The impact of Mid Tunnel Vent Shafts on temperature on the Victoria Line
Request ID: FOI-2189-2223 Date published: 22 December 2022
You asked
Hi all,
Please could you provide all the data you have regarding the impact that Mid-Tunnel Vent Shafts have on the temperature on the Victoria Line.
I would be interested to know what reading you have taken whilst the MTVS aren't running and how this compares to temperatures taken while the MTVS are in operation.
Please could I receive the information within the period between 2012 to present?
We answered
TfL Ref: FOI-2189-2223
Thank you for your request received on 1 December 2022, asking for information about a mechanical ventilation shaft on the Victoria Line.
Your request has been considered in accordance with the requirements of the Freedom of Information (FOI) Act and our information access policy. You specifically asked:
Please could you provide all the data you have regarding the impact that Mid-Tunnel Vent Shafts have on the temperature on the Victoria Line. I would be interested to know what reading you have taken whilst the MTVS aren't running and how this compares to temperatures taken while the MTVS are in operation. Please could I receive the information within the period between 2012 to present?
Unfortunately we do not hold the information you have requested. We don’t have any data that shows the mechanical ventilation shaft on/off operations against the platform temperature measurements for the Victoria Line.
Mid tunnel ventilation shafts (MTVs) are used to manage thermal conditions on the underground and to provide additional ventilation. Therefore, we don’t turn them off to test the effect on thermal conditions. Whilst we have not directly tested the effect of turning the MTVs off on the operational railway, the impact is considered by our Engineering teams to be in the region of 1 to 2 degree Celsius (increase in platform temperatures if off), with other factors such as train service levels, ambient temperatures, and duration of shut down influencing the local effects seen at adjacent stations.
Temperatures as provided on the GLA website (https://data.london.gov.uk/dataset/london-underground-average-monthly-temperatures) for the Victoria Line during the warmer summer periods between 2013 and 2020 show that such an increase in temperatures would be highly undesirable and therefore every effort is made to keep these assets operational at all times.
Please see the attached information sheet for details of your right to appeal.
Yours sincerely
Eva Hextall FOI Case Management Team General Counsel Transport for London
