Since aircraft of the period were not yet capable of carrying large diameter bombs the burden of delivering heavy firepower fell on the artillery.

Rail transport proved to be the most practical solution because the problems of heavy weight, lack of mobility and reduced setup time were addressed.

[3] The carriages consisted of a large rectangular steel base, which was suspended on two six-axle railroad bogies manufactured by St. Chamond.

[2] These were the longest range guns available to the French and US Army during the first world war and although well regarded they were time-consuming to set up with 2–5 days of site preparation being required.

[3] Sections of the rail bed were also reinforced in front of and behind the carriage to provide a level surface for the gun.

[6] All six guns survived the Fall of France and three were given to the Italians who gave them the designation Cannoni da 340/45 Mod.

Three guns were used by the Germans under the designation 34 cm Kanone (Eisenbahn) in Wiegenlafette 674(f) and were employed by a Kriegsmarine coastal defense battery at Plouharnel near the port of Lorient.