TfL Ref: 2365-1920

Thank you for your request received by us on 5 November 2019 asking for information about London Underground’s Central line.

Your request has been considered in accordance with the requirements of the Environmental Information Regulations and our information access policy. I can confirm that we hold some of the information you require. You asked for:

information on TfL's policy on line cleaning and its effectivenes (as TfL always claims this may not be effective although my experience is that is very effective) and how often it plans to clean sections, or does clean sections, of the Tube such as the Central Line between Bethnal Green and Mile End.

Whilst there is no policy as such for ‘rail grinding’, whereby as the rails are ground, dust and particles are extracted accordingly, it is primarily a tool used to address rail defects and prolong the life of the rail thus keeping it in a safe condition. As mentioned in our previous responses, although rail grinding is not deemed as an engineering method to reduce noise, some residents have experienced a reduction in noise levels following grinding.

However, we undertake assessments on specific track sections where noise levels are reported as a concern, and wherever possible complete appropriate noise-reducing works. Additional funding has been made available to implement a number of immediate and longer-term solutions to reduce in-tunnel noise. This includes the implementation of an enhanced programme of rail grinding, which triples the volume of grinding at prioritised sites. This has now been completed on the Central line, with readings indicating a reduction in the noise levels experienced.

Engineering options to reduce noise levels inside London Underground’s tunnels are limited. TfL undertakes assessments on specific track sections where noise levels are reported as a concern, and wherever possible completes appropriate noise-reducing works. For example, there are sections of track on the Northern line with corrugation (high rail roughness), and therefore the wheel-rail interface rolling contact may cause higher levels of noise. We maintain a rail grinding programme to address areas of highly corrugated track, but this can only achieve temporary improvements. One particular effect of corrugation on the rail is that the energy created causes noise that can be heard in residential properties. To address this we have used a track dampening system which has significantly lowered the noise levels recorded in local homes but created uncomfortable noise being experienced by our customers as a result.

Our current Central Line Grinder Programme shows that works were carried out on 27 and 29 August 2019 and that further works are planned for 30 and 27 January 2020 as well as 2 March 2020.

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

Jasmine Howard
FOI Case Officer
Information Governance
Transport For London