Cables aren’t discussed that often in the British media, particularly when it comes to the kind of technical specifics we get into on this blog. For most people, the only thing that matters is that the cable works! However, there are two common topics that frequently come up when cables are discussed. The first is the cost of cables in relation to their quality; this usually relates to home theatre set-ups. The second is the effect cables and pylons have on the beauty of the British countryside. Pylons are generally considered a necessary evil. They provide us with constant power for our homes and the trade-off is a couple of pylons dotted around the local area. Over time, these pylons gradually become part of the scenery and are practically ignored. The issue becomes more pertinent in areas of natural beauty, such as national parks and the rare untouched patch of countryside. Pylons in these areas stick out like a sore thumb and many consider them to be detrimental to Britain’s natural beauty. There has been a relatively high profile case of this in the past month or so. There are currently plans to erect new pylons through the Lake District National Park in order to carry electricity from Sellafield power plant to the National Grid. Naturally, this has been met with much opposition and alternative solutions are now being proposed, including the environmentalist’s choice of power transmission: underground cables.

Underground cables vs. pylons

The arguments for underground cables in an area such as the Lake District National Park are compelling and would seem to offer the perfect compromise between transmitting power and retaining the natural beauty of the area. Underground cables essentially do the same job as pylons, with one fundamental difference; the cables are placed underground rather than above it. As a result, most people won’t even know the cables are there. In terms of performance, there is relatively little difference between the two methods. Unfortunately, the sheer amount of labour and the cost of the custom designed cables required for underground power mean that the price far outweighs that of erecting pylons. A study commissioned by the government suggests that underground cables cost ten times as much to install, a cost difference of between £10-24 million. Part of the reason for this huge cost difference is the labour required to lay the cables; the area needs to be excavated and cleared of any obstructions before an intensive laying process. Once covered again, maintenance of the cables becomes another issue. While a lot of construction firms will create dedicated points where over ground maintenance can be carried out, some errors will require the ground to be dug up again. Being situated underground doesn’t mean that the cables are entirely safe from damage either. A badly-planned construction project can lead to cables being severed by careless workers, cutting off power to thousands of homes and requiring a large maintenance job to repair.

The construction of underground cables

Underground cables operate in unique conditions, meaning that extra care has to be paid to the cable construction. Most underground cables will be multicore cables. The obvious danger to underground cables is the effects of ground water. To reduce these effects, a cable should be waterproof, utilising water proof conductors and cable jacketing. The cable jacket doesn’t just need to be waterproof either; it also needs to be damage proof. A sturdy cable jacket made from highly resistant materials should do the trick, although metal is occasionally used to further protect the cable from damage. For more information on underground cables and their uses, get in touch with the team at Custom Designed Cables.