It is believed two mortars were used during the initial French operations to retake Fort Douaumont during the Battle of Verdun, attracting four mortars for the final assault. The projectiles may not have been powerful enough to penetrate the roof of the fort. They also participated in the Somme Offensive and four were used in the Champagne region between August 1915-Feb 1916. Two were used during the Battle of Hartmannswillerkopf during 1915–1916.