Drivers warned of abnormal load on M25

The convoy is expected to arrive at the substation early on Sunday morning

A transformer weighing "the equivalent of 25 African elephants" will be driven through Surrey this weekend, the National Grid has announced.

The 155-tonne supergrid transformer is part of improvement works at the West Weybridge substation in New Haw near Addlestone.

Under police escort, a convoy travelling under 12mph (19km/h) will make its way from Tilbury along the M25 on Saturday evening and is expected to arrive at the substation in the early hours of Sunday.

Motorists were advised the route has been "carefully planned in collaboration with highway authorities and the police to minimise disruption".

Traffic could be held briefly to allow the convoy to pass, said National Grid in a statement.

Project manager Mark Ellis said: "The movement is occurring at this time to try and minimise disruption to the local road network. Noise will be kept to a minimum.

"We appreciate the cooperation and understanding of the local community during this vital work maintaining the resilience of our energy network.”