Signalling faults on the rail network are causing major disruption for London commuters this morning.
Trains between Luton and London St Pancras International have been running at reduced speeds due to a fault near Radlett, with delays of up to 45 minutes and cancellations expected until at least 3pm.
In an update this afternoon, Network Rail confirmed the issue has been resolved, though disruption is expected until 4pm.
It comes after disruption at London Marylebone earlier on Wednesday, after another signalling system fault hit services during the morning rush.
Meanwhile, no issues were being reported on the London Underground.
Follow the latest updates below...
Major disruption expected following signalling issue at London Marylebone
Wednesday 15 April 2026 08:41 , Megan HoweAn earlier signalling fault at London Marylebone railway station is causing major disruption on the network.
All lines have reopened, but trains are still having to run at a reduced speed through the area.
Delays of up to 30 minutes are expected as a result. Some services may be revised or cancelled.
Major disruption is expected until 09.30am.
Good service on all London Underground lines
Wednesday 15 April 2026 08:44 , Megan HoweOn a positive note, there is good service across the London Underground network this morning.
Which routes are affected by delays?
Wednesday 15 April 2026 08:58 , Megan HoweChiltern Railways services between Stourbridge Junction, Birmingham, Banbury, Kings Sutton, Oxford, Aylesbury, Princes Risborough, High Wycombe, Gerrards Cross, West Ruislip, and London Marylebone are affected by the disruption this morning.
Anyone travelling to these stations has been advised to take CrossCountry, Avanti West Coast, GWR, or LNWR services travelling north.
Passengers can use the same ticket. Services depart from London Euston station.
Major disruption expected until 10am
Wednesday 15 April 2026 09:26 , Megan HoweMajor disruption at London Marylebone is now expected until 10am.
Passengers are advised to seek alternative routes where possible.
You can check your journey in advance using the National Rail Journey Planner.
Disruption expected until 11.30am
Wednesday 15 April 2026 10:16 , Megan HoweDisruption at London Marylebone is now expected until 11.30am after a signalling fault brought services to a halt this morning.
Second signalling fault at London station causing travel chaos
Wednesday 15 April 2026 10:55 , Megan HoweA second signalling fault on the rail network this morning is causing delays to Thameslink and East Midlands Railway services running between Luton and London St Pancras.
A fault at Radlett means trains are having to run at a reduced speed on all lines.
Trains running between Luton and St Pancras International may be cancelled, revised, or delayed by up to 45 minutes
Disruption is expected until 1pm.
Fault on a train at London Bridge
Wednesday 15 April 2026 11:37 , Megan HoweA fault on a train at London Bridge means that some lines are blocked.
Trains running through London Bridge may be delayed by up to 20 minutes, cancelled or revised.
Disruption is expected until 12.15.
Major disruption between Luton and St Pancras expected until 3pm
Wednesday 15 April 2026 12:38 , Megan HoweAs we reported earlier, a signalling fault at Radlett is causing major disruption between Luton and St Pancras.
Trains are having to run at reduced speed on all lines.
Services may be cancelled, revised, or delayed by up to 45 minutes as a result.
Major disruption is expected until 3pm.
Signalling issue at St Pancras is resolved but disruption expected until 4pm
Wednesday 15 April 2026 13:16 , Megan HoweThe signalling issue has now been resolved, Network Rail has said, although disruption is expected to last until 4pm today.
East Midlands Railway between Sheffield, Nottingham, Corby, and London St Pancras International.
Thameslink between Bedford and Three Bridges, Brighton, between Luton and Orpington, Rainham and also between St Albans City and Sutton.
