the abandoned stations web site is one of my regular calls on the web, there is also this one 28 days which though I dont nessesarily agree with their methods do sometimes get good photos.
there is also subterranea Britannica which can have some good reports / photos
hope you enjoy.
steve
editted because I cannot spell
I love the fact these fans are so powerful they can move back and forwards in time
caption from http://mark5810.foto.../p63221261.html 1) JZA, NLU 93465 @ Manchester Piccadilly on 7th October 2010, this is a fan wagon for use in tunnels
Steve