06-08-2014, 08:29 AM
I am aware that for a signal with a TPWS TSS (or ATP I believe) there can be "self reversion" problems if the joint is closer than 5.5m from the signal. If the joint has to be closer than this we put Delayed replacement - "last wheel or second track" (which is $40 on the first track on control tables).
Self reversion is when the train occupies the 1st track circuit, replaces the signal to red and THEN travels over the (now energised) TPWS, which therefore acts as if it were a SPAD and stops the train.
If your GPL has TPWS then delayed replacement would be applied. If it does not, ... Not sure. I can think of cases where delayed replacement has been applied anyway but I think it would not be a requirement.
Self reversion is when the train occupies the 1st track circuit, replaces the signal to red and THEN travels over the (now energised) TPWS, which therefore acts as if it were a SPAD and stops the train.
If your GPL has TPWS then delayed replacement would be applied. If it does not, ... Not sure. I can think of cases where delayed replacement has been applied anyway but I think it would not be a requirement.