Motorists have been warned to expect disruption on some of Wiltshire’s busiest roads while National Grid transports a huge piece of equipment.

A shunt reactor will be moved from the Avonmouth Docks in Bristol to Melksham Substation on Wednesday, December 6.

The 131-tonne piece of equipment is over seven metres long and almost four metres high, meaning its transportation will require rolling lane and road closures to ensure traffic is managed safely.

Its journey is expected to begin at 9.30am and will take it through Wiltshire on a number of key roads, including the M4, the A350 at Chippenham, the A4 Bath Road, and the A365.

Drivers using these roads have been warned to allow additional journey time or use alternative routes.

The shunt reactor is expected to reach Melksham at 2pm, but this will be dependent on traffic and weather conditions.

Wiltshire Times: The shunt reactor's route through WiltshireThe shunt reactor's route through Wiltshire (Image: National Grid)

Locals can stay updated on its movements via a broadcast text service that can be subscribed to by texting A2M to 82228.

The piece of equipment is required to continue reliably and efficiently providing power from the Melksham substation, a key part of the local infrastructure.

National Grid and its delivery partner Allelys have been working in liaison with National Highways and police for months to plan the critical piece of kit’s route.

David Shaw, a project manager for National Grid, said: “Local people rely on us to supply their electricity without interruption so it’s important that we keep our substations and the equipment in them working effectively.

“The delivery and installation of a new shunt reactor at Melksham will ensure we can continue to deliver power reliably and safely to the local area.

“We are working closely with the local councils and Highways England to ensure the safe and smooth load movement and we know local people may be interested to view the display of logistics and engineering.”

The shunt reactor’s full route from Bristol to Melksham can be found below.

  • Exit Avonmouth Docks via Kind Road Avenue
  • Merge onto A4 Crowley Way
  • Merge onto M5 northbound
  • Exit M5 junction 16 and take slip road to M4 eastbound
  • Exit M4 junction 17
  • Turn right onto A350
  • Turn right onto A4 Bath Road
  • Turn left onto B3109 Bradford Road
  • Turn left onto A365
  • Turn left onto B3353 Corsham Road
  • Turn right onto Westlands Lane
  • Turn right into National Grid Melksham