Motorists have been warned to expect delays on the M6 this weekend while a huge electricity transformer is transported.

The transformer is being carried from the port at Heysham in Lancashire to a holding site at Longtown north of Carlisle in Cumbria. The operation begins at 9am from Heysham on Saturday and will last around 12 hours.

The load, more than six metres wide and weighing 450 tonnes, will travel north up the M6 from junction 34 near Lancaster, all the way through Cumbria. It will straddle two lanes of the carriageway.  It will then move into Scotland up the A74(M) where it will turn and head south – re-joining the M6 and then leaving the southbound carriageway at junction 45.

Once in Cumbria, the vehicle will park on a closed lane of the northbound exit slip road at junction 39 for a planned break before resuming its journey.  The load will exit the southbound M6 motorway at junction 45 – reversing up the entry slip road ahead of the final leg of its journey to Longtown.

The load will be moving at around 12mph along the M6 and drivers are being asked to exercise extra patience and care when overtaking in lane three of the motorway.   Drivers may be stopped temporarily at locations around junction 45 when the load is leaving the motorway.

The transformer is helping the transition to greener energy by supporting wind power generation in southern Scotland by the region's infrastructure company SP Energy Networks.

National Highways’ abnormal loads manager Gordon Beattie said: “This is an unusually wide, abnormal loads movement, but we’ve been liaising with the police as well as the authorities in Scotland to keep any disruption to other drivers’ journeys to a minimum.”

A police spokesperson said:” Using the M6 to travel through Lancashire and Cumbria this weekend? We'll be assisting in moving a large load from junction 34, near Lancaster, up through Cumbria, meaning there will be delays.”

Drivers are advised to check traffic conditions before setting out on journeys. Live traffic information is always available at www.trafficengland.com or from National Highways’ 24-7 customer contact centre at 0300 123 5000. Updates will also be posted to @HighwaysNWest – National Highways’ regional X feed.