London Paddington is heading into a significant period of rail disruption as engineering work at Dolphin Junction closes the railway on key dates this winter. The programme will affect Great Western Railway, Heathrow Express and Elizabeth line passengers, with the first major closure scheduled for 28 and 29 November 2026.
The work is centred on Dolphin Junction between Slough and Langley. National Rail says the project involves replacing and enhancing the eastern side of the junction, including a new track layout, overhead electrification equipment, signalling infrastructure and upgraded points equipment.
For passengers travelling between central London, Heathrow, Reading and destinations across the West of England, the changes will require careful planning.
Paddington Will Close To Trains
The November closure is particularly significant because no trains will run between Maidenhead and London Paddington in either direction on Saturday 28 and Sunday 29 November.
That affects all routes into Paddington covered by the engineering closure. Network Rail’s current Paddington information also confirms that only London Underground services will operate to and from the station during that weekend.
The closure means passengers normally relying on Paddington for GWR, Heathrow Express or Elizabeth line journeys will need to use alternative routes.
For visitors arriving in London with luggage, the disruption could be especially relevant because Paddington is one of the capital’s main gateways for Heathrow Airport and western England.
GWR Services Will Be Reworked
Great Western Railway services will operate differently during the November closure.
National Rail says services from Bristol and South Wales towards London will either terminate at Reading or use an alternative route towards London Euston. Some South West and West of England services will also terminate at Reading, while Cheltenham Spa services will terminate at Swindon.
Passengers travelling between Reading and central London will have alternative options.
A special GWR service will operate between Reading and Guildford, allowing passengers to connect with South Western Railway services between Guildford and London Waterloo. However, the route is expected to be busy, with a major rugby event taking place at Twickenham during the same weekend.
This means travellers should allow additional time rather than treating the alternative route as a like-for-like replacement.
Heathrow Airport Connections Are Affected
The disruption extends directly to Heathrow.
Heathrow Express will not operate between Paddington and Heathrow Airport during the 28 and 29 November closure.
The Elizabeth line will also face major changes.
Only a limited Elizabeth line service of two trains per hour will operate between Reading and Maidenhead. There will be no Elizabeth line service between Maidenhead and Abbey Wood, or between Heathrow Airport and Shenfield, during the weekend.
Replacement buses will operate on sections of the affected network, including between Maidenhead and Slough and between Slough and Ealing Broadway.
Passengers travelling between Heathrow and central London should therefore check the route before leaving the airport.
Christmas Brings Another Major Closure
The disruption does not end in November.
Further engineering work is scheduled around the Christmas and New Year period, when the railway will already be operating under its traditional festive engineering programme.
The Dolphin Junction project will contribute to closures from 27 December 2026 through 3 January 2027, following the usual Christmas shutdown on 25 and 26 December.
That creates a particularly important travel window for visitors heading into London after Christmas or travelling west for New Year celebrations.
The exact service pattern will depend on the final engineering timetable, so passengers should check their journey shortly before travelling.
Why Dolphin Junction Matters
The work is not simply routine maintenance.
Dolphin Junction is an important part of the railway between the Thames Valley and London. National Rail says the project is designed to reduce congestion and improve reliability by allowing trains to enter, change lines and leave the junction at greater speed.
The eastern side of the junction is being upgraded after earlier work on its western side during Christmas 2025.
The project includes a new track arrangement, changes to overhead power equipment and the relocation of signalling infrastructure. Points operating equipment is also being upgraded.
The temporary disruption is therefore connected to a wider effort to improve how trains move through this busy section of the Great Western network.
Travellers Should Plan Around The Closures
For tourists, business travellers and airport passengers, the most important dates are 28–29 November 2026 and 27 December 2026–3 January 2027. Anyone with a flight from Heathrow should avoid assuming that Paddington-to-Heathrow rail services will operate normally. Similarly, passengers travelling to Bristol, South Wales, Oxford, Reading or the South West should check whether their train will terminate early, be diverted or require a connection. Paddington remains one of London’s major transport hubs, with GWR, Heathrow Express and the Elizabeth line all serving the station. The Dolphin Junction upgrade will temporarily disrupt that network, but the purpose is to improve the railway’s capacity and reliability for future journeys. For travellers, the key message is simple: check the timetable before travelling, allow extra time and avoid building tight airport or long-distance connections around Paddington on the affected dates.
