Frequently asked questions
National Grid owns and operates the electricity transmission network in England and Wales.
We will be carrying out essential maintenance work to the 400kV overhead line between Mannington in Dorset and Nursling in Southampton. The overhead line in this section is approximately 40km/ 25 miles in length with 115 steel towers (pylons), although not all of these will require refurbishment works.
Before the main refurbishment work begins, an inspection of pylons is required to assess their condition. This requires the site surrounding each pylon to be prepared to ensure our contractors can access the pylons safely, which involves clearing any vegetation and undertaking minor civil works to create safe access routes.
To see where works will be taking place, please view our interactive map here.
Whilst the refurbishments are taking place, you can expect to see works to establish access routes to pylons and engineers working at height to refurbish the circuits, which will include replacing the conductors and insulators on individual pylons.
Our working hours will be 7am to 5pm Monday to Sunday across the Winter period and 7am to 6pm across the Summer period.
Works will be carried out in phases, so those living near the line should not expect to see staff working in one area during the entire working period.
None of the works will affect electricity supplies.
The overhead line consists of 115 pylons, each containing two circuits. Works to each circuit will be undertaken separately so that electricity transmission can be maintained when one side of the pylons is switched off.
Our main refurbishment work is expected to begin in June 2026 and is anticipated to last until November 2026.
A full, expected timetable is below:
- January 2026 to May 2026 – Initial site set up, including vegetation clearance and pylon inspections
- June 2026 to July 2026 – First round of refurbishment works to circuits on one side of the pylons
- Summer 2026 – Second round of vegetation clearance to remove any regrowth so that works can continue safely on the remaining circuits
- July 2026 to September 2026 – Second round of refurbishment works to circuits on one side of the pylons
- September 2026 to November 2026 – Demobilisation, reinstatement and expected completion
We take safety very seriously and will discuss any work that takes place directly over people’s properties with the landowner in advance and ensure that where needed the relevant protection is put in place.
We do not expect any major disruption in the areas where works are taking place, but you may hear some noise during the works or observe some construction traffic.
No, these works will not involve constructing any new pylons. Instead, we will be refurbishing the pylons on the existing route between the Mannington and Nursling substations.
To carry out these works we will need to temporarily close a small number of local roads, footpaths and bridleways in certain areas where they intersect with the overhead line route. These closures will ensure the safety of members of the public and workers whilst these essential maintenance works take place.
The closures will be kept to a minimum and subject to approvals through agreement with the relevant local authority. We will ensure that all closures are clearly communicated with local communities well in advance of them taking place.
Road and lane closures will be kept to a minimum and only implemented following agreement with the relevant local authority. You may notice some temporary traffic management signage for site access and diversions, for example where we install scaffolding and netting in specific locations to enable works on pylons. These measures are crucial to ensure the safety of both members of the public and our team whilst these essential works take place.
The amount of traffic going to and from pylons will depend on when the work is due to be carried out. There may be a small increase in construction vehicles using some local roads during certain stages the project. Where this is the case, we will manage the volume of movements to limit any disruption as far as possible.
We need to clear vegetation from around the base of some of the pylons and underneath overhead lines so that our contractors can have the access they need to be able to carry out the refurbishment work safely.
We are committed to minimising the impact of our work on local wildlife and the environment. We will work under the guidance of our ecologists when we remove the vegetation to ensure that what we clear is proportionate.
All vegetation clearance is being undertaken in line with the guidance and consent provided by the relevant authorities. We will work in agreement with the relevant landowners to ensure any reinstatement required after the work is appropriate to the level of impact.
We are committed to minimising the impact of our work on local wildlife and the environment across all projects.
Our ecologists have undertaken extensive survey work along the overhead line route, including site walkovers and targeted species surveys at specific locations. We will work under the guidance of ecologists when we remove the vegetation to ensure the clearance is kept to a minimum.
These refurbishment works form part of our management of the high-voltage electricity transmission network. Refurbishment forms part of our annual multibillion pound investment and management in maintaining and upgrading infrastructure to ensure a resilient and reliable network for homes and businesses in the UK for years to come.
Should you have any questions, feedback or concerns, please contact our Community Relations team via:
- Phone: 0800 099 6087 (available on weekdays between 9am and 5pm)
- Email: [email protected]