Frequencies and Durations of Door Buzzer sounds on the D78 Stock, 1992 Stock, 1996 Stock, and S Stock
Request ID: FOI-3605-2324 Date published: 18 January 2024
You asked
Dear TfL,
Could you please tell me the frequencies and durations of the door buzzer sounds when doors open and close on the D78 Stock, 1992 Stock, 1996 Stock, and S Stock trains?
Thank you.
We answered
TfL Ref: FOI-3605-2324
Thank you for your request received by Transport for London (TfL) on 10th January 2024 asking for information about the frequencies and durations of door buzzer sounds on the D78 Stock, 1992 Stock, 1996 Stock, and S Stock.
Your request has been considered in accordance with the requirements of the Freedom of Information Act and our information access policy.
Specifically you asked:
“Could you please tell me the frequencies and durations of the door buzzer sounds when doors open and close on the D78 Stock, 1992 Stock, 1996 Stock, and S Stock trains?”.
I can confirm that we hold the information you require.
The table below shoes the duration and frequency of the door buzzers for the stock you have listed (where applicable):
D78 Stock
92 Tube Stock
96 Tube Stock
S Stock
Open
Duration
N/A (retired)
2s
2s
2s
Frequency
N/A (retired)
1900 ±500 Hz
1900 ±500 Hz
660/550 +/- 10 Hz (2 tone)
Close
Duration
N/A (retired)
5s
5s
1.75
Frequency
N/A (retired)
1900 ±500 Hz
1900 ±500 Hz
1500 Hz +/- 100 Hz
The S Stock close chime ceases as door movement commences, whereas on the 92 Tube Stock and 96 Tube Stock the chime continues to door close.
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
