(04-07-2011, 09:32 PM)PJW Wrote: He means "Out Of Correspondence" i.e. if the interlocking request is for the points to move to normal then the alarm is given (after a suitable delay) if the points don't achieve normal or indeed if normal detection is later lost unexpectedly whilst the points are supposed to be staying normal.

In your description of the incident it is not immediately obvious what alarm was given- at first reading I thought that the points had moved under the train or indeed the train had trailed through them because they were in the incorrect lie and thus an OOC alarm would have seemed likely, but that is not my understanding of what happened. I believe that the 2nd train never received a proceed aspect and what the signaller observed was the route seemed to set itself but then was cancelled shortly later due to the movement of the 1st train

(04-07-2011, 08:47 PM)onestrangeday Wrote: hi jerry:

sorry for my poor understanding, what is OOC alarm, or do you mean OCC ?

(04-07-2011, 08:54 AM)Jerry1237 Wrote: As for the points "failure" alarm, was it actually an OOC alarm? There needs to be care taken during design to avoid cyclic locking or to get locking/trains into Mexican standoff situations. With the ever larger and more complex layouts we are expected to deal with, the chances are these situations are far more likely to occur.

PJW,

There are now many depots that are fully signalled throughout. Temple Mills is one (which that screen layout isn't).

Jerry