370 FillouxSpecification
Typeheavy howitzer
Calibre14.57 in (370 mm)
Length of barrel10 ft 3 in (3.31 m)
Weight between 63,934 lb and 66,139 lb (29,000-30,000 kg) in action
Elevation -6° to +65°
Muzzle velocity light shell 1,214 ft/s (370 m/s); heavy shell 1,037 ft/s (316 m/s)
Maximum range light shell 11,375 yards (10,400 m); heavy shell 8,860 yards (8,100 m)
Shell weight 911.6 lb (413.5 kg) or 1,078 lb (489 kg)
Production delivery1913
Total production?
Service delivery Western Front1915
at Verdun in May 19164

References and literature

The Illustrated Encyclopedia of Weapons of World War I (Chris Bishop)
An Illustrated History of the Weapons of World War One (Ian Westwell)
Die Geschichte der Artillerie (John Batchelor, Ian Hogg)

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