National Grid will deliver a new supergrid transformer to its West Weybridge substation in New Haw near Addlestone, helping to modernise substation equipment by replacing an asset that has reached the end of its working life.

The transformer, weighing 155-tonnes – the equivalent of 25 African elephants – will make its way from the Port of Tilbury on the evening of Saturday 16 November and arrive at the substation in the early hours of Sunday 17 November.

Transformers play a vital role in helping to ensure the UK continues to enjoy safe and reliable energy supplies, stepping voltage up or down so electricity can be efficiently transmitted from power generators or safely distributed to homes and businesses via regional networks.

The transformer will be delivered on a large specialist vehicle travelling at a maximum speed of 12 mph with a police escort. The convoy travels from Tilbury via the M25, leaving at junction 11 around midnight. It is expected to arrive at the substation around 3am.

Leaving the Wisley Interchange, it heads west on the A320 St Peter’s Way, turns left at Ottershaw roundabout onto the A320 continuing into Chertsey Road A320. At Six Crossroads Roundabout it turns left onto A425 Woodham Lane, continuing on B385 Woodham Lane under the M25.

At New Haw Lock the convoy turns right onto the A318 Byfleet Road.

The route has been carefully planned in collaboration with highway authorities and the police to minimise disruption. The vehicle will have a police escort to help manage traffic and some street furniture will be temporarily removed so the transporter convoy can make its way to the substation.

Traffic travelling at this time may be held briefly to allow the convoy to pass.