AÂ fault with the signalling system between Potters Bar and Alexandra Palace is causing disruption to Great Northern and Thameslink journeys running through these stations.
As a result, trains may be delayed by up to 15 minutes or revised.
Disruption is expected until 14:00.
Customer advice:
Some trains which run from Welwyn Garden City towards Moorgate will not stop at Hadley Wood or New Barnet. Your journey may take up to 15 minutes longer than usual.
Trains which run from Moorgate towards Welwyn Garden City are not affected and will call at these stations as scheduled.
It may be faster to reach your destination by circulating via another station:
- If you're at Hadley Wood or New Barnet and travelling towards London, you can instead travel to Potters Bar and change for a return service towards London.
- If you're travelling towards London and Hadley Wood or New Barnet is your destination, you can instead travel on to Oakleigh Park, then change for a return service which will call at all stations as normal.
Please remember to check journey planners and station information boards, and allow extra time to reach your destination.
Check the live map here to see if your journey has been affected.
Can you tell me more about the incident?
Due to a signal fault in the Hadley Wood area, trains are unable to use one of the available lines from Potters Bar towards Alexandra Palace. Trains can continue to run on the remaining available line towards London, but these trains will not call at Hadley Wood or New Barnet, as these stations do not have platforms accessible from the remaining line.
In this particular situation, the fault has been confirmed as a 'Track Circuit Failure'. This means the signalling system is unable to automatically verify if the next section of the track past the affected signal is clear.
The rail network is designed so that if a signal stops working, trains will stop before they reach it. Whilst this issue is ongoing, the train crew will stop at the affected signal and contact the signalling centre to confirm their location. At this point, the signaller will verbally authorise the driver to continue towards the next signal. This process adds time to every train's journey, leading to delays and disruption.
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.