Engineering work not being finished in time between Potters Bar and New Barnet means some lines are blocked.
Trains between Potters Bar and Alexandra Palace may be cancelled, delayed or revised. Disruption is expected until 04:00 on Tuesday 9 March.
Customer Advice
Engineering works have not been completed on time between Potters Bar and New Barnet. This means one of the two lines towards London will be closed throughout the day on Monday, 8 March.
From 22:00 on Monday evening until the early hours of Tuesday, there will then be a closure of both London-bound lines to allow the works to be completed.
This means there will be disruption to Thameslink and Great Northern services on routes via Finsbury Park. Please check the advice below, use a journey planner to find the times for your journey, and leave some extra time.
From the start of the day until 22:00:
Stopping services from Welwyn Garden City towards Moorgate will run non-stop between Potters Bar and Oakleigh Park, not stopping at Hadley Wood or New Barnet.
Trains towards Welwyn Garden City will still be able to stop at the usual stations.
We also expect there to be some minor delays to other Thameslink and Great Northern services via Finsbury Park, as more trains will share the line towards London which is remaining open.
A bus service will run from Potters Bar, calling at Hadley Wood, New Barnet and Oakleigh Park. Buses will take longer than the usual train services.
If there are any other changes, we'll let you know how this affects your journey.
After 22:00:
Where possible, trains between Stevenage and London will be diverted on the route through Hertford North. This will also take longer than usual.
The train diversions will mean there will be no London-bound trains at Knebworth, Welwyn North, Welwyn Garden City, Hatfield, Welham Green, Brookmans Park, Potters Bar, Hadley Wood, New Barnet, Oakleigh Park or New Southgate.
There will also be some cancellations, and some changes to trains in the opposite direction. This because our trains and crews will no longer be in the correct places, and most of the route used by our Welwyn Garden City-Moorgate services will be closed by this.
We are working to confirm the best options for your journey, including rail replacement bus services and ticket acceptance on alternative routes.
Can you tell me more about the incident?
Over the weekend, Network Rail have been carrying out major engineering works, including track replacement work in the Potters Bar Tunnel area, just south of the station.
Rails and sleepers (which carry the rails) eventually require replacement due to the weight of trains travelling over them on a frequent basis. This is part of an essential programme of maintenance which continues all year, around the clock.
Engineering works are always closely monitored to check progress. During the day on Sunday, it became apparent that the works could not be completed in time to reopen the railway in the early hours of Monday morning. Engineers are able to safely reopen three of the four lines in the area, but the line usually used by southbound stopping trains will remain shut.
Follow-up works have already been planned to take place overnight from Monday into Tuesday. Until this time, only one line towards London will be open through Hadley Wood and New Barnet. If express and stopping services had to share this line, it would lead to major delays, as there is a great difference between the speeds of local and long-distance services. For this reason, trains won't be able to call at these stops when travelling towards Moorgate.
Network Rail will be thoroughly investigating the cause of the engineering works taking longer than planned. In the meantime, we're working with them to run as reliable a service as possible, and provide alternatives where trains can't run according to the timetable.
Check before you travel:
You can check your journey using the National Rail Enquiries real-time Journey Planner
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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.
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