Massive slow-moving equipment’s journey to a power station will close parts of the M25 and M1 tonight.

The M25 will be shut in both directions between junction 21a and junction 19 from 10pm until 6am tomorrow morning (March 10).

Update: the journey was cancelled at 7pm on Saturday due to "unforeseen concern regarding the transportation trailer". 

The M1 and A12 slips onto the M25 will also be closed. The M1 slip closure in both directions at junction 6a will be for the same time as the main closure while the A12 slip closure at junction 28 will be between 8pm and 5am.

Traffic is also set to be held for around 30 minutes at Gallows Corner roundabout in the A12 in Romford at around 10pm.

There are no other roads closed around the Hertfordshire M25 as part of the journey and a diversion will run through local roads.

Watford Observer: Previous abnormal road movement.Previous abnormal road movement. (Image: Mytilineos)Closures for the same stretch and during the same time frame were also in place on Saturday February 24 and will be repeated for a third and final time on March 23, subjected to conditions such as weather.

The first load, successfully transported on February 24/February 25, weighed around 350-tonnes and was more than 50-metres long.

As with tonight’s movement, it was escorted by police on a 79-mile journey from the Port of Tilbury in Essex to Millbrook Power Station in Bedfordshire.

The convoy will move at walking pace and leave Tilbury at around 4pm before arriving at around 12pm the next day. It is expected to leave the M25 at junction 21 at around 1.15am.

On completion, the in-development Millbrook Power will have the capacity to generate enough power to provide instant electricity to power 150,000 households.