Armored Fiber Optic Cables

Fiber optic cables are a first-rate option for transmitting data, being much faster than traditional copper Ethernet lines. Fiber cable can also run for much greater distances, giving it another leg up on copper cables. However, a potential weakness of fiber is fragility. Compared to copper cables, fiber is easier to break since it contains glass. That is where armored fiber optic cables come in.

Armored fiber optic cable can do everything standard fiber can do while also carrying additional protection. Underneath the jacket, there is a metal tube protecting the delicate fibers at the core of the cable. This metal tube does not hamper performance and provides protection from heavy objects, curious rodents, and other hazards. At the same time, the metal remains flexible enough to allow the cable to bend normally.


All the options available to normal fiber (number of fibers, PVC or plenum jackets, single-mode or multimode, etc.) are also available with armored fiber. The armor allows the cable to withstand 7x the force of conventional fiber, providing a substantially larger safety margin if a heavy object is set on the cable or falls on top of it. The protection offered by armor also increases pull tension, making fiber installations easier to manage.

The extra protection provided by armored fiber means it most commonly sees use in industrial environments. Areas with heavy equipment, moving machinery, chemical or moisture exposure, and other potential hazards have a tendency to break standard fiber fairly easily. As industries start to shift towards the faster data speeds provided by fiber, cables built for any environment will transition from convenient to necessary as fiber continues to become more widespread.


There are two main types of armored fiber: interlocking and corrugated. Interlocking armored fiber uses an aluminum sheath wrapped around the fiber strands in a helix shape. This type of armor offers the best crushing resistance and is most commonly used on indoor/outdoor fiber. Typically, interlocking armor sees use in areas where the fiber cable could find itself underneath large machinery or other sources of extreme weight.

Corrugated armor is made using coated steel tape and folded around the inner portions of the cable during fabrication. This type of armor offers the best protection against rodents that like to chew on cables. As a result, it is most commonly seen on fiber cables that will be left outdoors, in-between walls, or in other rodent-prone areas like basements.

While both interlocking and corrugated fiber have their specialties, that is simply the area of protection each type of armor excels in. Interlocking can be used in areas with rodents and corrugated can be used in areas with heavy machinery. And both types of armor are equally impressive at blocking damage from dust, moisture, oil, gas, and other hazards from outdoor and/or industrial environments. If users expect crushing weight or rodents to be a major problem, then using interlocking vs. corrugated can make a difference. Otherwise, the two are fairly similar.

Common Armored Fiber Optic Cables


Armored fiber optic cables are often installed in a network for added mechanical protection, as they have extra reinforcing in the cable housing to prevent damage. Two types of armored fiber optic cables exist: interlocking and corrugated. Interlocking armor is an aluminum armor that is helically wrapped around the cable and found in indoor and indoor/outdoor cables. It offers ruggedness and superior crush resistance. Corrugated armor is a coated steel tape folded around the cable longitudinally. It is found in outdoor cables and offers extra mechanical and rodent protection.
The Structure Of An Armored Fiber Optic Cable
In basic armored fiber cable designs, the outer sleeve provides protection against wind, solvents, and abrasion. This outer sleeve is usually made of plastic such as polyethylene. The next layer between the sleeve and the inner jacket is an armoring layer of materials that are difficult to cut, chew, or burn, such as steel tape and aluminum foil. This armoring material also prevent the fiber from being stretched during cable installation. Ripcords are usually provided directly under the armoring and the inner sleeve to aid in stripping the layer for splicing the cable to connectors or terminators. The inner jacket is a protective and flame retardant material to support the inner fiber cable bundle. The inner fiber cable bundle includes strength members, fillers and other structures to support the fibers inside. There are usually a central strength member to support the whole fiber cable.
There are several potential jacket materials are considered for armored indoor outdoor cable. The choice of jacket material depends on the required level of flame retardance in the final cable, including Polyvinyl Chloride (PVC) jacket, Halogen Free Polyolefins (HFPO) and Coated Steel Armor. Armored cable is also available with a double-armor protective jacket for added protection in harsh environments. The steel armor should always be properly grounded to an earth ground at all termination points, splice locations and all building entrances.
Benefits Of Installing Armored Cable
During some fiber optic installations, there is a need to provide extra protection for the cable due to the installation environment. That environment may be underground or in buildings with congested pathways. Installing an armored fiber-optic cable in these scenarios would provide extra protection for the optical fiber and added reliability for the network, lessening the risk of downtime and cable damage due to rodents, construction work, weight of other cables and other factors.
But one inconvenience is the need to bond and ground the cable. This inconvenience can be eliminated by using a dielectric-armored cable. Dielectric-armored cable options exist that offer the required protection without the hassle of grounding and bonding the armor, or the extra steps of installing a conduit and cable when the cable is without any armored protection.
Compared With Other Common Fiber Optic Cables
These armored fiber optic cables are the same diameter with commonly seen 2mm O.D or 3mm O.D cables, and their optical performance is also same as the common fiber optic cables. The difference is armored fiber cables are with stainless steel armor inside the cable jacket and outside the optical fiber, this stainless steel armour are strong enough to make the cables anti-rodent and the whole cable can resist the steps by an adult people.
Armored fiber optic patch cables are also can be single mode and multimode types, the connectors optional including commonly used LC, SC, ST, FC, E2000, MU, SMA, etc. Cable structure can be simplex, duplex or multi-fiber types. Armored fiber cables from can be with custom made colors and cable length, they are manufactured according to industrial and international standards.
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