Although the majority of combatants had heavy field artillery prior to the outbreak of the First World War, none had adequate numbers in service, nor had they foreseen the growing importance of heavy artillery once the Western Front stagnated and trench warfare set in. Besides land mines, machine guns and trenches, barbed wire was a persistent threat to attacking infantry. Often barbed wire was used to channel attackers away from vulnerable areas of a defenders trenches and funnel attackers into predefined kill zones where overlapping fields of machine gun fire could be brought to bear. Rows of barbed wire could also be used to delay attackers allowing defenders time to man their trenches and to hold attackers at a safe distance to allow defenders to call in defensive artillery fire. What was needed to overcome the deadlock and give attackers an advantage was light, portable, simple, and inexpensive heavy firepower. A way to provide this was by designing a series of heavy trench mortars which could be brought to forward area trenches to launch heavy, short ranged preparatory bombardments to clear obstacles and neutralize enemy defenses.
Design
The Albrecht mortars came in a number of lengths and diameters each with their own projectiles. They consisted of a muzzle loadedsmooth bore barrel built from wooden staves and wound with galvanized wire for reinforcement. The base of the mortar was a large wooden block and there was a crescent-shaped adjustable metal stand with a hand wheel to adjust elevation.
Ammunition
The propellant and projectiles were loaded separately and the projectile was a simple metal can with a reinforced wooden base and a wooden lid with handle. The projectile was filled with explosives and metal fragments. Range was controlled by a combination of varying elevation and amounts of propellant. Projectiles weighed from for the 25 cm, to for the 35 cm, and for the 45 cm model. Accuracy, velocity, and range were all considered to be poor. The early projectiles also had poor aerodynamics, so later projectiles became more conical in shape. Due to poor aerodynamics, the projectiles sometimes fell on their side instead of their nose so a time fuse was used instead of an impact fuse. The slow-moving projectiles were given the nickname of "coal buckets" by the French.
