Backbone closures


Big, bigger, best

Backbone closures are the biggest in their category and allow for the processing of hundreds of fibers. The Backbone closure is mainly applied in highly sensitive optical fiber networks over long distances, for example between two city rings. In these closures two or more optical fiber cables can be spliced together in a simple way, for example with a fiber management system. Infraconcepts supplies, among other things, the backbone closures FIST-GCO2, FLAT, and KM2 direct buried closure.


The FIST-GCO2 is available in the round GCO2 and the FLAT version. In the biggest model of the GCO2 as many as 672 fibers can be spliced off. In the FLAT-closure, the maximum number of spliced fibers is 144, and for the KM2 a number of 288 fibers to be spliced applies.
The closures have an IP-value of 68, meaning 100% water-tight down to 5 meters under water. Backbone closures are often placed in handholes, with the exception of the KM2.

The FIST-GCO2 is the most standard version you run into in networks in which all types of cables are installed, such as loose tubes, uni-tubes, and ribbon cables. Cables can be introduced through oval ports (for a window-cut, for example), or round ports (for example when splicing , or branching off from the backbone cable). Watertight closing is done with shrinking seals or gel-seals. This method for finishing also applies to the FLAT-closure.
The KM2-closure can be placed in the ground directly. Right onto the closure the cable-protection tubes can be mounted. The optical fiber cables are blown in those tubes, after which the optical fibers are spliced on the SK121 splicing boxes. It’s also possible to install direct buried cables (groundcables) directly on the KM2.

You decide

  • Standard or compact (round or flat model).
  • Placement in handhole or directly in the ground.
  • Gel-seals or shrinking seals are used.
  • Underground or above ground (mounted on brackets).
  • Type optical fiber cable, number of fibers to be installed (as many as 672 fibers in 1 closure).
  • Splice-splice, window-cut, or both.

Your advantages

  • Easy: Simple to install thanks to years of improvements and innovations of the most-used closure world-wide.
  • Multi-functional: Can be used for all types of cables.
  • Accessible: Access from below (GCO2), or divisible scale (KM2).

More information

For more information or advice on the Backbone closures from Infraconcepts you are welcome to contact one of our advisors at all times.



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