07-03-2010, 05:42 PM
nagaraju_dw,
To the best of my knowledge for approach control, we use delta tracks (or position detectors or track circuits) to start a timing relay (JR) which proves the speed of the approaching train is appropriate when only a restricted overlap is available at the following signal. If the test is passed a timing stick relay (JSR) is energised. The JSR is then included in the signal relay (GR) circuit. The delta relay and JR are down proven in the previous signal's selection.
Alasdair
To the best of my knowledge for approach control, we use delta tracks (or position detectors or track circuits) to start a timing relay (JR) which proves the speed of the approaching train is appropriate when only a restricted overlap is available at the following signal. If the test is passed a timing stick relay (JSR) is energised. The JSR is then included in the signal relay (GR) circuit. The delta relay and JR are down proven in the previous signal's selection.
Alasdair