Which benefits of rolling out flat cables in overhead lines ?

Although less used than cables with round structure, flat optical cables are just as reliable for the roll-out of aerial networks. Developed in the late 1950s to meet the requirements of aerospace applications, flat cables have since been adopted by a large number of industries due to their great flexibility. In telecommunications, depending on the application for which they are used, flat cables offer even higher performances than round cables, notably in terms of flex. Thus, flat cables are particularly appreciated for installations with small bending radii and high bending cycles.

Flat cables are also a more suitable solution for the deployment of overhead lines in case of overloaded telecom infrastructure as they alleviate spacing needs. In general, these cables take up half as much space as round cables. Thus, they are naturally lighter than optical cables with round structure and they enable to cut off by nearly half the weight supported by the poles or facades during their roll-out.

How to choose the appropriate flat cable fastening solution for the rollout of overhead networks?

Depending on the network configuration, flat cables can be installed on utility or telecommunications poles by using anchor clamps and suspension devices developed for this purpose. To make an informed choice between the different solutions, a referential of securing overhead lines is free for consultation.

For the flat cables dead-ending, there are various technological solutions including conical clamping and wedge clamp devices. Before selecting a solution for  anchoring flat cables compatible with your overhead installation, a particular attention should be paid to the following installation conditions:

drop clamp for flat aerial cables

  • the span length
  • the tensile strength
  • climatic data
  • the degree of congestion at the anchoring point

However, there are situations when several clamp models are compatible with one type of cable. For instance, the dead-ending of flat cables rolled out on distribution or access networks with spans up to 70 meters can be performed by using a Hypoclamp F, an ODWAC or a 5/35 FTTH F drop clamps. The choice between these three solutions shall first be made by ensuring the match between the cable’s dimensions and the permissible range of the selected clamp. Then, the focus will be on the provided mechanical and environmental performances. Thus, for the anchoring of flat drop cables with dimensions up to 7x3mm, the 5/35 FTTH F drop clamps are most suitable devices.

For the termination of flat cables with larger dimensions on poles or facades it is preferable to use Hypoclamp F or ODWAC. The difference between these two clamps consists in their design. Although both are based on conical clamping technology, these solutions are built differently and made of distinct materials. ODWAC anchor clamps present an elongated bail and are fully made of stainless steel, while Hypoclamp F clamps present a plastic wedge and an opening and lockable bail at its extremity.

For the dead-ending of flat drop cables rolled out on spans up to 90 meters, the ODWAC XL anchor clamps are most appropriate solutions. Indeed, these drop devices for flat cables offer a 150daN tensile strength against only 100daN for the ODWAC version. Also, to guarantee superior mechanical performances, these clamps are developed with longer body and bail lengths than ODWAC clamps.

Which suspension solutions for flat cables ?

To ensure reliable and future-proof telecom networks, it is important to select a network equipment that meets the needs of your installation. You will find here below the main elements to examine in order to make certain that the deployed flat cables are compatible with the suspension devices used for the roll-out on intermediate poles:

  • the network type on which the flat cable is deployed (utility or telecommunications networks)
  • the cable span
  • the cable’s dimensions

Thus, for performing suspension applications on MV networks where spans do not exceed 180 meters, it is advisible to use suspension devices for long spans such as those included in the DSAL range and covering a wide range of flat cable sizes.

For the suspension of fiber optic flat cables rolled out on telecommunications networks with spans up to 70 meters, DS suspension devices are the solutions to retain. Consisting of a hinged plastic shell equipped with an elastomer insert and an opening bail, DS suspension devices are lightweight and compatible with small cable dimensions, from 2 to 8mm. Designed as mobile suspension solutions, DS devices enable to protect cables against aeolian vibrations.