A Gun-howitzer is a type of artillery weapon that is intended to fulfill both the role of ordinary cannon or field gun, and that of a howitzer. It is thus able to convey both direct and indirect fire.
The first gun-howitzer was the French canon obusier of 19th century. The smooth-bore Canon obusier de 12 was a versatile weapon that quickly replaced both ordinary cannons and howitzers in French service, and became one of the basic types of artillery used by both sides of the American Civil War. Owing to their versatility, gun-howitzers gained prominence in the period leading to World War II as a more flexible weapon than ordinary howitzers and were adopted by armies of both the Allies (for instance the Soviet ML-20 152 mm M1937, the British Ordnance QF 25-pounder and the Axis (German 10.5 cm leFH 18).
The Ordnance BL 9.2-inch howitzer was a heavy siege howitzer that formed the principal counter-battery equipment of British forces in France in World War I. It equipped a substantial number of siege batteries of the Royal Garrison Artillery. It remained in service until the middle of World War II.
At the beginning of the war story Avanti Savoia!, several siege howitzers can be found in non-working condition.
The BL 9.2 Siege Gun is an emplacement featured in Battlefield 1 in the Battlefield 1: They Shall Not Pass expansion. It functions in a similar manner to the mortar through indirect aiming/firing and can be operated by any player.
With a maximum range between 225–250 meters, it can reach roughly halfway across the map. Its shells take about six seconds to arrive on target (compared with roughly two seconds for the Mortar). Three types of ammunition are available: high explosive, smoke, and gas.
The Siege Gun appears primarily on the map Verdun Heights, one at each team's deployment.
In Conquest, the siege gun is unusable at the start of the round, and covered by a tarp. It is made available if the team is given Elite kits (instead of the Behemoth usually provided), or if the enemy team captures all objectives at any point in the match.
In Operations, the siege gun appears along with the Elite kits in place of a Behemoth.
It also appears in Rupture in the third sector of Operations, at Notre Dame Ridge. Unlike those at Verdun Heights, this Siege Gun is easily reachable to the opposing side.
Two siege gun wrecks can be found on Monte Grappa near the San Rocco Church.
- The cannon is modeled after the BL 9.2-inch howitzer Mk I, as indicated by its shorter barrel.
- Prior to its introduction in "They Shall Not Pass", a siege howitzer can be found on Monte Grappa, but is currently unusable.