News story

Operational irregularity at Balham

Investigation into an operational irregularity at Balham, south-west London, 20 April 2019

This news article was withdrawn on

This item has been moved to the National Archives as RAIB has published its report into this incident. See Report01/2020.

Trackwork looking south west of Balham station

Trackwork looking south west of Balham station

An operational irregularity occurred just after 19:00 hrs on Saturday 20 April 2019 near Balham station, in south London. A passenger train, running from London Victoria to East Grinstead, passed across a junction less than two minutes before an engineering train that was travelling in the opposite direction. The engineering train, formed of an on track machine known as a tamper, was making an un-signalled move that had not been correctly authorised when it left a possession (in which a section of line had been closed to railway traffic to allow engineering work to take place). There were no injuries or other adverse consequence although, if the circumstances had been slightly different, there was the potential for the two trains to have collided.

Our investigation will seek to identify the sequence of events which led to the irregularity, and will consider:

  • the communications that occurred between those involved in planning, setting up and managing the movement of the tamper within, and when leaving, the possession
  • the actions of staff involved in managing the movement of the tamper, both locally and remotely, taking appropriate account of human factors
  • the information that was available to those who made decisions leading to the departure of the tamper from the possession
  • the adequacy of relevant rules and procedures, as well as the training, instruction, and competence management of the staff involved
  • any underlying management factors

Our investigation is independent of any investigation by the railway industry or by the industry’s regulator, the Office of Rail and Road.

We will publish our findings, including any recommendations to improve safety, at the conclusion of our investigation. This report will be available on our website.

You can subscribe to automated emails notifying you when we publish our reports.

Published 8 May 2019