"Clive" wrote in message
...
In message , asdf
writes
One would hope that such a safety critical feature is tested on a regular
basis, rather than it taking a SPAD for anyone to notice there is
something wrong.
They used to be tested on every trip both northbound and southbound, like
Leicester Sq. Is this no longer done?

A "tripcock tester" only tests that there is a tripcock arm present and in
correct alignment (at which point the tripcock tester light goes out). It
does NOT check that the tripcock will stop the train if activated, the
assumption being that if it is in the right place and alignment that it will
do the job it is provided for, if required.