1. They Were Invented as a Result of the Gold Rush
At least in the U.S., bank vaults as we know them today emerged during the Gold Rush of 1849, when unsuccessful prospectors gave up on finding their gold in the ground and decided to get it the easy way — by robbing a bank. At that time, banks used safes to protect their goods, and bank robbers took to heaving these out the window, hauling them off, and breaking them open in a secure location. Banks quickly decided they needed a secure solution that couldn’t be carried off by a determined thief. As a result, safes got ever larger and heavier until, by the 1920s, most banks were using huge, built-in vaults, with walls and doors that were several feet thick.
2. There’s a Technological Arms Race With Burglars
Of course, for every genius who can invent a lock, there’s another one who can learn to pick it. That sort of technology arms race is ever-present in bank security.
Enterprising burglars have cleverly used gunpowder, nitroglycerin, and acetylene torches to pry open the tiny vulnerabilities each new bank vault provided. Today’s most secure bank vaults include more technology than ever, including things like heat sensors, motion detectors, and alarms. The very most secure vaults even include things like 22-ton vault doors, machine-gun wielding guards, three foot keys, and robots. When you’re guarding trillions of dollars, you can’t be too careful.
3. But They’ve Stuck With a Clever and Innovative Type of Lock
When bank robbers learned to blast through safes with key locks, inventor Linus Yale Jr. introduced a combination lock. But it wasn’t long before burglars learned to drill holes in the lock’s case and peer inside at the gears to open the lock. And, of course, the simplest way to get into any lock is simply to hold the bank manager hostage until he agrees to open it. So, a man named James Sargent came up with a combination lock that wouldn’t open until a set number of hours had passed. Time locks and time delay locks are still used in bank vaults as theft deterrents. Of course, for those who work at the bank, not being able to open the vault when you want or need to can occasionally prove to be most inconvenient.
4. They Are Built to Withstand *Almost* Anything
Although the latest bank vaults are built to be disassembled more easily (while still being ultra-secure), historically, bank vaults were built to last. Forever. As a result, some of them will survive almost anything. Even a nuclear blast. In fact, it was two Mosler bank vaults at the Teikoku Bank — and only those two bank vaults — that were left standing after Hiroshima was hit by an atomic bomb in 1945. In 1957, the U.S. also blasted a bank vault during nuclear testing in Nevada. The 37-kiloton nuke merely loosened the vault’s trim.
5. But People Get Through Them Anyway
Most bank robbers don’t even bother with the bank’s vault; according to the FBI, the vast majority of crimes happen at the counter. Of course, that isn’t to say that there aren’t a few clever criminals who make carefully planned attempts against a bank vault’s security features.