Can art and cultural treasures be protected against brute force, as recently seen at the Louvre?
They can, says Peter Hohenstatt, head of development at Glasbau Hahn, a company that manufactures display cases for museums around the world. However, he adds, the available technical possibilities are often not fully utilized.

Mr. Hohenstatt, hopefully none of Glasbau Hahn’s showcases were smashed during the theft of Napoleon’s crown jewels at the Louvre?
No, those weren’t ours. However, we do have around 80 to 100 display cases installed in other rooms of the Louvre.

Why didn’t they use yours for the crown jewels?
If I remember correctly, the tender for the crown jewels’ display cases was issued in 2018. Glasbau Hahn did not participate in that tender—nor did another specialist one would have expected to. In the end, there was only one bidder, and they got the job. It was certainly not a company with sufficient experience in this kind of high-security showcase.

Still, they must have used special glass. How shatterproof can glass really be when brute force is applied?
Glass panes can offer an extremely high level of resistance. You can hit such a pane with a sledgehammer or even a large axe for minutes without breaking through. That’s because of the composition—burglar-resistant glass isn’t made of glass alone. It’s a composite product that also includes certain films or polycarbonates.

Polycarbonate—that’s what people commonly call acrylic glass, right?
Yes, exactly. It’s very difficult to break through such a composite product; it would take a lot of time. Professional burglars—like those who broke into the Louvre, who were certainly pros—would, of course, use tools specifically tailored for their task. They might first shatter the outer glass layer, then use a torch to soften the polycarbonate, reach the next layer of glass, and break through that as well. But even that takes time—and during that time, smoke detectors should go off. Perhaps instead they pried out the glass or opened the structure—if, for instance, a lock wasn’t properly secured, it could be knocked out with a hammer and chisel. To prevent that, the case must have an internal metal reinforcement. Making a display case truly mechanically secure is quite complex—and a job for specialists.

There’s now a new VdS standard for high-security showcases, established by the insurance industry. If that standard is met, could such a break-in still happen?
When standards are defined, tests determine how long a display case can withstand an attempted break-in. Using only the tools permitted by the test, it should not be possible to open a display case of the highest security class in less than ten minutes. But burglars keep getting more inventive, and there are ever more battery-powered tools available. If they bring along a device that didn’t exist when the standard was developed, they might get in faster.

So there’s a kind of arms race between those developing new security systems and the burglars?
Exactly—the crucial factor is time. That’s why it’s so important that an alarm is triggered as soon as someone starts trying to open a showcase. From that moment until the security team arrives, the burglar must not be able to reach the object inside—or at least not leave the room with it. Then the security system has done its job. In the Louvre’s case, the real vulnerability was that a window could be opened without security responding in time.

You’ve worked with many museums. Do similar security gaps exist elsewhere?
I don’t want to cause alarm—but yes, absolutely. It’s obvious that not every object can be protected against every possible break-in. Still, in many museums, there hasn’t been a thorough risk analysis to determine how much protection is appropriate for which objects. That’s something quite new in the field—only in recent years have institutions started to think about it seriously.

Is that because there have been several spectacular break-ins in recent years?
It’s always the spectacular cases that prompt change—but not only thefts. There have also been incidents where outgassing from materials destroyed objects. In other words, unfortunate events have pushed research forward in the museum sector. Rarely is there proactive, forward-looking research.

Still, it’s hard to ignore the bold museum break-ins of recent years—like the Dresden Green Vault or the theft of the giant gold coin from Berlin’s Bode Museum.
A proper risk analysis has to ask: who commits these crimes? Of course, some are acts of vandalism—but others target objects with political symbolism. Napoleon’s crown jewels, for example, are highly representative objects of the French state. So either the perpetrators wanted to damage the French state’s reputation for political reasons—in which case they probably would have destroyed the jewels—or someone wanted to possess them, perhaps a collector who commissioned the theft.

And then what—he just keeps them in a safe at home? He can’t exactly sell them.
Exactly. He’ll keep them in some vault, look at them from time to time, and take pleasure simply in owning them. There really are people who get a thrill from that—it’s not just a Hollywood trope.

Do such spectacular incidents affect your company’s business?
Not directly, because our project timelines are much longer. From order to installation takes about six months—and for public museums, the funding must first be approved. So we don’t see the kind of immediate reaction you might get in a supermarket during the pandemic, when toilet paper suddenly sold out. But with some delay, we do notice an increase in inquiries from museums wanting to do security checks or upgrades after such incidents.

Aren’t insurance companies also pushing museums to do that?
Of course, insurers will say: if you keep valuable objects in a high-security showcase, your premiums will be much lower than if they’re in a standard case. But many museum pieces aren’t insured at all—their value is simply too high. In the case of state museums, there are usually only government guarantees at the federal or state level. That’s why state criminal investigation offices are often involved when planning showcase security—but that only happens for a few publicly owned collections, often when an object is being loaned or exhibited somewhere new.

So if objects have been in a collection for a long time and stay there, no one really thinks about it?
Museum collections go back to the 18th century—or even earlier. If you look at the number of thefts in proportion to that long history, you can’t say the museum system has failed completely in terms of security. Still, there should also be a systematic risk analysis in Germany—like the one the French interior minister has now announced.

Written by Barbara Schäder.

Glasbau Hahn zum Raub im Louvre: Viele Museumsstücke sind schlecht gesichert | FAZ