Karl-Gerat 040/041 Self-Propelled Siege Howitzer
The Gerat series of howitzers are the largest self-propelled guns to have ever seen military service.
Authored By JR Potts, AUS 173d AB; Content ©www.MilitaryFactory.com
The Karl-Gerat (040/041) (or "Karl device" in German) was a self-propelled siege howitzer designed and built by Rheinmetall in World War 2. The howitzer became the largest self-propelled gun ever built and used in combat. Despite its size and available firepower, the system had all the inherent weaknesses of all previous large-caliber cannon platforms to which its combat usefulness was questionable.
Hitler was always ready to invest resources into new weapon systems if they had great destructive potential and could terrorize his enemies. The V-2 rocket and the heavy water project that would have lead to an Atomic bomb were two other such projects. In 1936, the munitions designer and builder Rheinmetall made a proposal to the German High Command for a super heavy howitzer capable of destroying the defenses of the Maginot Line defending France from German invasion. On paper this was no easy feat for the defensive line stretching along the French eastern border between Germany and Italy was a formidable one and constructed based on French experiences garnered in World War 1.
This defensive line ranged between 20 to 25 kilometers deep and was built with a complex system of strong points including 34 turrets of 75-mm gun emplacements, concrete fortifications, 19 turrets of 50-mm motors, barricades, 61 machine gun turrets providing overlapping and concentrated fire, 17 turrets of 135-mm guns and the like. Hitler knew that war was coming and his first strike would be to the West. The order was given to build the 040 before Germany had officially committed to war but Hitler went ahead and attacked early when world events seemingly gave him the advantage. Thusly, the new howitzers were not made ready in time for the German Blitzkrieg against Poland and France. As it turned out, the French Army was not as formidable as their Maginot Line and the fortifications were quickly dispatched by standard German armor and infantry. Patton was once quoted as saying "If mountains and oceans can be overcome then anything man has made can be also be overcome". How true it proved for these French defenders.