Arrived at Clapham Junction around 6:30 yesterday evening to be
greeted by a horrendous ear-piercing alarm and the curious sight of
lots of passengers with fingers buried deeply in ears. Most platform
staff were presumably sheltering somewhere from the noise, which
wasn't exactly reassuring to people arriving on trains and who
wouldn't have a clue if the alarm was genuine or not. Once a member of
staff was found the only advice given was to not panic and for
passengers to just cover their ears!

The situation wasn't helped by a failure of the CIS displays, which
temporarily gave up showing actual train departures and instead
instructed commuters to "listen for announcements", which was all but
impossible.

Apparently it took over 3 hours before an engineer arrived and found
the off switch. I do wonder what would have happened if there had been
a genuine fire/security alert during that time, given that it was
impossible to hear and tannoy announcements

Someone uploaded a video of the situation to YouTube -turn up the
volume to get the full effect...
http://www.youtube.com/watch?v=UAuW2IbnGGE

~cj