Proof Steel

A forty-eight-inch section of armor plate, seventeen and a half inches thick, bears a hole made by a Mark 8 sixteen-inch armor-piercing shell weighing two thousand seven hundred pounds fired at point-blank range. Such firing was known as proofing and was used to test armor against different projectiles, while the military also used proofing to test the integrity and reliability of a weapon's barrel, breech, and recoil systems. This ten-ton piece of proof steel originally formed part of a larger proof steel wall at the Naval Support Facility in Dahlgren, Virginia. The Coastal Defense System used a variety of projectiles to protect the coastline, including sixteen-inch armor-piercing shells like those used in Battery Smith at Fort Miles. By World War Two, Coastal Artillery color coding for a sixteen-inch shell used a black base and yellow nose, while a one-inch red band identified a shell from the U.S.S. Missouri and an additional blue band marked it as an inert shell for training or display. Each shell weighed two thousand seven hundred pounds, and the sixteen-inch guns that fired them had a range of twenty-seven and a half miles and used six hundred sixty pounds of powder to send a shell that distance.

Delaware · United States