The GUSTAV and DORA were the names given to two of Germany s 80 cm ultra – heavy railway guns. Developed in the late 1930s, these mammoth artillery pieces were built principally to help destroy the main forts along the MAGINOT LINE. These twin giants weighed almost 1,350 tonnes and could fire shells weighing seven tonnes to a range of almost thirty miles. Similarly, the THOR siege mortar was also a giant on the battlefield, sporting a 60 cm caliber barrel, six mile range and weighing in at over 120 tonnes. Although these guns were not ready to be used in the Battle for France, they were later used against the Soviet Union at the siege of Sevastopol to good effect. This fascinating film shows these amazing feats of engineering in their full glory through original archive footage, from their initial design and construction to testing and eventual deployment against the enemy.