Network Rail has completed the UK’s first low-carbon track renewal between Honor Oak Park and Forest Hill in south London, using a combination of sustainable materials and renewable energy to significantly cut emissions without compromising performance.
Led by the Southern Renewals Enterprise (SRE) – Network Rail’s integrated delivery team in the south of England – and its Track business partner VolkerRail, the project renewed 1,150 yards of plain line track using green steel rail, low-carbon concrete sleepers, recycled ballast and biofueled trains. The work was fully welded, stressed and handed back early at line speed, demonstrating how sustainability and operational efficiency can be achieved together.
Materials such as steel, concrete and ballast account for around 90% of the carbon footprint in traditional track renewals. To address this, the project introduced several first-in-rail innovations, including green steel produced via electric arc furnace technology (cutting carbon intensity by around 60%), low-carbon concrete sleepers with 40% less embodied carbon, and recycled blended ballast reducing emissions by up to 13%. The project also used ISCC-certified renewable biofuel and solar-powered welfare units to minimise on-site emissions.
The results were significant, with a 63% reduction in carbon emissions – equivalent to 581 tonnes of CO2e or the annual emissions of approximately 200 UK households. Across the first year of the programme, from April 2024 to April 2025, the SRE achieved a 10.2% reduction in whole-life carbon compared with baseline methods.
The success of the Honor Oak Park project highlights the impact of collaboration between SRE Track, Network Rail Supply Chain Operations, the Environment & Sustainability team, and partners across the wider supply chain. Green steel, low-carbon sleepers and blended ballast are now being adopted across SRE projects, marking a major step towards scaling low-carbon materials nationwide.
Dave Sutton, SRE Track Project Lead, said:
“This project shows what’s possible when innovation and teamwork come together. It’s the first of many greener renewals we plan to deliver – helping us move steadily toward Network Rail’s net zero goals.”
Liz Baldwin, SID Director, said:
“Congratulations to everyone who contributed to delivering this significant achievement. It is a proud moment for our team and a powerful signal of what’s to come. The success of this project demonstrates that sustainable rail delivery is not only possible – it’s scalable.”
The initiative contributes directly to Network Rail’s commitment to align with the UK’s 2050 net zero target, offering a practical model for embedding sustainability into everyday rail delivery and advancing the transition to a greener, more resilient railway.
