Yesterday, two members of staff from the London Transport Museum and I visited Clapham South Deep Shelter, London, with one of the Windrush men who stayed there in June 1948. It was his first visit since then; he remembered the time there, and the historic occasion. The Shelter is one layer below the Northern Line, and we hear two trains (in opposite directions) passing over our heads every minute. 

More info to follow. 

Arthur