Network Rail has completed the UK’s first low-carbon track renewal, replacing 1,150 yards of plain line track between Honor Oak Park and Forest Hill using a suite of sustainable materials – a milestone that supports its commitment to net zero by 2050.
Led by the Southern Renewals Enterprise, the project combined green steel rail, low-carbon concrete sleepers, recycled ballast, and renewable biofuel-powered trains to cut emissions without compromising performance. The track was fully welded, stressed, and handed back early at line speed, proving that sustainability and operational excellence can go hand in hand.
Key innovations included:
- Green steel rail produced via electric arc furnace, reducing carbon intensity by around 60%.
- Low-carbon concrete sleepers, cutting embodied carbon by 40%.
- Recycled blended ballast, saving up to 13% carbon by reducing virgin aggregate use.
- ISCC-certified renewable biofuel (HVO) for trains.
- Solar-powered welfare units, eliminating diesel generators on-site.
The combined approach achieved a 63% reduction in emissions compared to traditional methods – equivalent to the annual emissions of 200 UK households. Across the first year of the programme, SRE delivered a 10.2% whole-life carbon reduction, setting a benchmark for future renewals.
Dave Sutton, Project Lead for SRE Track, 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.”
SID Director at Network Rail, Liz Baldwin, added:
“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.”
This project demonstrates how collaboration between Network Rail Supply Chain Operations, the Environment & Sustainability team, and industry partners can embed sustainability into everyday delivery. Green steel and low-carbon sleepers are now being scaled across SRE projects, with plans to expand blended ballast nationally.
While challenges remain in scaling supply chains and managing costs, the Honor Oak Park renewal provides a replicable model for a greener, future-proofed railway, aligning with the UK’s 2050 net zero target.
Image credit: Network Rail
