The Heavy Mortar 370mm ‘Filloux’ was a powerful and compact weapon, initially intended to be deployed in static coastal emplacements. Having been transported to the site, it would (in theory) be fixed in position, and thereafter left. However, following the initial fighting in 1914, the French Army was desperate to use whatever was available to bring heavy firepower to the enemy trenches. Thankfully, the ‘Filloux’ was equipped with two types of handling system: one for movement on railway wagons, the other for road transportation. Each had handling gantries, cranes and special rigs. The largest of the rigs was for the barrel, which would be slung under a wheeled gantry; the other elements would be similarly transported under smaller gantries.
Moving this colossal weapon was difficult enough, and then there was the problem of siting it in a strategically worthwhile location. This would begin with the excavation of a large one-metre deep hole, into which would be lowered the primary firing platform. A series of vertical spades attached to the base would absorb most of the mortar barrel’s recoil, which in turn would be assisted by the weight of the carriage (incorporating a basic recoil cylinder system connected to the trunnions). While this whole operation was both time-consuming and labour intensive, it was a necessary price if the French were to benefit from a heavy artillery presence in 1915 and 1916.