Fibre optic cables for the introduction of modern internet systems are typically installed in two ways, either underground in a conduit or via aerial cable on fibre poles. Often both methods are used in the same country for various reasons.

While underground cabling is the preferred method of choice by many global municipalities due to its aesthetic appeal, there are three main factors that influence why fibre is often installed aboveground. We have a look at those three factors in this blog:

1. SPEED

The landscape plays a key role in determining whether fibre should be installed underground or overground using fibre poles. Underground digging in uneven or rocky ground is often very time consuming and costly while steep bends or hills can be impossible to navigate via a subterranean installation method. Thus, above ground pole-based solutions are the best choice in this type of environment.

When opting for an aerial fibre installation this is done in a very similar method to the old-style telephone poles that can still be seen around much of South Africa. In fact, as fibre cables are relatively lightweight, they can even be installed on existing wooden telephone poles, thus dramatically decreasing the time taken for installation. As most rural or older houses already have some services installed by means of utility poles, attaching fibre to these existing wooden poles allows providers to cover more ground and provide internet to outlying rural communities and isolated homes quickly.

2. COST

When going underground with fibre cables, existing municipal services can be disrupted or broken which can come at great expense, especially if existing services need to be redirected. In addition, having to dig through concrete or tar roads and sidewalks is disruptive to residents and commuters and occurs additional costs.

That is why it makes sense that municipalities often opt instead to make use of their existing poles and infrastructure. As fibre cables can run alongside traditional telephone or power lines, utility poles can be shared which of course reduces costs. As a result, aerial fibre installation is cheaper to install than buried fibre networks.

3. SECURITY

While aerial fibre installations are exposed to the elements and can be susceptible to high winds, damage from birds or squirrels, cable sags or freezing, they are not affected by flood damage like underground installations. Also, cable that has been installed too close to the surface can be vulnerable and a more expensive cable may have to be used to protect it from earth movement. If an underground fibre cable gets broken it can be very costly to determine where the break is and do the repair, which is not the case when cables are installed aboveground on fibre poles.

In addition, cable that is installed on wooden poles cannot be dug up and stolen or vandalised, while cable that is close to electricity services has an added layer of protection due to the deterrent of power conductors.