Canon de 120 mm modèle 1878
The Canon de 120 mm L modèle 1878 – was a French piece of siege and field artillery which was widely used during the First World War and despite its obsolescence, it was still in use by some nations during the Second World War. History. The Canon de 120 mm L modèle 1878 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, 240 mm) and two mortars (220 mm, 270 mm) were ordered by the  French Army. The mle 1878 was advanced for its time due to being built completely of steel instead of a steel liner and cast iron reinforcing hoops of the previous "Canon de 240 mm C mle 1870"-87. Design. The 120 mm L mle 1878 was a breech loaded gun with a de Bange obturator and used separate loading bagged charges and projectiles. It had a box trail carriage, two wooden spoked wheels with steel rims and an unsprung axle. The 120 mm L mle 1878 was lighter and more mobile than its heavier brother the Canon 155 mm L mle  1877. It had roughly the same range and rate of fire as the Canon 155 mm L mle 1877, but it fired a lighter projectile. The 120 mm L mle 1878 was classified as a "siege et de place" (stationary siege gun) for the defense and attack of Fortifications. In line with this mission, the carriage was tall because it was expected that its barrel would project out over a forts parapet and use its range to provide counter-battery fire against enemy artillery. First world war. 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 Western Front stagnated and trench warfare set in. Fortresses, armories, coastal fortifications, 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. An early drawback of the gun was that it involved considerable time to prepare a firing platform made of timbers before  use. An was then bolted to the platform and connected to the bottom of the gun carriage. Without it, the gun had no recoil mechanism and when fired the gun rolled back onto a set of ramps behind the wheels and then slid back into battery. In order to traverse the carriage had to be levered into position and due to its lack of recoil mechanism, it had to be re-aimed after every shot, which limited its rate of fire. An early modification to make the guns suitable for field use was the fitting of Bonagente grousers to the  wheels to improve balance and reduce ground pressure on soft ground. An added bonus was they slowed recoil and didn't require extensive site preparation to bring the guns into action. At the outbreak of WWI, there were 2,417 in reserve or at forts. Due to its light weight, good range, and heavy shell 120 were chosen to equip horse-drawn artillery units at the outbreak of the First World war in order to give them heavy artillery and they could be towed at . The end of the box trail could be attached to a limber for towing and each  gun was provided with a caisson for ammunition. For transport, the 120 mm L mle 1878 could be transported in one piece by a horse team in comparison to the Canon 155 mm L mle 1877 which needed to have its barrel removed from the carriage and transported separately. However, the barrel could be pulled rearward and fastened to the trail for transport. Experiments with motor traction during 1914 were successful and there was a requirement for 100 batteries to be motorized in 1915. Motorization promised speeds of and although mobile, the carriage was lightly built which negatively affected its  durability when used as a field piece. During the Second Battle of Champagne in 1915, 60% of the pieces never reached the front due to being damaged during transport and afterwards towing speed was restricted to . Second world war. At the end of the first world war, there were still 526 guns in French service. In 1939 there were 600 pieces in reserve and During the Second World War. A number equipped the forts of the Séré system of Rivières des Hauts-de-Meuse (Fort Troyon and Fort Liouville ) with another 92 in artillery regiments of the Maginot Line. A  number were also still in use with Belgium, Finland, Italy, and Poland. Ammunition. Types of ammunition available were: