A fault with the signalling system between London Blackfriars and London St Pancras International means that trains have to run at a reduced speed on some lines. Trains running between these stations may be cancelled, delayed by up to 30 minutes or revised.

Disruption is expected until the end of the day.

Customer Advice

Due to a fault with the signalling system between London Blackfriars and London St Pancras International, you should allow up to 30 minutes extra to complete your journey this afternoon.

How will this affect my journey?

North of London:

• Services between London St Pancras International and Peterborough may have delays due to stopping at additional stations South of London
• Services between London St Pancras International and Cambridge may have delays and alterations to the stopping patterns, you may have to change trains to get to your destination
• Services between London St Pancras International and Bedford will have a reduced service. You may need to wait for the next available service if your original train is too busy to board

Central London

• Services between Sevenoaks and Welwyn Garden City will operate between Sevenoaks and London Blackfriars only
• Services that run between Sutton and St Albans / Bedford - there will be some cancellations with delays and alterations to the stopping patterns
• Services between Orpington and Luton are cancelled

South of London

• Services between East Grinstead and Bedford are cancelled. If you require travel to / from East Grinstead, you can use alternative Southern services between London Victoria and East Grinstead
• Services between Brighton and central London will be delayed. There is a reduction of services between Three Bridges and central London so you may need to wait for the next available service
• Services between Horsham and Peterborough will be delayed. These may have alterations to call additionally at Salfords and Earlswood

Please check station screens and planners for the latest information for your next service.

This disruption will also affect the return working of the delayed trains, causing knock on delays to trains travelling south through London.

If you are travelling to either Gatwick Airport and Luton Airport please ensure you leave enough time to reach your destination, as there is a reduced service between Bedford and Gatwick Airport.

Ticket acceptance:

Waiting for the next train should be your quickest option, however, the following ticket acceptance has been arranged, at no extra cost to you:

• London Underground via any reasonable route
• London Buses via any reasonable route
• Great Northern trains between London Kings Cross and Peterborough / Cambridge
• Southern trains between Brighton and London Victoria
• Southeastern trains between Rainham and London via any reasonable route

Planning your journey:

The live departure boards can be found here.

You can view a live map of the network here.

You can also see the alternative route guide here.

If you're travelling in the London area, you can plan journeys on alternative routes by using the TfL Journey Planner here.

Can you tell me more about the incident?

A track circuit failure is disrupting trains travelling northbound between London Blackfriars and London St Pancras International.

This part of the network uses track circuits to detect the position of trains. These are electrical systems which monitor whether a train is on a section of track. They operate as part of the signalling system, which is designed to be "fail safe".

When a track circuit fails, the signalling system will interpret this as a train remaining in place, even though there may not be a train present at all, or the previous service may have long since left the area.

As a result, further trains cannot be automatically allowed onto the relevant section of track. Train drivers will be stopped by red signals on approach. They will then get verbal permission from the signaller so that they can proceed, and will run at a heavily-reduced speed as far as the next signal. This is so that the drivers will stop safely if they see anything ahead of them.In some areas, the sections between signals can be several miles long, so this can result in delays building up. Even with shorter sections of track affected, there would still be a delay of at least a few minutes to each journey.

Track circuit faults can be caused by a number of different issues, including electronic faults or obstructions on the track. Network Rail manage the signalling system, including track circuits, and their staff will be investigating as quickly as possible.

Check before you travel:

You can check your journey using the National Rail Enquiries real-time Journey Planner.

​​​​​​​Compensation:

You may be entitled to compensation if you experience a delay in completing your journey today. Please keep your train ticket and make a note of your journey, as both will be required to support any claim.