Armored trains were introduced during the fighting of the American Civil War (1861-1865) and practical use of such weapon systems gave rise to train cars carrying all sorts of munitions-delivering weapons. Such weapons evolved much during the World War 1 (1914-1918) period as any and all manner of artillery was sought. The value of railway guns was not lost on the major players of World War 2 (1939-1945) for they, too, invested in the field of railway guns for the new to be had in Europe. Such an investment was also aided by the expanding railway systems brought about by a modernizing European infrastructure which made far-off places now more easily accessible and, in turn, made railway guns that much more tactically useful/flexible.
For the French, a major player in both World Wars, experience in the Great War of 1914-1918 provided an excellent foundation for the operation and deployment of these specialist artillery pieces. This exposure to railway guns allowed the country to pursue ever-bigger and more durable types during the interwar period and improvements to individual components, such as braking systems and recoil absorption, made the French creations some of the best in the world for their time.
At the end of World War 1, the French military could count nearly 550 "big guns" in service but only a little over 100 examples were made available by the time of World War 2. The French Army had a good portion of the stock scrapped rather than modernize them through expensive programs. The 1940 stock of guns ranged from 164mm caliber models to the massive 520mm type. In-between these was the 240mm TAZ Modele 1893/96 (Colonies) of which eight were mobilized to fight the Germans during the critical 1939-1940 battles. The "TAZ" acronym in the name stood for "Tout-Azimuth" describing their particular mountings as "all-azimuth" so the gun could fire independently of the direction of the train car.
The 240mm TAZ Modele 1893/96systems utilized a 240mm caliber barrel of 40 gauge. The entire battery weighed 140,000 kilograms and transport was wholly by the existing French railway system (via drive locomotive). The weapon fired projectiles weighing 161 kilograms out to ranges of 22,700 meters at a muzzle velocity of 840 meters per second.
The guns were used actively until the German pressure forced their abandonment. Captured systems were taken over, and redeployed, by the Germans under the designation of "24cm K(E) 558(f)". At least three fell to them while an additional two were acquired from Italian conquests. The series served in Axis hands until the end of the war in 1945.