United States Bullion Depository - Construction and Security

Construction and Security

Below the fortress-like structure lies the gold vault lined with granite walls and protected by a blast-proof door weighing 22 tons. Members of the Depository staff must dial separate combinations known only to them. Beyond the main vault door, smaller compartments provide further protection. According to a Mosler Safe Company brochure:

"The most famous, if not the largest, vault door order came from the Federal government in 1935 for the newly-constructed gold depository at Fort Knox, Kentucky. Both the vault door and emergency door were 21-inches thick and made of the latest torch- and drill-resistant material. The main vault door weighed 20 tons and the vault casing was 25-inches thick."

The facility is ringed with fences and is guarded by the United States Mint Police. The Depository premises are within the site of Fort Knox, a United States Army post, allowing the Army to provide additional protection. The Depository is protected by layers of physical security, alarms, video cameras, mine fields, barbed razor wire, electric fences, heavily armed guards, and the Army units based at Fort Knox, including unmarked Apache helicopter gunships of 8/229 Aviation based at Godman Army Airfield, the 16th Cavalry Regiment, the 19th Engineer Battalion, formerly training battalions of the United States Army Armor School, and the 3rd Brigade Combat Team of the 1st Infantry Division, totaling 30,000 soldiers, with associated tanks, armored personnel carriers, attack helicopters, and artillery.

There is an escape tunnel from the lower level of the vault to be used by someone accidentally locked in.

For security reasons, no visitors are allowed inside the depository grounds. This policy has been enforced ever since the vault opened and the only exception was an inspection by members of the United States Congress and the news media on September 23, 1974 led by then Director of the United States Mint Mary Brooks.