Midland Main Line overhead line upgrade completed on time improving reliability and environmental efficiency

Credit: Network Rail

Network Rail has successfully completed a major £84 million project to upgrade overhead line equipment (OLE) between London St Pancras and Bedford, delivering the Midland Main Line improvement, known as OLE125, on time and under budget. The project ran from September 2023 to June 2025 and involved replacing ageing infrastructure installed in the 1980s that was no longer fit for purpose.

The upgrade enables new bi-mode trains to run at optimum speeds, improving reliability and performance while reducing diesel use, benefiting the environment. The OLE125 project, carried out with main contractor SPL Powerlines, covered 40 miles, replacing 401 head spans, upgrading 108 wire runs, and completing 209 balance weight anchor upgrades. The work involved over 636,000 hours and an average of 30 machines per shift. Routine maintenance was also undertaken to maximise track availability.

Paul Cater, Network Rail senior portfolio manager, said: “The successful OLE125 project has been about making the Midland Main Line more efficient and greener. This upgrade, combined with the wider electrification of the line, will mean the benefits are gained over a large area of our railway. We would like to thank everyone who helped us deliver the upgrades, which will have clear benefits for passengers as bi-mode trains can now run more efficiently between London and Bedford. We are also grateful to our neighbours living near the line for their patience while we worked on these major improvements, and also maximised our time on track by carrying out many other maintenance tasks at the same time.”

Steve McWhan, SPL Powerlines UK regional managing director, said: “We are extremely proud of the teamwork, commitment, collaboration and professionalism that has taken place to successfully deliver this complex and challenging project on time and to budget. OLE125 brings massive benefits to passengers with improved line speed, bringing quicker journey times. The project also brings greater reliability with life-expired equipment being replaced.”

Philippa Cresswell, customer experience director at East Midlands Railway, added: “This important infrastructure investment paves the way for our new Aurora Bi-Mode trains to operate along the Midland Main Line, enabling more reliable, environmentally friendly, and comfortable journeys in the future.”

Jenny Saunders, customer service director for Thameslink, said: “I’d like to thank passengers for their patience while these works were underway, and I hope that the benefits of these reliability improvements on our Bedford, St Albans and Luton routes is noticed.”