This sign looks like Johnston font to me, even though the Thames Barrier
is owned by the Environment Agency, not TfL. Was it ever TfL owned?

https://youtu.be/0ImibAisXN0?t=3389

Mr Wiki he say...

"The barrier was originally commissioned by the Greater London Council
under the guidance of Ray Horner. After the 1986 abolition of the GLC it
was operated successively by Thames Water Authority and then the
National Rivers Authority until April 1996 when it passed to the
Environment Agency."


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Basil Jet recently enjoyed listening to
1975 - Down By The Jetty - Dr. Feelgood