In effect you are right, the signaller will know when a train has left
the affected section and be able to authorise a train to pass the
affected signal BUT not over the train radio, BUT when passing a signal
failure red the train will then be stuck doing "a speed at which you can
stop short of any obstruction" in other words the train will be doing
under 10 mph (if you try to exceed 10mph the brakes will come on), 5mph
or less is more likely (There's an alert noise if you go over 7mph,
doing 5mph keeps the cab noise down!) this is for 2 correctly working
signals, if the next one is also failing (not uncommon) then the whole
process has to be started again.

That is why 1 signal failure can FUBAR the whole Met, Hot & Cold, &
Circle line.



Boltar wrote:
Here we go again, the whole clockwise section of the Circle &
H&C line was buggered up because of a single signal failure.
Just how hard is it to cope with a light stuck on red? Train gets
to signal , line controller gives clear if ok to move , train
moves across signal, resets , continues on journey. This isn't
bloody rocket science so can someone explain why LU goes to hell
in a handbasket as soon as something like this happens?? Its not
like it hasn't been happening for the last 120 years which to me
seems like a reasonable amount of time to sort out a practical
solution which doesn't involve trains going nowhere for 15 bloody
minutes. FFS , just how complex a procedure is it?

B2003