13-11-2012, 12:43 PM
I would like to suggest a clarification. RA is defined as Route Available and not Right Away. Much of the above discussion is based on process which falls outside of the signalling system.
Platform staff and guards/conductors still use flags/lamps to communicate where the staff are available. There are many restrictions about how a train must be dispatched (read the Kings Cross incident on RAIB which describes the process and the failings in that instance). As PJw stated, the RA indication is interlocked with a proceed aspect. That doesn't detract that the platform staff and guard cannot try to dispatch a train without ensuring the signal is off.
Platform staff and guards/conductors still use flags/lamps to communicate where the staff are available. There are many restrictions about how a train must be dispatched (read the Kings Cross incident on RAIB which describes the process and the failings in that instance). As PJw stated, the RA indication is interlocked with a proceed aspect. That doesn't detract that the platform staff and guard cannot try to dispatch a train without ensuring the signal is off.
Le coureur