National Grid is advising residents and motorists of temporary road closures and speed restrictions in the Walpole and Necton areas as a £50 million overhead power line upgrade and refurbishment project gets under way.

National Grid started work in April on the eight-month project to rewire the 52-mi (84 km) high-voltage line, running between Norwich and Walpole, near Wisbech. Engineers will renew the conductors (wires) and fittings and carry out strengthening work on some of the 224 pylons that carry the wires.

Project manager Simon Chandler said: “This work will help to ensure that our electricity supply continues to serve us safely, reliably and efficiently for decades to come, securing our energy supply for future generations.

The 400-kV power line was built in the early 1960s and now needs refurbishing. The work will enable National Grid to increase the capacity of the line and the network in East Anglia to secure future energy supplies. The project is being carried out by National Grid, leading an electricity alliance with Balfour Beatty.