FOI request detail

Ventilation tunnels/shafts

Request ID: FOI-3211-2223
Date published: 27 March 2023

You asked

I would like a list of all the tube ventilation tunnels/shafts that exit onto street level. Clarification 6/3/23 I would like to know where your public and non-public ventilation shafts are. I am only looking for the exit/exhaust ventilations shafts, not inlet shafts.

We answered

TfL Ref: FOI-3211-2223

Thank you for your clarified request which we received on 6 March 2023, asking for information about public and non-public ventilation shafts.

Your request has been considered in accordance with the requirements of the Environmental Information Regulations (EIRs) and our information access policy.  I can confirm that we hold the information you require.

However, we consider that releasing a list of all the tube ventilation shaft points into the public domain would be prejudicial to national security and public safety, through the knowledge of where access may be gained outside our normal controlled routes.

This information is exempt from disclosure by virtue of Regulation 12(5)(a) of the EIRs, which provides that information can be withheld when its disclosure would adversely affect international relations, defence, national security or public safety. 

Although some of this information you asked about is already publicly available and some points can be identified above ground by those who know what they are looking for, this is quite different from TfL knowingly and deliberately making all this information available in a single list. It is an important principle of the FOIA and EIRs that disclosures are considered to be made to the general public and not just to the person making the request.

Disclosure of this information could assist any persons wishing to disrupt London’s transport infrastructure by placing into the public domain information which would otherwise not be available via other means. This information would be of considerable use to anyone planning terrorist attacks on the London Underground network, which would have clear consequences for public safety. The risk of such attacks is clearly not a hypothetical or remote possibility. There is a real and ongoing risk, particularly of terrorist attack, on the London Underground, and we must take reasonable steps to safeguard the security of our staff and the travelling public.

Regulation 12(5)(a) is a qualified exception, which means that TfL must consider the balance of the public interest. While we appreciate the expectation of transparency from public bodies, in this instance we do not consider that there are any other significant factors in favour of the release of this information. On the other hand, there are significant public interest factors in favour of limiting the amount of extra operational information that is made public as outlined above.

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

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