Rail passengers between Carmarthen and Swansea are being advised of disruption from Friday 31 October through Sunday 2 November as Network Rail carries out essential signalling upgrades. Buses will replace trains while engineers complete the modernisation works designed to improve safety, reliability, and operational efficiency.

The work forms part of phase two of Network Rail’s Port Talbot West resignalling project, which is transitioning the route to digital technology. Over the past two and a half years, 59 signalling failures have occurred between Carmarthen and Llanelli, highlighting the need for upgraded infrastructure. The improvements include level crossing enhancements, upgraded train control systems, and modernised operations to reduce delays for both passengers and freight operators.

During the weekend work:

• Four traditional signal boxes at Pembrey, Kidwelly, Ferryside, and Carmarthen Junction will be retired, with operations moving to remote digital control from Port Talbot.

• Level crossing upgrades will include new barriers, obstacle detection systems, and refreshed road markings. On-site attendants will remain at Kidwelly, Bertwyn, and Ferryside crossings until December/January while commissioning of the new equipment takes place.

• The Pembrey relay room adjoining the former signal box will be demolished.

• Semaphore signals will begin to be removed, with remaining structures to be dismantled and repurposed across the region in the coming months.

“These works mark a transformative moment for rail operations in South West Wales,” said Scott Beech, Project Manager. “By centralising control and upgrading our signalling infrastructure, we’re not only improving reliability but also laying the groundwork for a safer and more responsive railway system that better serves our communities. We thank passengers in advance for their patience while this vital work is carried out.”

Additional closures between Swansea and Carmarthen are planned for Sundays 16 and 23 November to complete the final stages of the upgrade, which is part of Network Rail’s wider programme to strengthen infrastructure, improve safety standards, and support more reliable journeys across the Wales and Borders route.

Image: Network Rail