Obusier de 400 mm modèle 1915/1916

Obusier de 400 mm modèle 1915/1916
Gun in transport position
General Information
Military designation:	Obusier de 400 mm modèle 1915/1916
Manufacturer designation:	Compagnie des forges et aciéries de la marine et d'Homécourt Saint-Chamond
Manufacturer country:	France
Development year:	1915
Production time:	1916 to 1918
Number of pieces:	8 modèle 1915 4 modèle 1916
Weapon Category:	Railway artillery
Technical specifications
Pipe length:	10.65 m
Caliber :	400 mm
Caliber length :	25th
Number of trains :	120
Twist :	7 ° right
Cadence :	0.18 rounds / min
Elevation range:	15 ° to 65 ° degrees
Side straightening area:	12 °

The Obusier de 400 mm modèle 1915/1916 ( German  400 mm howitzer model 1915/1916 ) was a French railroad gun on a cradle mount that was used during the First World War . It was intended to destroy enemy fortifications. It was the largest caliber used by the French artillery .

A total of twelve guns were made, eight in 1915 as "modèle 1915" and then another four in autumn 1918 as "modèle 1916".

The first delivered howitzers were used to fight the German positions during the Battle of Verdun , the Battle of the Somme and then in the battles of Reims from 1916 to 1917. The four copies of the "modèle 1916" were only ready for use shortly before the end of the war and were therefore little used. At the beginning of World War II mobilized again, they had to after the armistice of Compiegne to the armed forces to be delivered, unless they already German troops had not fallen into the hands.

Mission concept

Two months after the start of the First World War, the war of movement in France and Belgium turned into a war of positions , which became a kind of gigantic siege . The heavy artillery took on an increasingly important task here. Since France had to equip the long front with enough artillery, they resorted to naval and coastal artillery, among other things, and thus created the "Artillery lourde à grande puissance - ALGP" (artillery of great effect).

On July 22, 1915, at the request of the High Command, the War Ministry ordered eight 400 mm cannons. They were intended to fight the more distant German fortifications. They also wanted something that was equivalent to the German fat Bertha , who had successfully defeated the forts of Liège and Maubeuge (→ Siege of Maubeuge ) and the Fort de Manonviller .

Since such guns could not be made so easily, it was decided to use tubes from battleships that had already been decommissioned.

In view of the considerable mass of the pipe, which far exceeded the load-bearing capacity of horse-drawn carts and even large artillery tractors, the only choice left for the designers was to install a carriage on a special railroad car. Instead of using brakes to absorb the recoil, a hydraulic system was used.

The result was an expensive weapon (mainly because the raw materials were missing), hard to bring the rail network depends in position (it took two days to build the shooting platform, set up plus one hour after the gun), with a low cadence , an only mediocre muzzle velocity and insufficient elevation range, but with a very good precision and above all with great effectiveness in the destruction of fortified works.

Fabrication

For technical reasons it was not possible to manufacture the pipes within a reasonable period of time. In order to carry out the order, the "Compagnie des forges et aciéries de la marine et d'Homécourt" (better known under the name of the production facility Saint-Chamond ) bought the 340 mm modèle 1887 cannons of the decommissioned standard liner Brennus and the already decommissioned coastal armored ships Valmy and Jemmapes used. Of the available barrels, six were reamed to a caliber of 400 mm in 1915 and three at the beginning of 1916. Of these nine existing pipes, eight were placed in a weighing carriage and placed on special railway wagons. The carriage lay on two bogies, of which the front had six and the rear four axles. The ninth pipe was used for experimental purposes at the Gâvres shooting range .

A second order was placed in January 1917. It comprised four guns and three spare tubes. The plant in Saint-Chamond used the tubes of the Canon de 340 mm / 45 modèle 1912 , which were intended for the painted battleships of the Normandy class . Both models had the same properties and used the same bullets. In order to compensate for the barrel wear, boring to 415 mm was planned - if necessary - the guns were not used intensively enough, and this measure was not taken.

organization

The howitzers were set in four batteries in 1916 and six in 1918 . Each of the armies was assigned two guns. A train of eleven wagons with a total length of 260 meters was required to operate each of the guns. It consisted of the locomotive , the gun car, an equipment car, a platform car, a cartridge car, the personnel car and the car with the grenades, each of which carried twelve projectiles.

Each battery was commanded by a captain to whom a lieutenant and 125 men were subordinate.

Calls

First World War

Gun fired in the Harbonnières gorge on June 29, 1916 during the Battle of the Somme

The first use of one of these guns occurred in the last days of preparation for the Battle of the Somme. On June 30, 1916, the road at Morcourt was destroyed and the fortified villages of Herbécourt , Estrées and Belloy-en-Santerre razed to the ground.

Two guns of the 77th battery of the 3rd foot artillery regiment were set up in the course of the French offensive off Verdun on October 21, 1916 near Baleycourt to bombard Fort Douaumont and Fort de Vaux . The bombardment of Fort Douaumont began on October 23, at which a total of 15 shells were fired, six of which penetrated the roof of the fort. The first exploded in the medical casemate , another in the main aisle, three others in the casemates of the barracks and a last one in the pioneer depot. The latter caused a severe fire that forced the German occupation to abandon the fort, which was occupied by the French the next morning. Fort de Vaux was reached by French raiders in the early morning of November 3rd, found abandoned and reoccupied by other forces. The planned bombardment therefore no longer took place.

During the Battle of the Aisne , the guns were used in preparation for the French offensive near Reims , where the Fort de Brimont and the towns of Witry-lès-Reims and Berru were shelled . The same applied to the tunnels and shelters in Mont Cornillet and in the "Nameless Mountain". On May 20, 1917, a 400 mm shell, which had been fired from Mourmelon-le-Petit , struck the air shaft of a protective tunnel in Mont Cornillet and exploded in the gallery. 414 German soldiers were killed.

Memorial plaque for the 414 fallen at Mont Cornillet

In August 1917 four of the howitzers were used in support of the French offensive near Verdun on the left bank of the Meuse. The destination was the Crown Prince Tunnel at Cumières-le-Mort-Homme.

Another deployment took place on October 23, 1917 during the attack on La Malmaison , in which the German shelters in the quarries were shot at.

Second World War

In 1939, the 400mm howitzers were reactivated and combined into batteries. The railway guns were assigned to the "heavy railway artillery" (Artillerie lourde sur voie ferrée - ALVF) and turned off to the army artillery. They served to strengthen the Maginot Line in Alsace and Lorraine and took the positions assigned to them. However, due to a lack of suitable targets, they were not used anywhere. By June 1940, several of the howitzers fell into the hands of the German troops. After the armistice, the remainder were handed over to the Wehrmacht. They were then adopted as the "40 cm howitzer (railway) 752 (f)". Two batteries (693 and 696) with three guns each were installed and used during the siege of Leningrad . Nothing is known about the whereabouts of the guns.

Further technical data

• Weight of the gun without carriage: 47,500 kg
• Total length: 19.06 m
• Firing range: 13 to 14 km
• Shot power: 1000 shots (theoretical)

ammunition

There were three types of ammunition available:

• Explosive grenade made of cast iron "mle 1915": weight 890 kg (including 72.5 kg of explosives)

Detonator with a delay of up to 0.35 sec.

Propellant charge

74 kg BM13 - muzzle velocity: 465 m / s - range: 15.1 km

46 kg BM9 - muzzle velocity: 385 m / s - range: 11.98 km

36 kg BM9 - muzzle velocity: 330 m / s - range: 3.58 km

• High explosive grenade made of steel with reinforced point "mle 1915 type D": Weight 641 kg (including 180.2 kg of explosives)

Impact fuse "30 SM mle 1878/81 M1915"

Propellant charge

66.3 kg BM11 - muzzle velocity: 530 m / s - range: 16 km

39.5 kg BM7 - muzzle velocity: 420 m / s - range: 12.87 km

29 kg BM7 - muzzle velocity: 345 m / s - range: 10.2 km

• Reinforced high explosive grenade made of steel: weight 900 kg (including 90 kg explosives)

Delay detonator "mle 1915 type C" up to 0.35 sec.

Propellant charge

74 kg BM13 - muzzle velocity: 465 m / s - range: 15.1 km

74 kg BM13 - muzzle velocity: 465 m / s - range: 15.8 km

36.5 kg BM9 - muzzle velocity: 330 m / s - range: 9.58 km

function

Diagram: gun in loading position

Since the tubes were ship guns that were not intended for use in the upper bracket group , the trunnions were moved relatively far forward (also to relieve the leveling machines). This led to problems when used as a howitzer with the intended tube elevation of 65 °. So you had to dig a pit under the carriage, into which the lock could swing if the pipe was raised by more than 45 °. The pipe itself was stored rigidly in a pipe cradle. The front bogie of the carriage was jacked up on the rearmost axle, the rear chassis itself was blocked by a spur in a dug pit and thus absorbed the recoil.

Footnotes

1. ↑ Général Guy François: Les canons de la victoire 1914–1918 (= Les matériels de l'armée française. No. 4). Volume 2: L'artillerie lourde à grande puissance. 2008, ISBN 978-2-35250-085-8 (new edition 2015, ISBN 978-2-35250-408-5 ).
2. ↑ Alexander Schwencke, Martin Reymann: battles of the world war. Part 2. Volume 14: The tragedy of Verdun 1916 - The battle for Fort Vaux. P. 118 ff.

literature

• Stéphane Ferrard: France 1940. L'armement terrestre. ETAI, Boulogne 1998, ISBN 2-7268-8380-X .

Web links

• Canon de 400mm modèle 1916 à berceau. In: Regarder sans toucher
• Obusier de 400mm sur affut truc. In: Forest
• Le fort de Douaumont. In: Les Français à Verdun 1916
• L'obus de 400 mm. In: Ligne Maginot
• Base documentaire artillery (Bas'Art)