With the CRITIS umbrella law, integrated perimeter security is becoming an even greater priority for companies, public authorities and operators of critical infrastructure. The requirements follow a comprehensive ‘all-hazards’ approach: the aim is to better defend against natural disasters, sabotage, human error, terrorist attacks and other security-related incidents, and to limit their consequences more effectively.
For operators of critical infrastructure, this means above all that existing security concepts must be reviewed and technical protective measures reassessed. Physical perimeter security plays a central role in this – and it starts at the fence.
The fence as a visible boundary
Fences are far more than just structural boundaries. They are an essential component of holistic security concepts. Their primary function is, first and foremost, to prevent unauthorised access. However, against the backdrop of the CRITIS umbrella law, aspects such as tamper resistance, durability and the integration of other perimeter security components – such as access roads, gates, sensors and cameras – are also coming into focus. “A standard off-the-shelf fence remains, first and foremost, a standard off-the-shelf fence,” sums up Claus Heidrich, Head of Marketing and Sales at fencing and gate specialist Berlemann. “The actual vulnerabilities always arise from the specific security requirements and the respective attack scenarios.”
As security requirements increase, so too does the technical complexity of fence construction. Operators, particularly those responsible for critical infrastructure, should pay close attention to the quality, design and maintenance of the systems used. “In an emergency, it is not the visual appearance of a fence that counts, but its structural and material strength,” says Heidrich.
According to him, the thickness of the posts, the fastening systems used, sufficient wire thicknesses and corrosion-resistant coatings are therefore also crucial: “A fence must function reliably for many years, even when exposed to the elements or under heightened security requirements.”
It’s all about the joints
Kai-Uwe Grögor, Managing Director of the Gütegemeinschaft Metallzauntechnik e.V., addresses the issue from a quality assurance perspective and points out that double-bar panels dominate the modern fencing systems sector. However, in his view, the quality of details such as joints, fixings and weld points is more important than the type of fence. It is precisely these joints that are critical to safety: weld points and the way the fence elements are fixed to the posts play a decisive role in determining the system’s resilience.
“Substandard or poorly executed welded joints can quickly become a weak point when under load,” warns Heidrich. According to him, wire mesh panels welded from raw wire generally exhibit greater stability than those made from pre-galvanised wire.
High-quality clamping or cover strips, sturdy screw connections and tamper-resistant fixings provide additional security, emphasises Heidrich. “Fixing systems play a key role, particularly in high-security applications. This is because attacks are often directed not at the mesh itself, but at the connection between the mesh and the posts,” explains Heidrich.
The RAL Quality Standard provides a basis for assessing the installation of fencing systems. The RAL GZ 602 seal serves as a guide to ensure that perimeter fencing complies with the state of the art. “The quality standard describes how metal fences should be constructed in accordance with RAL’s guidelines and our quality requirements. This is a helpful point of reference for planners, as it provides them with a certain guarantee of quality,” says Grögor.
From Fence to Security Solution
For perimeter protection to be fully effective, adjacent security components must be planned at an early stage alongside the fence itself. According to Grögor and Heidrich, this includes, for example, additional measures to prevent people from crawling under or digging under fence systems. Concrete foundations or concrete slabs can be installed beneath the fence elements to prevent anyone from getting through beneath the fence line.
To prevent people from climbing over, deterrent elements can be fitted to the top of the fence, sloping inwards, outwards or in both directions. Additional security elements such as barbed wire or rolls of barrier wire (NATO wire) can be integrated into these extensions. This makes climbing over the fence significantly more difficult.
Another approach lies in the design of the fence panels themselves. “Instead of traditional double-bar panels, tighter mesh sizes can be used. If the bars are closer together, there are fewer points of contact for hands and feet. This makes climbing over the fence considerably more difficult; without aids such as a ladder, it is much harder to scale such a fence,” explains Grögor.
According to Heidrich, the removal of fence panels to allow larger equipment to be brought in can also be effectively hindered by using one-way security screws.
However, perimeter protection only achieves its full effectiveness when combined with electronic components. Fence detection systems add a crucial function to the physical barrier: Tampering or attempts to breach the fence are not only detected immediately, but also reported directly to the operator. This allows countermeasures to be initiated without delay. “Such systems will be integrated even more closely into fence construction in future – for example through partnerships – because security requirements are continuing to rise,” says Grögor.
Comprehensive system with a plan
Although many of these security measures can be retrofitted, effective perimeter security should ideally be taken into account right from the early planning stage. This is because the fence must not be viewed in isolation. Grögor recommends planning perimeter security consistently as a comprehensive system: “Weak points often arise at the junctions. Even the best fence is useless if there is a barrier next to it that can be easily breached.”
It is important here to coordinate all components and trades at an early stage. Perimeter security is not something that is only established at the end of a construction project when the fence is erected. If detection technology needs to be integrated, cables laid or interfaces to gates, barriers and access systems created, this has a direct impact on planning, civil engineering and installation processes. Perimeter security should therefore be part of the overall planning from the outset.
Heidrich picks up on this from the perspective of a systems provider. Particularly in the case of critical infrastructure, a purely structural approach therefore falls short. “CRITIS facilities do not require a standard, off-the-shelf solution, but rather a bespoke security concept,” emphasises Heidrich. The key factors are the risks present at the specific site, which access routes need to be secured, and how early unauthorised access should be detected. Only this analysis can determine the appropriate fence height, gate and access solutions, and the detection and surveillance technology required.
In Heidrich’s view, this is also changing the way the fencing industry sees itself. The industry increasingly sees itself not merely as a provider of mechanical barriers, but as part of networked security architectures. “We expect the fencing industry to continue to evolve. The systems are becoming more diverse and complex. In particular, the integration of mechanical systems with electronic detection systems, as well as the networking of access and entry systems, will transform the scope of a fencer’s work,” says Heidrich.
