24 cm Theodor Kanone ( E ) The 24 cm Theodor Kanone ( E – Eisenbahnlafette ( railroad mounting ) ) was a German railroad gun used during World War II in the Battle of France and on coast - defense duties in Occupied France for the rest of the war . Three were built during the Thirties using forty year - old ex - naval guns . Design . As part of the re - armament program initiated by the Nazis after taking power in 1933 the Army High Command " ( Oberkommando des Heeres - OKH ) " ordered Krupp to begin work on new railroad artillery designs , but they would take a long time to develop . Krupp pointed out that it could deliver a number of railroad guns much more quickly using obsolete guns already on hand and modernizing their original World War I mountings for which it still had drawings available . OKH agreed and authorized Krupp in 1936 to begin design of a series of guns between for delivery by 1939 as the Emergency Program ( " Sofort - Programe " ) . Three " 24 cm SK L / 40 C / 94 " guns originally used by the - and pre - dreadnought s were placed on new mounts patterned on the " E . u . B . " ( " Eisenbahn und Bettungsgerüst " - railroad and firing platform ) mount used by the same guns in World War I as the 24 cm SK L / 40 " Theodor Karl " . The new mounts lacked the under - carriage pivot and rollers used for the firing platform ( " Bettungsgerüst " ) in World War I as the Vögele turntable ( Drehscheibe ) completely replaced the old system . The turntable consisted of a circular track with a pivot mount in the center for a platform on which the railroad gun itself was secured . A ramp was used to raise the railway gun to the level of the platform . The platform had rollers at each end which rested on the circular rail for 360° traverse . It had a capacity of , enough for most of the railroad guns in the German inventory . The gun could only be loaded at 0° elevation and so had to be re - aimed for each shot . One obvious change made for land service was the placement of a large counterweight just forward of the trunnions to counteract the preponderance of weight towards the breech . This , although heavy , was simpler than adding equilibrators to perform the same function . All three guns were delivered in 1937 . Ammunition . The shells for this gun were loaded using a four - wheeled ammunition cart to move the shells and powder from the rear of the mount where it was hoisted from the ground or an ammunition car by the on - mount crane . It used the German naval system of ammunition where the base charge was held in a metallic cartridge case and supplemented by another charge in a silk bag which was rammed first . Combat history . Two " Theodors " equipped " Railroad Artillery Battery ( Artillerie - Batterie ( E . ) 674 " during the French campaign as it supported " XXV Army Corps " from Ettenheim during its passage of the Rhine River . From July 1941 they spent the rest of the war on coast defense duties assigned to " Batteries 664 " and " 674 " in the vicinity of Hendaye and Saint - Jean - de - Luz near the Spanish border with France , although sources differ on which guns were assigned to which batteries on what dates . Both batteries were able to retreat to Germany by 1 September 1944 after the invasion of Normandy in June 1944 , but nothing is known of their activities afterwards .