Normally, a fiber optic cable is made up of some fibers, with their primary coating and individual jacket in case of a tight structure fiber. This said, the cables can be built with numerous and different protections and reinforcement elements.
One of the most common needs is the protection of the cable against rodents. We can affirm that rats or mice do not literally “eat” the cables, but their teeth grow incessantly and they must gnaw continuously to wear them down and keep them in the right size. The jacket of the cables, whether fiber or copper, does not have the adequate consistency to withstand this attack.
If the rodent manages to break the cover, the safety of the fiber will be seriously compromised. What can we do to prevent this issue?
We can include anti-rodent reinforcements at different levels in the cable structure. The first one, lighter, is to add a layer of fiberglass. When gnawing the cable, the glass fibers breaks and sticks in the rodent’s mouth, it is annoying or painful for it, and it abandons its task. This is a protection we call “light”. Usually, a double jacket cable is configured in which the fiberglass is included between the two jackets. We can see it in detail in the figure:
In cases where we anticipate that these protections won’t be sufficient and, furthermore, we do not have the urgent need for the cable to be dielectric, a corrugated steel armor can be added. You can see in detail in the figure.
Corrugated steel slightly increases the diameter of the cable, the price and the difficulty of preparing the cable but its behaviour against rodents is excellent.
This type of armored cable presents a significant rigidity, which, sometimes, can be excessive. For this reason, cables have been developed whose armor is a steel spiral that provides great protection against rodents and crushing, while maintaining an excellent flexibility. We can see it in detail in these images
The spiral armor option is also available on 1 or 2 fiber drop cables.
It is always possible to increase the resistance to rodents by adding a compound to the jacket that increases the repellent effect, in addition to increasing the density of the glass fibers. This solution is especially interesting in dielectric cables since it increases their resistance without affecting their main condition.
There is a right cable for each application and environment, and it is very important to choose well the cable to be installed, so the installation process is simple and the result is optimal even in the long term.