The €300 Million Wake-Up Call: Is Your Strongroom “Core Drill” Proof?

A sophisticated heist over the Christmas holidays in Gelsenkirchen, Germany, has sent shockwaves through the security industry and raised serious questions about modern strongroom protection. Between 27 and 29 December 2025, burglars bypassed traditional vault defences by drilling directly through a reinforced strongroom wall at a Sparkasse branch, gaining access to more than 3,000 safe deposit lockers.

Authorities initially confirmed losses exceeding €10 million, with later estimates suggesting around €30 million. Although the true value remains uncertain due to privately held contents. Lawyers representing victims have warned the total losses could potentially reach as high as €300 million, highlighting the scale of the breach and the risks faced by facilities relying on outdated physical protection.

How did they do it? They did not attack the door. They did not attempt to manipulate the lock. Instead, they used a tool commonly found on construction sites worldwide: a Diamond Core Drill.

At Associated Security Solutions, we believe incidents like this should be a wake up call. Understanding how core drill attacks work, and how modern strongroom design prevents them, is essential for anyone responsible for protecting high value assets. A question needs to be answered: is your strongroom core drill proof? Below, we explain the threat, examine verified real world examples, outline the EN 1143-1 CD classification, and provide practical guidance for UK businesses and individuals.

The Threat: What is a Core Drill Attack?

A core drill is not a standard hand tool. It is a powerful machine driven by a high-torque motor and fitted with a hollow, diamond-tipped bit. Rather than hammering or chipping material away, it cuts a neat, cylindrical core out of concrete and steel with terrifying efficiency. Legitimate tradespeople use core drills for plumbing, wiring, creating openings for HVAC vents, and even geological sampling.

Investigators believe the Gelsenkirchen burglars operated from an adjacent garage, boring through 60 centimetres of reinforced concrete to create an entry point roughly 40 centimetres wide, just enough for a person to crawl through.

Why criminals choose core drills:

- - Stealth: They are significantly quieter than explosives or jackhammers.
  - Cooling: Water cooling systems allow them to run for hours without overheating.
  - Precision: The attack is concentrated on a single, focused point, often bypassing vibration sensors if they are not specifically calibrated for the wall structure.

This Is Not An Isolated Method. Other Verified Examples

Gelsenkirchen is not an isolated anomaly. Across Europe, organised gangs repeatedly exploit neighbouring spaces and structural weaknesses.

- - Berlin tunnel case / Berliner Volksbank (2013): Burglars began digging a tunnel in early January 2013. They approached the strongroom from adjacent premises. Using a core drill, they penetrated the wall and stole at least €10 million. The perpetrators have not been caught.
  - Emmerich, Germany (2020): Three suspects drilled from an adjoining cellar into a customs office vault and made off with about €6.5 million. Investigators called the operation professionally planned.
  - Norderstedt / Hamburger Sparkasse (2021): Attackers rented an apartment directly above a Hamburger Sparkasse branch. They drilled through the floor and emptied hundreds of safe deposit boxes. Several customers later pursued civil claims against the bank over inadequate security.
  - Lübeck / Deutsche Bank (2024): Perpetrators carried out a late December raid similar to the Gelsenkirchen incident. They breached a Deutsche Bank vault and accessed more than 200 safe deposit boxes. The attack resulted in millions in losses and subsequent compensation claims.

These cases show a consistent pattern: Criminals find or create access points in neighbouring spaces. They deploy heavy drilling or tunnelling equipment to breach concrete and steel and then target large numbers of deposit boxes. Because many customers keep high value items without separate insurance, the total value taken often far exceeds standard insured limits for individual boxes.

The Solution: A Core Drill Proof Strongroom

To combat this specific threat, the security industry relies on the European standard EN 1143-1 (adopted in the UK as BS EN 1143-1). This standard grades the burglary resistance of safes, strongroom doors, and complete strongrooms.

Crucially, the standard includes an optional classification for specific attack methods. The most critical of these for modern high-value storage is the CD (Core Drill) designation.

What CD means in practice:

A standard strongroom wall, even one made of thick, reinforced concrete, can often be breached relatively quickly by a diamond-tipped bit. A CD rated strongroom, however, is a different beast entirely.

To achieve this rating, the strongroom must survive a brutal assault in an independent testing laboratory. Testers attack the wall using powerful diamond core drills with specific bit types and pressure loads, mirroring the equipment used by organised criminal gangs.

- - The Goal: The testers attempt to cut a hole large enough for a person (or a reaching arm) to pass through within a set timeframe.
  - The Defence: A core drill strongroom utilises advanced barrier materials, often proprietary matrices of high strength concrete, ceramic stones, and metal alloys. These are specifically designed and engineered to bind, blunt, or shatter diamond drill bits.
  - The Result: A CD rated wall delays or prevents a core drill from producing a man-entry breach within the certified test time.

Without CD protection a determined attacker can often make rapid progress.

Important for UK buyers: In the United Kingdom, this standard is strictly adhered to as BS EN 1143-1. Many reputable vault manufacturers and independent test houses certify CD performance. When you specify a CD rating, you are asking for proven, independently tested resistance to the tool used in the Gelsenkirchen incident.

“A CD-rated strongroom is not “impossible” to core drill, but it is designed and tested so that a diamond core drill cannot create a man-entry opening within the defined test time and tool limits specified in BS EN 1143-1.“

Why Alarm Systems Aren’t Enough

You might reasonably assume that alarms, CCTV and rapid response stop determined criminals. The recent pattern shows the limits of that assumption.

- - In Gelsenkirchen the burglary took place across the holiday period. A fire alarm briefly drew police, who initially left after finding no sign of forced entry, and attackers continued their work undisturbed after.
  - In other incidents, criminals use adjoining premises to operate inside the building envelope and bypass external sensors. Where alarms exist they have sometimes been circumvented, delayed or misinterpreted as false activations.

Electronic measures remain essential. They deter opportunists, speed responses, and support prosecutions. However, when attackers operate from neighbouring spaces or delays slow response times, the core drill proof strongroom wall becomes the final and most reliable line of defence.

Practical Advice for UK Businesses and Individuals

- - Check the grade, and check the ‘CD’ option: If you store high value assets, insist on BS EN 1143-1 certified strongrooms and doors with CD designation where available. Suppliers, independent certifying laboratories and insurers can confirm certificates.
  - Layered security: Combine CD rated physical barriers, monitored alarms with verified remote response plans, CCTV with tamper detection, and strong local procedural controls (for example, access control to adjacent spaces).
  - Audit adjacent spaces: Secure and monitor basements, parking garages and offices above or beside vaults. Criminals repeatedly exploit these neighbouring locations.
  - Review safe deposit policies: Many banks insure deposit boxes only up to modest sums. Customers with high value items should declare them and consider separate insurance. The Gelsenkirchen victims learnt this the hard way.
  - Engage independent advice. Use a qualified security consultant to match grade, CD options and response plans to your actual risk profile and insurance obligations.

How Associated Security Solutions Can Help

At Associated Security Solutions, we specialise in high security vaults and strongroom doors built to the rigorous BS EN 1143-1 standard.

We understand that a “standard” vault is no longer sufficient for modern threats. Our range extends from Grade II right through to Grade XIII EXCD (EX = tested resistance to explosive attack; CD = core drill resistance), ensuring we can match the physical security of your facility to your specific risk profile.

Why choose CD rated strongrooms from us:

- - Certified protection: proven resistance to diamond core drills under EN 1143-1 test conditions.
  - Options for every risk profile: grades covering standard commercial requirements up to Grade XIII EXCD for ultra-high-value use cases, such as international bullion storage or private safe deposit centres.
  - Bespoke design: we can integrate CD protection into custom room sizes and architectural configurations to suit your existing premises.
  - Expert integration: we advise on combining physical protection with alarms, CCTV, seismic/vibration sensors and operational procedures.
  - Peace of mind: if electronic alarms are defeated or response is delayed, a CD rated strongroom wall is your last and strongest defence.

If you store high value assets, relying on older vault specifications is a risk you cannot afford. Modern attackers use modern tools, and core drills are now a prominent weapon in the burglar’s toolbox. A CD rated strongroom is the most robust defence when electronic measures are defeated or delayed.

Do not wait for the next headline to upgrade your security. Explore our range of High Security Vaults and Strongrooms here: