World War II German Super-Heavy Siege Guns

As the outbreak of World War II approached, Nazi Germany ordered artillery manufacturers Krupp and Rheimetall-Borsig to build several super-heavy siege guns, vital to smash through French and Belgian fortresses that stood in the way of the Blitzkrieg. These ''secret weapons'' were much larger than the siege artillery of World War I and included the largest artillery piece of the war, the massive 8...