24 cm SK L / 40 " Theodor Karl " The 24 cm SK L / 40 " Theodor Karl " ( SK - Schnelladekanone ( quick loading cannon ) L - Länge ( with a 40 caliber barrel ) ) was a German railroad gun that served on both the Eastern Front ( World War I ) and the Western Front in World War I . Originally a naval gun , it was adapted for land service after its ships were disarmed beginning in 1915 . One gun saw service in the Belgian Army after the war . After Belgium ' s surrender in World War II , the Germans used that gun on coast - defense duties for the rest of the war . Design . Beginning in February 1915 , the five ships of the pre - dreadnought were decommissioned by the German Navy ( Kaiserliche Marine ) as obsolete , followed by the five ships of the in 1916 . Twenty - six of their " 24 cm SK L / 40 C / 94 " main guns were transferred to the Army . Eight to be used for coast defense by " Batterie S2 " at Sylt and " Batterie Hamburg " at Norderney , and the remaining eighteen were intended for the Western Front . 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 . The guns for the Western Front were mounted in " Bettungsschiessgerüst " ( firing platforms ) , which were portable mounts that could be emplaced anywhere after several weeks of labor to prepare the position . The " Bettungsscheissgerüst " rotated on a pivot at the front of the mount ; the rear was supported by rollers resting on a semicircular rail . It was generally equipped with a gun shield . The Germans were dissatisfied with the lengthy time required to emplace the " Bettungsschiessgerüst " and , on 1 July 1916 , decided to emulate the French and place the guns on railroad mounts ( " Eisenbahnlafette " ) to maximize their mobility and minimize the time required to emplace the gun . Four guns were removed from their mounts and tested at the Krupp Proving Grounds in Meppen beginning in December 1916 . Despite being able to fire in less than ten minutes , they were deemed unsatisfactory . A combination of the best of both methods was developed as the " Eisenbahn und Bettungsschiessgerüst " ( " E . u . B . " ) ( railroad and firing platform ) mount . The twenty - two remaining guns were placed on the new mounts . The " E . u . B . " could traverse a total of 2° 15 ' for fine aiming adjustments . It could fire from any suitable section of track after curved wedges were bolted to the track behind each wheel to absorb any residual recoil after the gun cradle recoiled backwards . It also had a pintle built into the underside of the front of the mount . Two large rollers were fitted to the underside of the mount at the rear . Seven cars could carry a portable metal firing platform ( " Bettungslafette " ) that had a central pivot mount and an outer rail . It was assembled with the aid of a derrick or crane , which took between three and five days , and railroad tracks were laid slightly past the firing platform to accommodate the front bogies of the gun . The gun was moved over the firing platform and then lowered into position after the central section of rail was removed . After the gun ' s pintle was bolted to the firing platform ' s pivot mount , the entire carriage was jacked up so that the trucks and their sections of rail could be removed . The carriage was then lowered so that the rear rollers rested on the outer track . Concrete versions were also used . It could have up to 360° of traverse . Ammunition . Ammunition on the " Eisenbahnlafette " and " E . u . B . " mounts was moved by means of an overhead rail from which a pair of shell tongs lifted up individual shells to be placed in the loading tray fixed to the breech . An extensible rail could raised and braced in place to allow the tongs to reach shells placed on the ground on in an ammunition car behind the mount . The gun had to be loaded at zero elevation and thus needed to be re - aimed between each shot . The " Theodor Karl " used two different shells , one armor - piercing and the other high - explosive , that both weighed . 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 that was rammed first . Combat History . The " Theodor Karl " was first blooded at the Battle of the Somme in October 1916 , where it performed well enough that another eight guns were transferred to the Army . One gun , assigned to " Battery 1011 " , participated in the Battle of Riga in September 1917 . One complete " Drh . L . C / 96 / 97 " turret from the armored cruiser was emplaced in the Forêt d ' Houthulst in 1917 , where it formed " Battery 1025 " - it was called " Turm Theodor Karl " . The two guns were removed from the turret at the end of 1917 and placed on " E . u . B . " mounts . Three " E . u . B . " guns were captured in Belgium in 1918 . Twenty " Theodor Karls " mounted on railroad cars ( either " Eisenbahnlafette " or " E . u . B . " mounts ) were destroyed after the Armistice . It is uncertain if the four railroad mounts were among those destroyed by the Allies . Four escaped destruction by the Military Inter - Allied Commission of Control because they were assigned to " Batterie Altona " on coast - defense duties at Wilhelmshaven . One gun survived in Belgian service after the war and was captured in World War II by the Germans and placed into service with " Railroad Artillery Battery ( Artillerie - Batterie ( Eisenbahn ) ) 674 " . It spent the war on coast - defense duties in the vicinity of Hendaye and Saint - Jean - de - Luz near the Spanish border with France , but its fate is unknown .