Motorists heading back to west London from the likes of Kent, Sussex and Surrey have been warned to expect severe delays on the M25 starting tonight as a house-sized transformer begins a three-day journey around the southern stretch of the motorway.

The giant transformer, which is so big that hedges along its route have had to be trimmed before its journey, will take up to 45 hours to make it to its final destination.

Setting off at 7pm tonight (Friday, August 17), the piece of electrical equipment will travel from Essex at just 12 miles an hour and isn't expected to make it to its final destination until 4pm on Sunday.

Those using the southern stretch of the M25 while it is on the motorway will risk getting stuck behind it - as it is so big it takes up two lanes.

The transformer is being transported to West Weybridge substation, in Surrey, from Tilbury Docks, in Essex.

Letters have been sent out by National Grid to nearby residents who may be affected.

The truck which will carry the transporter is more than 68 metres long and 5.3 metres wide.

The electrical transformer set to cause hours of delays on the M25

To "keep disruption to a minimum" there will be a 24-hour stop at Clacket Lane Services to ensure the delivery can be made on Sunday when there is less traffic on the road.

The transformer will begin its journey at 7pm tonight arriving at Clacket Lane Services on the Surrey and Kent border around seven hours later, where it will then stop for more than 24 hours.

It will then resume its journey at approximately 6am on Sunday (August 19), driving along the M25 until junction 11 where it will leave the motorway and continue along the A320 towards Woking.

What's its journey?

  • It will leave Tilbury Docks via the A109 and will travel north until it meets the A13
  • It will then go along the A13 and onto the A1306
  • It will then continue up until the junction of the A282 towards the Queen Elizabeth II bridge at the Dartford Crossing
  • Once over the bridge, it will exit at junction 1A and go along the A206, B255 and A2 before rejoining the M25 at junction 2
  • The transformer will exit the M25 at junction 11 and continue on local roads until it reaches its destination

People planning to use any of the above routes in the allotted times have been urged to re-think their journeys or allow extra time.