24 cm Theodor Bruno Kanone ( E ) The 24 cm Theodor Bruno 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 . Six were built during the Thirties using fifty 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 - Programm " ) . Six ancient " 24 cm K L / 35 C / 88 " guns originally used by the Odin class coast defense ship ( " Küstenpanzerschiff " ) that had equipped " Batteries S1 " at Sylt and " Bremen " at Norderney after those ships were disarmed in 1916 were placed on new mounts beginning in 1937 . The gun could traverse only enough on the mount itself for fine corrections ( the exact amount is disputed among the sources ) , coarser adjustments had to be made by turning the entire mount on the Vögele turntable . The turntable ( " Drehscheibe " ) 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 . All six guns were delivered by 1939 . 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 . During the Battle of France " Theodor Brunos " equipped " Batteries 664 " ( 2 guns ) , " 721 " ( 1 gun ) , and " 722 " ( 2 guns ) . Their only known activity was when " Battery 721 " bombarded French casemates in the Vosges during June in support of the " Seventh Army " . From July 1941 two guns spent the rest of the war on coast defense duties assigned to " Battery 664 " in the vicinity of Hendaye and Saint - Jean - de - Luz near the Spanish border with France although sources differ on their arrival date . " Battery 664 " was able to retreat to Germany by 1 September 1944 after the invasion of Normandy began in June 1944 , but nothing is known of its activities afterwards . " Battery 721 " transferred its one gun to " Battery 722 " sometime prior to June 1941 when the latter mustered four " Theodor Brunos " . " Battery 722 " defended Cherbourg from 1941 to 1944 until being destroyed when the Americans captured the port on 30 June 1944 .