Bank Vault


A bank vault is a secure space where money, valuables, records, and documents can be stored. Vaults protect their contents with armored walls and a tightly fashioned door closed with a complex lock. Vault technology developed in a type of arms race with bank robbers. As burglars came up with new ways to break into vaults, vault makers found innovative ways to foil them. Modern vaults may be armed with a wide array of alarms and anti-theft devices. Some nineteenth and early twentieth century vaults were built so well that today they are almost impossible to destroy. Buildings have been renovated around them. A restaurant in a restored bank building even features a dining area inside the indestructible vault. These older vaults were typically made with steel-reinforced concrete. The walls were usually at least 1 ft (0.31 m) thick, and the door itself was typically 3.5 ft (1.1 m) thick. Total weight ran into the hundreds of tons. Today vaults are made with thinner, lighter materials that, while still secure, are easier to dismantle than their earlier counterparts.





By the 1920s, most banks avoided using safes and instead turned to gigantic, heavy vaults with walls and doors several feet thick. These were meant to withstand not only robbers but also angry mobs and natural disasters. Despite the new security measures, these vaults were still vulnerable to yet another new invention, the cutting torch. Burning oxygen and acetylene gas at about 6,000°F (3,315°C), the torch could easily cut through steel. It was in use as early as 1907, but became wide spread with World War I. Robbers used cutting torches in over 200 bank robberies in 1924 alone. Manufacturers learned to sandwich a copper alloy into vault doors. If heated, the copper alloy melted and flowed. As soon as the burglar removed the heat, the copper resolidified, sealing the hole. After this design improvement, bank burglaries fell off and were far less common at the end of the 1920s than at the beginning of the decade.


A wanted poster of John Dillinger.
A wanted poster of John Dillinger.

Born June 22, 1903 in Indianapolis, John Dillinger was raised by his sister and stepmother. In 1924 he was arrested for attempted robbery and sentenced to 10-20 years in prison. Confinement trained Dillinger as a criminal and leaving prison in 1933, he carried a map of prospective robbery sites. In three weeks Dillinger robbed 10 banks in five states. Known as "Gentleman Johnnie," he was pleasant and often flirtatious during robberies. The press played Dillinger up as a brilliant, daring, likeable individual, beating the banks that foreclosed on helpless debtors.

Other criminals joined Dillinger, forming the Dillinger Gang. Banks were cased and robberies were timed. The heist was abandoned—no matter what—after a certain amount of time had passed. Getaways were also planned precisely: street lights were timed with back roads and alternate routes noted in the plans. Often, the gangsters didn't race out of town, they casually motored through back roads. FBI director, J. Edgar Hoover increased the reward for Dillinger and issued agents shoot to kill. The Dillinger pursuit was the largest manhunt in the country's history.

In 1934, Dillinger's friend—Anna Sage—agreed to betray Dillinger. On July 22, 1934, Sage, Dillinger, and Dillinger's girlfriend Polly Hamilton attended a movie on Chicago's North Side where Federal agents gunned Dillinger down. Following his death, the FBI press announced Dillinger was shot after resisting arrest and attempting to draw a pistol. Other members of Dillinger's gang were incarcerated or killed in shootouts with police. The reign of John Dillinger and his gang had come to an end. However, Dillinger's exploits earned him a lasting place in American crime history.

Materials used in vaults and vault doors have also changed as well. The earlier vaults had steel doors, but because these could easily be cut by torches, different materials were tried. Massive cast iron doors had more resistance to acetylene torches than steel. The modern preferred vault door material is actually the same concrete as used in the vault wall panels. It is usually clad in steel for cosmetic reasons.

Raw Materials

Vault walls and doors are comprised mainly of concrete, steel rods for reinforcement, and proprietary additives to give the concrete even more strength.




The Manufacturing

The panels

The door

The lock


Quality Control

Quality control for the vault industry is overseen by Underwriters Laboratory, Inc. (UL), in Northbrook, Illinois. Until 1991, the United States government also regulated the vault industry. The government set minimum standards for the thickness of vault walls, but advances in concrete technology made thickness an arbitrary measure of strength. Thin panels of new materials were far stronger than the thicker, poured concrete walls. Now the effectiveness of the vault is measured by how well it performs against a mock break-in. Manufacturers strive to make products that repel attacks for a certain number of minutes. A UL Class 1 vault is guaranteed to withstand a break-in attempt for 30 minutes, a Class 2 for 60 minutes, and a Class 3 for 120 minutes. UL's workers attack sample vault walls and doors with equipment that is likely a burglar could carry into a bank and use. This usually includes torches and demolition hammers. If the UL worker can make a hole of at least 6 × 16 in (15.24 × 40.64 cm) in less than the set time, that particular part has failed the test. Manufacturers also do their own testing designing a new product to make sure it is likely to succeed in UL trials.


The manufacturing process itself has no unusual waste or byproducts, but getting rid of old bank vaults can be a problem. Newer, modular bank vaults can be moved if a bank closes or relocates. They can also be enlarged if the bank's needs change. Older bank vaults are quite difficult to demolish. If an old bank building is to be renovated for another use, in most cases a specialty contractor has to be called in to demolish the vault. A vault's demolition requires massive wrecking equipment and may take months of work at a large expense. At least one company in the United States refurbishes old vault doors that are then resold.

The Future

Bank vault technology changed rapidly in the 1980s and 1990s with the development of improved concrete material. Bank burglaries are also no longer the substantial problem they were in the late nineteenth century up through the 1930s, but vault makers continue to alter their products to counter new break-in methods.

At issue in the twenty-first century is a powerful tool called a "burning bar" or "thermic torch." Burning liquid oxygen ignited by a oxyacetylene torch, this bar burns much hotter than an acetylene torch, getting up to 6,602-8,006°F (3,650-4,430°C). The torch makes a series of small holes that can eventually be linked to form a gap. In the future, the vault manufacturing industry will likely come up with a means to combat the burning bar. Then perhaps criminals will find a more powerful tool, and the industry will change its products again. Vault manufacturers work closely with the banking industry and law enforcement in order to keep up with these advances in burglary.

Where to Learn More


Steele, Sean P. Heists: Swindles, Stickups, and Robberies that Shocked the World. New York: Metrobooks, 1995.

Tchudi, Stephen. Lock & Key. New York: Charles Scribner's Sons, 1993.


Chiles, James R. "Age-Old Battle to Keep Safes Safe from 'Creepers, Soup Men and Yeggs.'" Smithsonian (July 1984): 35-44.

Merrick, Amy. "Immovable Objects, If They're Bank Vaults, Make Nice Restaurants." Wall Street Journal (5 February 2001): Al.

Angela Woodward

Also read article about Bank Vault from Wikipedia

User Contributions:

George Wells
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May 17, 2006 @ 12:12 pm
your article about the use of copper in vault doors is not strictly accurate .

Copper (and other metals) do not defeat the torch attack by melting and then re-solidifying but by dissipating heat faster than the torch can supply it . Even though copper's melting point is way below the maximum temperature of the torch ,its conductivity is so high that dissipates away from the flame point before it can melt .

Some manufacturers have also very sucessfully incorporated aluminium alloy slabs in to vault doors and highgrade safes for the same reason .

Other wise your article is an excellent condensed explanation of bank security essentials .
Donavan A. London
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Aug 22, 2009 @ 10:22 pm
My name is Donavan A. London and the the FBI and Agent Michael Moorehart accused me of stealing a group of American Express Traveler's Cheques from a SAFE that he claims was in the the Resolution Trust Warehouse in August of 1993. I sincerely need this information to clear my name. I obained his report and the FBI files via the Deparrtment of Justice and court files of the 262nd Distric Criminal Court, and there are no crime scene photos, no fingerprint evidence, no physical description of the SAFE, and shipping manifest to very if a SAFE was ever shipped or delivered there. I need a written confirmation to verify if a SAFE was built inside this warehouse in 1975 (the year the building was built) and copy of the floor plan to prove that the FBI and their Agent Fabricated the Evidence to charge me with felony theft. Please respond in writing in (10) business days. Again, this is a written FREEDOM OF INFORMATION REQUEST. Has a VAULT ever been built INSIDE A OFFICE WAREHOUSE BUILDING IN HOUSTON,TEXAS?


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