Disruption between London Blackfriars and London St Pancras International expected until 10:00 

Route(s) affected

Between Brighton / Haywards Heath / East Grinstead / Three Bridges / Rainham (Kent) and Bedford, and between Brighton and Cambridge, and between Gillingham (Kent) / Orpington / Elephant & Castle and Luton, and between Horsham and Peterborough, and between Sutton and Kentish Town, and between Orpington / Rainham (Kent) and West Hampstead Thameslink, and between Sevenoaks and Finsbury Park / Welwyn Garden City, and between Sutton and St Albans City

Description

A fault with the signalling system between London Blackfriars and London St Pancras International means that fewer trains than normal are able to run on the line towards London St Pancras International.

As a result, services running between these stations may be cancelled, delayed by up to 30 minutes or revised.

Disruption is expected until 10:00.

Customer advice:

If you are travelling between London Blackfriars and London St Pancras International, you may need to change trains and allow extra time to arrive at your destination. This is due to a fault with the signalling system.

Your journey may take longer than normal and you should allow an additional 30 minutes extra to reach your destination.

For the latest information, check station screens and use our online journey planners.

How the service will be affected:

Additional Peak time services that normally run between East Grinstead and Bedford, Orpington and West Hampstead Thameslink or Orpington and Luton have been cancelled.

Services that normally run between Three Bridges and Bedford have been cancelled.

Some further services that normally run between London Blackfriars and London St Pancras International may be cancelled, or may terminate and restart at earlier stations. Please make sure to check your journey before you travel today

Services are also expected to be affected by delays of at least 30 minutes this morning.

Please talk to station staff, look at information boards or check your journey planner for the latest information.

Your ticket will be accepted at no extra cost on:

• Alternative Thameslink services between Bedford / Peterborough / Cambridge and Brighton / Sevenoaks / Orpington

• London Underground services between London Blackfriars and London St Pancras International

Planning your journey:

For help planning your journey, check live departure boards, view a live network map or see alternative route guides.

If you’re travelling within London, you can use the TfL Journey Planner.

Stay up to date on the move with Thameslink's WhatsApp channel. Live updates are available Monday to Friday, 07:00–21:00.

Can you tell me more about the incident?

This part of the network uses axle counters to detect whether trains are in the area. These are electrical systems which check the passage of train wheels and 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 an axle counter 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.

Axle counter faults can be caused by a number of different issues, including electronic faults and debris coming into contact with them. Network Rail manage the signalling system, including axle counters, and their staff will be investigating as quickly as possible.

Check before you travel:

You can check your journey using the National Rail 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.