De Bange 155 mm cannon

The '''De Bange 155 mm long cannon mle. 1877 (or more briefly the 155 L de Bange''') was the French artillery piece that debuted the 155 mm caliber in widespread use today. Although obsolete by the beginning of World War I, the 155 L was nonetheless pressed into service and became the main counter-battery piece of the French army in the first two years of the war.

Development and deployment
Drawing from the experiences of the Franco-Prussian War of 1870-1871, a French artillery committee met on 2 February 1874 to discuss new models for the French fortress and siege artillery. Among them was a piece in the 14 to 16 cm caliber range. After several meetings, on 16 April 1874 the committee settled on the 15.5 cm caliber. In the subsequent program-letter of the committee dating from 21 April, the caliber was for the first time expressed as 155 millimeters. (The other two calibers decided by this committee were the 120 mm fortress and siege cannon and the 220 mm mortar.) Three different 155 mm prototypes were tested in Calais in 1876. The winner was Charles de Bange's model, and the French government ordered the first 300 pieces in November 1877.

In common with the other de Bange cannons, the 155 L had a hooped steel construction with gain-twist rifling. In the 1877 conception, the cannon required a wooden platform from which to fire. Its recoil was absorbed simply by friction with the platform, and the 155 L had to be pushed back into position after every shot. Later, the model 1883 Saint-Chamond hydraulic brake was introduced. This was a separate piece of equipment that anchored the cannon's carriage to the firing platform and returned it into position after about 110 cm of recoil.

Of the approximately 1,400 pieces built, most were placed in France's numerous fortresses, most notably at Toul, Belfort, and Verdun (part of the Séré de Rivières system). In 1882, about 200 were retained for offensive operations as siege artillery. In this type of deployment, each gun was drawn by ten horses.

World War I
At the turn of the century the de Bange cannons were rendered obsolete by the newer quick-firing guns using the French 75 recoil system, in which only the tube recoiled. The 155 mm de Bange was then retained in forts and in reserve, the French army's doctrine at the time emphasizing mobility. The "75 for everything" had become its universal mantra for field artillery. On 2 August 1914, the French army had 1,392 pieces of 155 L de Bange, either in depots or in fixed positions; not a single one was part of the equipment of a mobile unit. On the eve of the war, a typical French army corps had 120 75-mm cannons, while its German counterpart had 108 77-mm, 36 105-mm, and 16 150-mm.

The first engagement of the 155 L was probably by the 8th Foot Artillery Regiment firing from place fortifiée d'Épinal during the Battle of the Mortagne on August 27. The first artillery duels of the war quickly convinced the French of their inferiority in heavy artillery relative to the Germans. Thus it was seen necessary to enhance the mobility of their 155 mm guns. In October 1914, a program was started to fit the 155 L wheels with a system of metallic soles and gutters articulated together (system known as cingoli or Bonagente wheel belts ), thus dispensing with the laborious construction of wooden platforms. The tracks added 800 kilograms to the gun's weight, but saved 5 tons of bedding material for the wooden platforms that otherwise had to be transported. They also lowered the time required to deploy from 5-6 hours to just one.

On November 27, each French army corps was endowed with a heavy artillery group. By November 30, 112 pieces of 155 L had already been mobilized for this purpose. In October-November 1915, a more formal organization was introduced, grouping the 155 L in mobile service in 30 heavy artillery regiments: twenty of these regiments were horse drawn (totaling 320 pieces of 155 L), while ten regiments used motorized tractors for transportation and had a mixture of 155 L and 120 L de Bange guns. By 1 August 1916, the number of 155 L guns in mobile service reached 738 pieces. The number of motorized 155 L guns increased from 40 in the end of 1915 to 128 in July 1917.

A significant improvement in combat capabilities was achieved by boosting the powder charge, made possible by the strong construction of the 155 L. The shells used before 1914 had a speed of 470 m/s and a range not exceeding 9800 meters. This increased to 561 m/s and gained 2,900 meters in range in 1915.

Starting in May 1916 the 155 L were progressively replaced by newer models of the same or similar caliber. The 155 L tubes were generally retired after they had 10,000 rounds through them. A number of replacement barrels were however manufactured starting in 1916. These were of somewhat simplified construction, with a constant-step rifling. Visually, the most distinctive difference between the old and new barrels is their lifting handle, which is longitudinally aligned with the barrel in the old ones but transversal in the new barrels. The introduction of quick-firing, replacement materiel for the 155 L, which was initiated by the First Stage of the Realization of the Heavy Field Artillery Program of May 30, 1916 was still not finished in November 1918. The field artillery of each French army corps still had a battalion of 155 L, model 1877 guns at this date.

Three 155 L were in the possession of the Romanian Army in 1915; this number increased to four by 1918. The battery served with the 1st Siege Regiment (Regimentul 1 Asediu) of Bucharest throughout the war.

Eighty 155 L were given by France to the Russian Empire, fifty in 1916 and thirty in 1917. The gun was also used by the Red Army during the Russian Civil War. For example, six 155 L were used by the 51st Rifle Division in their defense of Kakhovka in 1920. At the end of June 1937, 32 155 L guns were sent by the Soviets to the Republican forces during the Spanish Civil War, aboard the ship Santo Tome, which arrived at Cartagena. The Spanish formed 15 two-gun batteries with these, and kept two in reserve for training.

World War II
Some 305 pieces of 155 L were still equipping the French forts on 10 May 1940; of these, 168 were deployed in the Maginot Line and 137 in the smaller works in the South-East.

In 1940, during the Winter War, France donated 48 155 L cannons to Finland, as part of a larger artillery equipment help, but these arrived too late to take part in that conflict. The 155 L served however as the 155 K/77 during the Continuation War. All 48 guns were still in Finnish service in September 1941; the number of operational 155 K/77 pieces decreased to 42 by January 1944 and to just 19 by September of that year. The Finns used them with a 43.6 kg shell with a 5.7 kg explosive charge, attaining a range of 12.3 km. Four of the 155 L guns donated were converted to coastal guns under the designation 155/27 BaMk (De Bange Mk-lavetilla).