Hi, please supply details of the number of signal failures on Tube lines for the past three years. Please include details for each set of signals (ie Earls Court or Edgware Road) about how long each outage lasted and if possible the cause of faults. Thanks

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TfL Ref: FOI-0752-1920

Thank you for your request received by Transport for London (TfL) on 12^th June 2019 asking for information about signal failures on the London Underground.

Your request has been considered in accordance with the requirements of the Freedom of Information Act and our information access policy.  I can confirm that we hold the information you require.

You asked:

“Please supply details of the number of signal failures on Tube lines for the past three years. Please include details for each set of signals (i.e. Earls Court or Edgware Road) about how long each outage lasted and if possible the cause of faults.”

The information is provided in the attached spreadsheet (you may need to widen some of the columns to see the data in full).  Note that the “duration” column is measured in minutes. In some instances, where the values are particularly high, the signal failure was managed using the imposition of a temporary speed restriction. While such instances are recorded as a signal failure under our categorisation and can last for several weeks, this does not necessarily reflect the effect felt by passengers with trains still able to operate, albeit with reduced speeds over the affected section of track.

We communicate delays to customers before they enter platforms by making public address announcements in the ticket hall areas and on platforms, displaying delays on electronic service update boards in ticket hall areas, writing on manual service update boards and free-standing general information boards, as well as via TfL’s website and our open data feeds. We also display delays on the dot matrix indicators (the illuminated black indicators on platforms). Note that under a major programme of modernisation, work has begun to install a state-of-the-art signalling system across the Circle, District, Hammersmith & City and Metropolitan lines at a cost of c£5.3bn. This will allow us to run trains closer together and will see reliability, frequency and journey time improvements across all four lines by 2023. The combination of new S-Stock trains and the new signalling system will see capacity increases of 33% across all four lines.

As part of our recent organisational change, a team whose sole focus is working on signalling issues has been created. We will continue to work on maintenance across many different aspects of ensuring reliability on the network, but this team will work to drive reliability and make sure that our customers’ priorities are at the forefront of all work we undertake to improve and maintain signals. We have continued to push for a reduction in ‘Service Affecting Faults’ across the signalling system and last year reduced the amount of signal failures by 12.9 per cent. 

More information about signalling and signal failures on the London Underground can be found on our website here:

https://tfl.gov.uk/campaign/tube-improvements/behind-the-scenes/signalling#on-this-page-1

If this is not the information you are looking for, or if you are unable to access it for any reason, please do not hesitate to contact me.

Please see the attached information sheet for details of your right to appeal as well as information on copyright and what to do if you would like to re-use any of the information we have disclosed.

Yours sincerely,

David Wells

FOI Case Officer

FOI Case Management Team

General Counsel

Transport for London

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