Request ID: FOI-3324-2223 Date published: 31 March 2023
You asked
Follow-up to EIR-2972-2223: Thank you for indicating the work being done.
Please confirm:
- how far North and South of the station is flatbottom rail being placed and in which direction (northbound / southbound / both?)
- what is being done in the station itself?
[ to explain: Inside the station the rail sits on pit blocks on piers, not sleepers. It is therefore not clear if these are suitable for flatbottom rail as well. ]
- the level of noise & vibration that can be expected following the works completion
We answered
TfL Ref: EIR-3324-2223
Thank you for your request received by Transport for London (TfL) on 9th March 2023 - as amended on 30th March 2023 - asking for information about track works on the Northern Line.
Your request has been considered in accordance with the requirements of the Environmental Information Regulations.
On 9th March you asked the following, in relation to the previous response given under case ref EIR-2972-2223:
“Please confirm:
- how far North and South of the station is flatbottom rail being placed and in which direction (northbound / southbound / both?)
- what is being done in the station itself?
[ to explain: Inside the station the rail sits on pit blocks on piers, not sleepers. It is therefore not clear if these are suitable for flatbottom rail as well. ]
- the level of noise & vibration that can be expected following the works completion”.
On 30th March you sent an email stating that the question "....- what is being done in the station itself? [ to explain: Inside the station the rail sits on pit blocks on piers, not sleepers. It is therefore not clear if these are suitable for flatbottom rail as well. ]” is now withdrawn
I can confirm that we hold some of the information you require. Your questions are answered in turn below:
Question1: how far North and South of the station is flatbottom rail being placed and in which direction (northbound / southbound / both?)
Answer: The re-rail started just inside the departure headwall of Chalk Farm Northbound platform (only 9m of platform length affected) and continued 993m into the northbound tunnel towards Belsize Park.
Question 2: The level of noise & vibration that can be expected following the works completion
Answer: We do not hold recorded information to answer this and we cannot put a figure on it. However, engineering colleagues tell me that they have seen a marginal improvement in the levels where the rails have already been converted to the flat bottom type.
Note that your request for new information in your email of 30th March 2023 will be logged as a separate request and addressed accordingly.
If this is not the information you are looking for 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
