Delays to Great Northern services between Cambridge and Ely expected until 15:00 

Route(s) affected

Between London Kings Cross and Ely / Kings Lynn

Description

A fault with the signalling system between Cambridge and Cambridge North means trains will run at a reduced speed. Trains running between Cambridge and Ely may be delayed by up to 20 minutes.

Disruption is expected until 15:00.

Customer advice:

You can use your planned route to travel, but services are being delayed by up to 20 minutes.

Please make sure to check your journey and allow extra time to travel.

Planning your journey:

You can check your journey using the live departure boards, and you can view a live map of the network.

You can also see an 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 Great Northern app will also help you plan your journey.

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 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.