• building approximately 18 km of new 400 kV overhead line
• building approximately 11 km of new 400 kV underground cable
• removing around 27 km of existing 132 kV and 400kV overhead line between Burstall Bridge and Twinstead Tee
• additional works to support construction, including temporary construction compounds, site offices, haul roads and new road junctions (bellmouths)
• works to deliver a minimum of 10% biodiversity net gain, including planting and other environmental enhancements.

We are also building a new substation at Twinstead Green (between Butler's Wood and Walegrave Wood). The substation is where National Grid's high voltage transmission network connects into the low voltage network run by UK Power Networks, who is the distribution network operator in this area. We applied to build the GSP substation through a separate planning application to Braintree District Council, as this will reduce the overall amount of time it will take to build the project.

You can view the detailed plans included in our application for development consent by visiting the Planning Inspectorate's website here.

Current and upcoming works

Across the first half of this year, we've focused on building construction accesses and a temporary haul road so that we can reduce the need for construction traffic to use existing roads. We’ll continue to work on these over the next few months. To do this, we’ve had to carry out vegetation management (such as trimming, pruning, coppicing or removal) at various locations. The next phase of these works is planned from mid-September until the end of October. 

In the autumn, we’ll take delivery of some of the cabling that will form part of the new transmission line. We will then begin underground cable works at various locations, and construction of the new overhead line will start to ramp up.

Traffic management 

Full details of where we expect to implement traffic management measures can be found in the table below. These dates are subject to change, so we will update this page regularly as the works progress.

Public Rights of Way

Surveys

If a survey cannot take place on the scheduled date (due to factors such as poor weather conditions), we will endeavour to reschedule the survey in a timely manner.

Access to land plots is agreed before any surveys take place. If you are a landowner and have questions about surveys on your land, please get in touch via your usual point of contact or the details at the bottom of the page.

Completed works

South of Sudbury, work to build the new Twinstead Green grid supply point (GSP) substation has been progressing well. At Bramford substation, we have built the first gantries (metal structures) that will connect the new transmission line into the substation. We’ve also been working on the foundations for the first new pylons in this area and have carried out archaeological surveys at various locations.