In the article "Β» I wrote about the problems of existing classical systems, and how developers are now solving them.
Several paragraphs of the publication were devoted to fences. I decided to develop this topic and introduce Habr's readers to RPZ - radio-transparent barriers.
I do not pretend to the depth of the material, rather, I propose to discuss in the comments the features of using this technology for modern perimeter security.
The problem of classical engineering barriers
The sensitive facilities that I managed to visit are often fenced with reinforced concrete structures or metal mesh fences.
Their main problem is that a large number of radio wave devices are almost always located in a protected area, the stable operation of which is hindered by classic engineering barriers.
In particular, this is critical for airports, where it is necessary to eliminate radio interference as much as possible.
Is there an alternative?
Yes. Structures made of modern composite materials, which began to be used several years ago for the construction of engineering fences.
They not only do not interfere with the passage of electromagnetic waves, but are light and durable.
In the photo below, a radio-transparent barrier based on a fabric made of reinforced fiberglass mesh with a cell size of 200x50 mm (section length 50 meters, width 2,5 m), which is produced in Russia. The maximum breaking load at break is 1200 kg, at break 1500 kg. The weight of the section is only 60 kg.
The structure is mounted on fiberglass supports and assembled by a team of 5-6 people.
In fact, the whole "set" of components is very similar to the designer, which includes wickets, gates and everything else. You can assemble a strong fence up to 6 meters high. Sliding gates are mounted within an hour.
An example of a "two-story fence"
Sliding gates
Additionally, to protect against undermining, the fence is deepened to 50 cm.
additional benefits
- When colliding with an obstacle at speed, the grid is fragmentarily destroyed, and the damage to equipment (for example, an aircraft) is minimal;
- On the RPZ, as well as on concrete fences, devices for protecting the perimeter and a radio-transparent barbed spiral are mounted;
- Can be used as an alarm barrier (vibration sensors);
- No complicated landscaping required;
- Fences do not rust and do not require seasonal maintenance.
The design described in this material uses brackets, self-tapping screws and stainless steel lining. Despite this, the radio transparency parameters practically do not deteriorate: the elements are small and located at a sufficiently large distance from each other. Therefore, the mount does not significantly reflect incident radio waves (in a wide frequency range, up to 25 GHz).
Metal fencing elements
The developer plans to replace most of the metal elements with various types of high-strength plastic after the upgrade.
Video editing
Additional photos
I invite you to discuss the features of such solutions in the comments. Ready to answer questions.
Source: habr.com