South Rail Systems Alliance completes historic track renewal in Severn Tunnel

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.