Great Western Railway passengers will encounter significant rail disruptions starting November 28, 2026, as Network Rail initiates a £27.8 million infrastructure upgrade at Dolphin Junction in Slough. The work includes replacing ageing equipment on the eastern side of the junction, improving track layout, upgrading overhead line equipment, and deep cleaning London Paddington station. Dolphin Junction handles over 400 trains and 100,000 passengers daily, making this upgrade critical for future reliability.
November 28-29 Weekend Works and Service Changes
On the weekend of November 28 and 29, 2026, Network Rail will carry out replacement of the eastern part of Dolphin Junction, causing complete suspension of Great Western Railway services
to and from London Paddington. Elizabeth Line will reduce its service to operate only between Reading and Maidenhead, with no service between Maidenhead and Abbey Wood or between Heathrow Airport and Shenfield. Heathrow Express and Elizabeth Line will not run any trains to or from Heathrow Airport during the same weekend.
Replacement bus services will operate between Ealing Broadway and Slough, extending to Burnham, Taplow, and Maidenhead. Branch line trains under GWR will continue running on routes from Slough to Windsor & Eton Central, Maidenhead to Marlow, and Twyford to Henley-on-Thames. GWR is also operating a special fast direct service
between Reading and Guildford on this weekend to connect with South Western Railway trains to London Waterloo.
December and New Year Service Suspensions
Christmas Day 2026 will see no passenger train services across the national rail network, with most services suspended on Boxing Day. Between December 27 and 30, 2026, Elizabeth Line will not run between London Paddington and Reading, and GWR will similarly suspend services between Paddington and Slough. During this period, passengers may travel on London Underground services between Paddington and Ealing Broadway and use replacement buses between Ealing Broadway and Slough. Elizabeth Line and Heathrow Express will not provide services to Heathrow Airport
until December 30, 2026; the Piccadilly line will operate as the sole rail link to the airport during this time.
From December 31, 2026, through January 3, 2027, Elizabeth Line will not run between Hayes and Harlington and Reading, with replacement services arranged. On January 3, replacement buses will operate between Hayes and Harlington and stations serving Maidenhead with customer transfer options at Maidenhead for Great Western Railway services to and from Reading. GWR branch services between Slough and Windsor & Eton Central, Maidenhead and Marlow, and Twyford and Henley-on-Thames will continue operating during these disruption periods.
Additional Service Details and Rugby Event Impact
Chiltern Railways will
maintain its services between London Marylebone and High Wycombe, Oxford, and Banbury throughout the disruption. South Western Railway expects particularly busy trains running between London Waterloo and Windsor & Eton Riverside or Reading during the holiday period due to international rugby matches at Twickenham, especially on December 28, 2026.
Project Justification and Passenger Advice
Ross Mahoney, Network Rail’s Great Western route project director, said Dolphin Junction is among the busiest sections of the Great Western Main Line, with thousands of daily passengers traveling between London, the Thames Valley, the South West, and Wales. He explained the upgrades will replace old points and infrastructure with modern
technology and a improved track layout to reduce congestion and provide more reliable journeys. Mahoney acknowledged the short-term disruption caused by the works and thanked passengers and freight customers for their patience. He stated the upgrades will support a more dependable railway and smoother operations for years to come.
Passengers using affected routes should anticipate significant timetable changes, cancellations, and delays during the outlined periods. Extra travel time is recommended, and journey planners available at GWR.com/Upgrade and nationalrail.co.uk/dolphinjunction have been updated through January 4, 2027. Network Rail has scheduled further improvements affecting London Paddington services on January 10, 2027.
