edwin_m wrote:A semaphore main stop signal when clear indicates that the train can proceed as far as the next main stop signal, which in your case would be the Advanced Starter. However it probably wouldn't be cleared until the train stopped in the platform, in case the driver forgot there was another signal (and that his train was terminating!) and started accelerating away.
Madscientist wrote:Thanks. ( there's two threads on this ) , I always thought that semaphores were cleared in reverse order, " unless " rule 39 A was being . Because anything else could show clear to a driver yet find that a further stop signal was not clear.
This reverse order is clearly the case for distant a, a distant cannot be cleared until ALL stop signals ahead are clear , clearly that is reverse order
I understand your comments re using running signals for shunting movements seems reasonable
In my specific case the platform starter had a disc under it. Are you saying the disc would ONLY. Be used to signal an secondary movemrent , ( there was a head shunt siding immediately after the points to connect platform 1 to the main line , which was typically signalled by the running signal normally ) , would the disc not be used instead of the starter to indicate ANY movement forward instead of using the starter or just into the head shunt
Wilkinstown wrote:The main reason for clearing semaphore signals in the opposite direction to an approaching train would be to minimise movement by the signaller - advance starter, starter, home, outer home and distanct would typically be operated by levers placed one after the other or at least one left/right of the other in the frame. If you don' do it this way you have go back to clear the distant !
Sequential interlocking would not normally (or ever ?) allow signals to be cleared in the manner described above.
Hi Madscientist.Madscientist wrote: " .... As I understand it, and yes that may be faulty , this isn't a sequential locking issue, as that is primarily to ensure that signals are replaced to normal , before the sequence can be started again. .... "
StevieG wrote:I just thought it worth making clear that sequential locking is only about enforcing the sequence of clearing stop signals at the time of attempting to clear them, and has no bearing on any sequence of replacing them to Danger, as, in case of emergency, it normally ought to be possible to place any main running stop signal to Danger at any time, irrespective of the position of other stop signal levers reversed for the same train.
Would you care to re-examine your "...wrote:" 'quotes' Mike? : I'm unclear on which comment/s or part/s thereof that your point is meant to be relevant to.Mike Hodgson wrote:StevieG wrote:Madscientist wrote:I just thought it worth making clear that sequential locking is only about enforcing the sequence of clearing stop signals at the time of attempting to clear them, and has no bearing on any sequence of replacing them to Danger, as, in case of emergency, it normally ought to be possible to place any main running stop signal to Danger at any time, irrespective of the position of other stop signal levers reversed for the same train.]
The sequence of clearing signals may not be laid down by the rules, but putting them back is. You should put each signal back as soon as the train has completely passed it, with a proviso about waiting till it has passed any junction points. So they would be put back sequentially. And if you have omitted to restore the Distant to Caution, the locking will prevent you putting back stop signals should you need to do so in emergency.
Users browsing this forum: Google [Bot] and 4 guests