Disruption between Balham / Tulse Hill and Sutton expected until 17:00 

Route(s) affected

Southern between London Bridge and Epsom, and also between London Victoria and Epsom Downs / Dorking / Horsham

Thameslink between St Albans City and Sutton (Surrey)

Description

A fault with the signalling system between Balham / Tulse Hill and Sutton means that all lines are blocked. As a result, services between these stations may be cancelled, delayed by up to 25 minutes, diverted or revised.

Trains will take at least an extra 25 minutes to reach Sutton when diverted via West Croydon. Please allow for this when planning your journey.

This is expected until 17:00.

Customer advice:

Services that run between Tulse Hill and Sutton will be disrupted by a signalling failure. This disruption is expected to last until late afternoon / early evening. Trains will take at least an extra 30 minutes to reach Sutton when diverted via West Croydon. Please allow for this when planning your journey.

How are Thameslink changing their service?

While this disruption is ongoing, Thameslink will be making the following changes to their services:

Trains that normally run between St Albans and Sutton Via Wimbledon will be cancelled until further notice.

How do I travel from Sutton to London?

If you are travelling to London from Sutton you can use your ticket on an Alternative Southern service to London Victoria.

What if I'm travelling between Carshalton and Streatham?

If you're travelling Northbound from Sutton and require stations between Carshalton and Streatham (including stations via Wimbledon or Mitcham Junction), you can use your existing ticket at no extra cost on London Trams or London Buses.

If you're travelling Southbound and require stations between Streatham and Carshalton (including stations via Wimbledon or Mitcham Junction), you will need to change at Streatham and use your existing ticket at no extra cost on London Buses to complete your journey.

Ticket Acceptance:

You can use your existing ticket at no extra cost on the following services:

• Alternative Southern / Thameslink Services between the South coast and London

• South Western Railway between Epsom, Wimbledon and London

• London Underground between all terminals

• London Buses between East Croydon and Clapham Junction

• London Trams between East Croydon and Wimbledon/Mitcham Junction

Planning your journey:

Live departure boards can be found.

You can view a live map of the network.

You can also see the alternative route guide.

Can you tell me more about the incident?

An axle counter failure will disrupt your journey in the Streatham area.

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.