Issue resolved: delays to Thameslink services between London St Pancras International and St Albans City expected until 12:00 

Route(s) affected

Between Brighton / Three Bridges and Bedford, and also between Rainham (Kent) and Luton, and also between Sutton and St Albans City

Description

Following a fault with the signalling system between London St Pancras International and St Albans City, all lines are now open. Trains running between these stations may still be delayed by up to 15 minutes.

Disruption is expected until 12:00.

Customer advice:

Disruption is expected between London St Pancras International and St Albans City. This is due to various signalling faults along the line. This is also affecting trains heading to Sutton via Wimbledon or Mitcham Junction.

If you are looking to travel or are currently travelling you will likely experience some delays. Trains may also be subject to last minute alterations. Please allow at least an additional 15 minutes time to complete your journey.

For the latest information, please check online journey planners and live departure boards or speak to station staff.

Planning your journey:

You can see live departure boards.

You can view a live map of the network.

You can also see alternative route guide.

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

The Thameslink app will also help you plan your journey.

Can you tell me more about the incident?

A track circuit failure will disrupt your journey between St Pancras International and St Albans City. This may also affect routes to Sutton via Wimbledon or Mitcham Junction.

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.