The North Wales Coast railway line will close for four weeks in early 2027 as part of a £25m investment programme described as "once in a generation". Network Rail will carry out upgrades to improve reliability, capacity and safety on the route between Chester and Holyhead, which carries both passengers and freight.
Engineers will work at several points along the line, replacing track and other infrastructure, some of which has been in place for more than 50 years. To allow the work to be done safely, the line will shut from Saturday, January 9, until Saturday, February 6, 2027.
Closure details and rail replacement services
During the first three weeks, the railway will be closed between Chester and Holyhead, including the Conwy Valley line and the Llandudno Junction to Llandudno branch. In the fourth week, the closure will be reduced to between Llandudno Junction and Holyhead.
Network Rail said it has worked with its engineering teams to shorten the Chester to Llandudno Junction closure from four weeks to three, and continues to work with industry partners to minimise disruption. Rail replacement services will run throughout the closure, with full travel arrangements expected to be confirmed in autumn 2026.
What the £25m investment includes
The investment includes work using 22 engineering trains and specialist on-track equipment, transporting more than 3,000 concrete sleepers and 9,000 tonnes of ballast, and removing approximately 9,800 tonnes of spoil for recycling and reuse on future railway schemes. The work follows the introduction of the new north Wales timetable in May 2026, which brought a 50% increase in Transport for Wales services.
Completing the work within a single four-week programme will reduce the need for repeated weekend closures in future, limiting disruption for passengers, residents and local businesses.
Official response
Emma Osborn, passenger strategy director at Network Rail Wales and Borders route, said: "This is a once-in-a-generation investment in the North Wales Coast railway and a huge opportunity to renew and improve infrastructure right across this vital route." She added that the long-term benefits "will far outweigh this temporary disruption, with a safer, more reliable railway that is better equipped to support the increased number of services now running across North Wales."
Colin Lea, planning and performance director for Transport for Wales, said: "Essential track maintenance, tunnel drainage, and new accessible footbridges will help deliver a more reliable service and better stations for the communities we serve." Chris Liptrot, operations director at Avanti West Coast, said customers planning to travel during the period are advised to check the Avanti West Coast and National Rail Enquiries websites for the latest travel information.
