The Heavy Artillery Cannon was the largest towed artillery piece in the Great Steam War, usually towed by the more powerful vehicles, such as the Heavy Steam Tank. Its 660mm shells could completely demolish any known armor at the time. The gun was often used as a direct-fire anti-vehicle cannon to take down the massive vehicles of the Great Steam War, usually disabling even the largest ones. It was one of the first weapons in the Great Steam War to be equipped with a newly-invented recoil-suppression system. Despite this new technology, the gun would always need to have the stabilizers planted in the ground when it fired.