As South Africa’s consumers today demand faster and more reliable connectivity for a range of home and home-office uses, Raubex Infra is working with telecommunications operators to roll out the ‘last-mile’ optical fibre cabling to the household.

In a recent contract, Raubex Infra’s telecommunications division – which provides a diversity of network infrastructure solutions – provided fibre links to 2,200 homes in the Universitas and Waverley neighbourhoods of Bloemfontein in the Free State province.

According to Danie Marias, operations director of the company’s telecommunications division, the project required the deployment of specialised equipment as well as the careful management of teams of trained workers for the manual aspects of the job. He highlights the importance of working neatly, quietly and quickly in the suburban environment, creating as little disruption as possible to the residents.

The well-coordinated effort using a specialised trenching machine created a narrow slot some 20 to 30 cm deep in the roadway, into which the ducting was laid from a large reel. While this task could be best conducted using mechanised means, the shallow gulley for ducting to run from the road to the householder’s fence had to be manually dug. A termination box was then located at the edge of each property for later connection to network.

Marais emphasises the importance of restoring the roadway to its previous condition of strength to avoid any ingress of water through weak points in the asphalt as this could reduce the lifespan of the road. The gravel removed by the trencher is therefore meticulously swept up and transported to a nearby site, where it is sieved and mixed with cement by a dedicated mixer to create a soilcrete mixture.

Once moistened, the soilcrete can be packed into the roadway slot on top of the ducting, and then compacted to the required density ensuring the road layers are returned to their previous strength. The filled slot is then sealed with bitumen paint before a final asphalt layer is applied and compacted with a pedestrian plate compactor.

In addition to conventional trenching operations, this division of Raubex Infra also conducts large-scale trenchless ‘direct lay’ projects over hundreds of kilometres, installing ducting for national fibre backbones using specialised heavy machinery. It also has extensive experience in horizontal drilling for the installation of underground cables, conduits and pipes.