Among the largest cannon used in the Civil War
Monumental in size, these two immense guns remain as sentinels ready to repel an attack on the Nation's capital. With their extended range and commanding location above the river, they were the key defensive feature of the fort. Perhaps because of their formidable weight, the guns (original armament of the fort) have not been moved since their installation in 1864.
Immobile as these huge guns may appear, a well drilled crew of 12 men could charge a gun with 40 pounds of black powder, load a 434-pound iron ball, 15 inches in diameter, and aim and fire once every 4 minutes.
Innovative technology in iron gun-casting made it possible to produce these 49,000 pdr. guns. They were named after Brig. Gen. Thomas J. Rodman, who perfected this new technology shortly before the Civil War.
These smoothbores were not noted for pinpoint accuracy. The three-mile range for such a large explosive projectile, however, was an impressive new defensive capability for the Civil War forts protecting Washington.