With the electricity transmission network operating at up to 400kV, it’s a matter of life and death that people working nearby are kept safe.
Overhead lines and cables manager Damien Culley and his team work tirelessly to ensure landowners, developers and third parties around the UK work safely and responsibly.
Because when you own and operate 15,000km of overhead power lines and 1,000km of underground cables it’s inevitable that landowners, developers and third parties such as contractors will want to work nearby.
“We receive hundreds of enquiries a month,” said Damien. “It’s not our business to constrain landowners from carrying out development, but it is our business to keep people safe and make sure work is carried out without disrupting the secure and reliable operation of our network. Our priorities are straightforward and we have well-established processes in place to manage enquiries and make sure we find mutually acceptable solutions.”
There is definitely room for improvement. People still go ahead with developments without contacting National Grid and there have been life-threatening near misses where workers haven’t been aware that cables are buried beneath them.
Damien said: “That’s why it’s important we take a responsible and proactive approach to raising awareness of the risks involved – and the steps that landowners and developers need to take to safely carry out this kind of work.”
Anybody planning work close to National Grid infrastructure should contact us as soon as possible by phone, email or letter – or by completing their details on a simple automated system. From there, we’ll risk assess your proposals, provide the relevant drawings to locate where our equipment is, and inform you of all the possible risks and hazards involved that you’ll need to build into your plans.
Some of these, particularly if you’re new to development, are surprising. Not least the way we measure safety clearances, which are an important consideration for anyone working beneath our power lines.
At the voltages National Grid operate at, it’s possible for electricity to jump several metres from a conductor and kill or cause serious injury to anyone too close by. So it’s essential that a safe distance is kept between conductors, people and objects.
“What we’ve seen on several occasions is developers underestimating the correct safety clearance,” said Dean. “They arrive on site and see our cables sitting high and assume there’s plenty of room for them to work and build. But we’re legally obliged to assess the clearance distance at the biggest possible sag, which means the lowest possible point it could be from the ground under the biggest power flow on the hottest day.
“There have been instances where landowners or developers and their contractors have proceeded a long way into projects, assuming far greater clearances than they’re actually allowed. This not only makes for a very awkward conversation between us and them, but also introduces extra costs and delays in making design changes further down the line.”
Other issues to be aware of
- Providing access to National Grid – we have existing land rights in place near our assets that allow us to access them for maintenance, repair and renewal so it’s important your designs include a clear corridor for us to work in.
- Microshocks – large electrical conductors create an electrical field, so anything metallic near to them (within tens of metres) has the potential to pick up a charge. This can cause small shocks to anyone who touches a charged item. Not harmful but unpleasant.
- Induced charges – electrical equipment installed near our equipment can be damaged by induced current, where electrical current flows through it.
- Fires and firefighting – the fire service may not tackle a fire near an overhead line until National Grid’s engineers have made it safe and that could delay firefighting for hours, by which time a building could have burned to the ground. Factor this into your emergency plans and insurance arrangements.
“We saw someone strike our underground cables with an excavator because they hadn’t checked on the location of our assets”
Not informing us about work close to our equipment can result in a serious breach of safety. While it’s easy to see if a pylon is close by, that’s not the case with high-voltage underground cables which could be less than a metre under your feet in the middle of a green park – or at the end of a garden. So it pays to check with us.
“We recently saw someone strike our underground cables with an excavator, because they hadn’t checked on the location of our assets,” said Damien. “They’d cut through the cable’s cooling pipes and missed the high voltage line by a couple of centimetres. If they had done so, it’s likely they’d have been killed.”
“We need to know what work is happening and where in order to stay in control of our operations. For example, if a developer restricted our access and there was an emergency, we’d have to find a way to get to our towers. If the only way of doing that was by coming in through people’s gardens with HGVs, then we’d have no choice but to do so.”
“If down the line, we discover someone has built something that is too close to our equipment, we have to do remedial work to fix it,” said Damien. “This ends up costing the UK consumer – and in some cases the third party – a lot of money. But these are worst-case scenarios. And there’s no reason for them to play out.”
“We can help you to factor all kinds of hazards into your designs, which will save you time and money”
As soon as you have an idea of what you’re intending to do, use our third-party processes to tell us what you’re doing and where you’re working. If it looks simple, we’ll be able to give you the location of any risks and provide you with the green light to move forward. If it’s more complex, we may arrange a site visit to talk in more depth about the issues you need to be aware of.
“With advance warning, we can help you to factor all kinds of hazards into your designs, which will save you time and money in the long run,” said Damien. “We’re not here to stop people doing what they want, but we are here to ensure landowners, developers and third parties work safely.
To contact us directly
To report damage to electricity cables or overhead lines: call 0800 40 40 90 at any time, day or night.