Lines have reopened following a number of incidents in the Hadley Wood area. Trains running between Stevenage and Finsbury Park may still be delayed by up to 30 minutes.

Disruption is expected until 21:00.

Customer Advice:

Trains can now run through the Hadley Wood area once more, however there will be delays, alterations and cancellations to services whilst Great Northern and Thameslink work to get their stock and crew back to their working timetable.

Please allow an extra 30 minutes to complete your journey, and check station screens and planners for the latest information.

Ticket acceptance

Your ticket will be accepted on the following, at no extra cost:

• London Buses between Potters Bar and London Kings Cross
• mutually between Thameslink and Great Northern
• London Underground between London Kings Cross and Cockfosters
• Greater Anglia services between Cambridge and London Liverpool Street for connections into Central London

Planning your journey:

You can check train departures from your station here:

• Thameslink live departure boards
• Great Northern live departure boards

You can view live maps of our network here:

• Thameslink live route map
• Great Northern live route map

You can also see our alternative route guides here:

• Thameslink alternative route guide
• Great Northern alternative route guide

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?

Great Northern and Thameslink had a number of trains come to a stand due to a failure of the electricity supply in the Hadley Wood area earlier today. Although the power was restored one of the trains was unable to move until fitters attended, causing a queue of 5 trains behind. All trains are now on the move although there will be ongoing delays, alterations and cancellations as they work to get their stock and crew back to their working times.

Additionally to this, there is a track circuit failure in the Ely area that is delaying trains in the area.

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.