Concertina Barrier Diameter
The diameter of the concertina security barrier – would it seem simple? It turns out that it’s not at all simple. Many customers have questions like “we ordered the “Egoza-Cayman-600/5” concertina security barrier, but after measuring its height on the fence, we found that its height is approximately 500 mm. And it should be 600 mm. Have we been deceived?” No, these are just the laws of physics.
It is quite difficult to correctly measure or calculate the diameter of a concertina barbed wire barrier. First you need to realize that there are several diameters of the same spiral fence, and all of them differ depending on the design of the concertina barbed wire barrier, the features of its installation and the correctness of the measurements.
For clarity, we consider the diameters of a barbed wire concertina barrier at all stages of its existence – from manufacturing to operation at the facility, as well as the design features of the concertina security barrier from modern barbed wire that affect the accuracy of measuring its diameter. For clarity, text is illustrated with photographs of a concertina barrier at various stages and with drawings for measuring the diameter of the concertina.
Estimated diameter of the concertina barrier
We offer a table with the calculated diameters of the concertina security barrier installed with stretching to the recommended length.
|Coil diameter, mm||Installed barrier diameter, mm|
The diameter of the concertina barrier in its production
The manufacturing technology of concertina security barrier provides for the winding of razor wire on a drum of a certain diameter and the fastening of adjacent turns of the fence with special clips. The diameter of the drum is selected in such a way as to form coils of a given diameter, taking into account the diameter of the barbed wire itself. This is the diameter of the concertina barrier, which is indicated in the price list and other documentation. And this is the only diameter of the concertina security barrier that can be controlled.
The diameter of the concertina barrier in the transport position
After removal from the drum, the concertina security barrier is compressed into more compact bays for convenient transportation and storage, in which the turns of the spiral fence are slightly displaced from each other and slightly deformed. It is possible to measure the diameter of a concertina razor wire barrier in a warehouse, but already with an error of 20-30 mm for small diameters. Barriers with a diameter of 1000 mm or more in the transport position can be elliptical, which further complicates the process of measuring their diameter.
The diameter of the concertina barrier installed on the object
When installing a concertina razor wire barrier, it stretches to a certain length, while its diameter decreases in proportion to the stretch. For this reason, we always indicate the recommended and maximum tensile lengths for each type of concertina barbed wire barrier. The maximum efficiency of the spiral boom will be at the minimum stretching indicated in the price list and the characteristics of the barrier, acceptable – if you do not exceed the maximum allowable amount of stretching.
With proper installation and stretching to the recommended size, the diameter of the concertina barrier is reduced by 10-12% relative to the diameter of the concertina security barrier manufactured in the production. Accordingly, the diameter of the fence “Egoza-Cayman-600/5” after its professional installation should be 530-540 mm. But customers measured their barrage and got about 500 mm. What is the matter?
The diameter of the concertina security barrier and the features of its measurement at the facility
The diameter of the fence has become even smaller? Everything is very simple, although not everyone understands it at first glance. But the point here is the technology for the production of concertina security barriers, part of which was described at the beginning of the article – the barbed wire is wound around the drum and the adjacent concertina turns are stapled in a checkerboard pattern, forming diamond-shaped cells. An odd number of clips is necessarily used to fasten the coils of the concertina barrier so that all coils of the concertina can be fastened.
During installation, the concertina security barrier is stretched, taking, as they say, the shape of a cylinder. But in reality, this is not a cylinder, three-five-seven-more-faceted (depending on the number of clips on a pair of coil turns), in front of which the clip is installed, there is not another clip or razor wire, but the middle of the cell from barbed wire, etc. e. air. The fact that a concertina barbed wire barrier has a cross section not of a circle, but of a polyhedron interferes with the measurement of its diameter, since it is usually not the actual diameter of the concertina security barrier that is measured, but the size of the polyhedron inscribed in this diameter – this size will be even smaller than the calculated diameter of the barrier. Yes, and measuring the diameter of the concertina from the clip to the air on the opposite side of the spiral does not increase the accuracy of measuring.
How to measure the diameter of a concertina security barrier?
There is a difficult way to find out the exact diameter of the fence in the initial and mounted position. To do this, cut and remove a couple of turns of a concertina security barrier, put it on a flat surface, and, giving the shape of an ideal circle, measure the diameter of the barrier. The diameter of the concertina barbed wire fence installed at the facility can also be measured if you try hard. To do this, it is necessary to wrap the concertina with a dense flexible material such as flexible plastic or thick cardboard, so that it forms a ring adjacent to the concertina barrier from the outside. In this case, the ring should have the shape of a circle, not a polyhedron, and have a width of not less than the distance between the fastening points of the concertina coils so that the ring rests on them. And the inner diameter of this ring will be the diameter of the installed concertina barbed wire barrier.
If you are not a fan of overcoming unnecessary difficulties, there is a very simple way to find out the diameter of the concertina security barrier – you can just look in the accompanying documentation or read the information indicated on our website for a specific type of product. And also to accept the fact that during installation the diameter of the concertina barbed wire barrier in any case will decrease.
❓ How does the diameter of the concertina barrier change during installation?
✅ The diameter of the concertina barrier on the fence is reduced relative to the diameter of the coil by 10-12%.
❓ Can the diameter of the spiral fence be accurately measured?
✅ No, there will always be an error.