South Rail Systems Alliance completes historic track renewal in Severn Tunnel
Posted: 26 July 2024 | Global Railway Review | No comments yet
The South Rail Systems Alliance achieved a historic milestone by completing the full renewal of the Severn Tunnel’s track in a single 16-day possession, marking a first for the rail industry.


Credit: Colas Rail
In a significant achievement for the rail industry, the South Rail Systems Alliance (SRSA) – a partnership between Colas Rail UK, Network Rail and AECOM – has announced that it has successfully completed a full renewal of the track within the Severn Tunnel in a single possession. This marks a first for the rail sector.
During a 16-day blockade, the SRSA’s Kings Norton division installed over 7,097 metres of new track on the down line, covering the entire length of the tunnel from the England entrance to Wales. The work had been executed using a phased renewal approach, breaking down the project into approximately 700m sections. This method allowed for continuous progress with multiple engineering trains and work fronts in operation.
Key figures from the project include:
- 7,097m of new track installed
- 66 rails, each 216m long
- 10,800 sleepers placed
- 22,000 tonnes of new ballast added
- 24,000 tonnes of spoil removed.
The operation was supported by the SRSA’s On Track Machine fleet, which utilised Tampers to finalize the track alignment. Additionally, the Freight Division had also been involved with 41 engineering trains used to transport materials and spoil.
Shaun Hodges, Head of Operations Wales and West at SRSA, said: “The meticulous planning and delivery work by our Kings Norton team, what we completed over 16 days, is an incredible achievement. Excelling at track installation is what we do best. Thank you to my team and everyone else who played their part in this success.”
Brian Paynter, Network Rail’s Track Programme Director, said: “With all the track in the tunnel now less than two years old, it is the best consistent condition than it has been for generations and certainly in the safest and tidiest condition as you have left it spotlessly clean. This is the longest single mobilisation conventional track renewal that anyone that I can remember, with the added complexity of working in what used to be the longest underwater tunnel in the world.”
The SRSA has developed a tradition of renewing the track in the Severn Tunnel, completing similar 10-day blockades in the summers of 2022 and 2023. The alliance, formed to manage a 10-year portfolio of works across the southern UK, continues to demonstrate its efficiency and expertise in the rail sector.
NEW REPORT FROM GLOBAL RAILWAY REVIEW: Track Insight – Track Maintenance | Transforming Track Maintenance Through Technology
Our latest expert-led Track Insight explores how industry leaders are revolutionising the future of track maintenance through cutting-edge innovation and real-world strategies.
From automation and robotics now streamlining inspections and repairs, to predictive maintenance powered by IoT sensors and advanced analytics, the rail sector is entering a new era of precision and efficiency. Companies like Goldschmidt, Bentley Systems, and MxV Rail are leading the charge, redefining how infrastructure is managed with AI, machine learning, and digital twins to reduce downtime and extend asset life.
In this new data-rich landscape, organisations such as Amtrak and the Rail Accident Investigation Branch are demonstrating how to turn vast streams of information—from track geometry to environmental monitoring into actionable intelligence for safer, smarter networks.
Download this insightful, practical guide for FREE and see how your operations can evolve – READ FOR FREE NOW!