Break-in of the century: DNB

A unique challenge: open the vault door in the former Nederlandsche Bank

We confidently accepted the challenge to open a special vault door: the high-security vault door in a former branch of the Nederlandsche Bank in Arnhem. The new owner wanted to use the vault space. Unfortunately, the vault door, with a thickness of between 60 and 80 cm and with an unknown combination, was locked.

What was so unique about it?

Breaking open a vault at the level of the Nederlandsche Bank is actually never necessary. There is always an emergency door in case something goes wrong with the main vault door. A technician can then get into the vault room and open the main door from the inside. In this case, both doors were locked with all four combination locks. And the codes were no longer traceable. All the factory combinations had been tried to no result. Finally, Van den Hoogen Security was called in as the safe-opening specialist. Objective: open the vault without damaging it.

100 million possibilities

The combination locks were four-disc locks and indirectly driven with toothed gearing. This meant that turning the dial caused a lot of noise. And noise hinders feeling when manipulating. Moreover, the spindle of a numbered combination lock in a vault door of this thickness resists far more than that of a normal, thinner vault door. A four-disc numbered combination lock can be configured in 100 million ways -- for example: 5xR84 - 4xL51 – 3xR8 – 2xL91 -- and then closing to the right. Turning the (proper) combination once takes approximately a minute. Multiplied by the number of possibilities, it would take about 7000 days of 24 hours (38 years) to try all the combinations.

There wasn't that much time. So we decided to deploy a manipulation technique that the world's best security experts considered impossible for this type of lock. We gave ourselves two days and four hours. After that, it would take us no more than two days to drill a hole in the door in order to track down the combination. An alternative technique causing minimum damage.

A race against the clock and the lock

DAY 1

Master safecracker Wim van den Hoogen started the job, together with a few colleagues who could help and answer media questions. There was considerable media attention from TV Gelderland, SBS 6 and RTL 4. Wim was busy and didn't say much about the results until a clear CLICK could be heard in the upper disc code lock at around 4:15. After a few seconds, Van den Hoogen revealed: " the upper lock is released, I'm halfway there." The tension rose as he tried the code from the first lock on the second lock. No luck. Too bad. He had predicted this but, still, it was possible.

RTL4 Editie NL broadcast

SBS 6 broadcast

DAY 2

Van den Hoogen got busy early on the second day. The first two codes went relatively quickly. The third is more difficult. Technically, but also from the media visits that disrupted concentration. At a certain point, visitors were asked to leave the room and to watch quietly from a distance. After studying the measurement data from the other wheels, Van den Hoogen discovered a logical error that had shunted him onto a dead-end. An hour and a half later, he had succeeded in cracking the third and the fourth codes. Although the vault was expected to be empty, the opening was still an exciting moment. The door swung open and revealed an empty space of 6.5 x 6.5 m with blank walls. There was a slightly stale smell in the air that confirmed: money does, indeed, stink.

TV-Gelderland broadcast: It's open!