Can an interlocking signal have more than one head showing other than stop or red at one time? In other words could a two headed signal that protects the entrance to a siding or protects a junction show a yellow over yellow or yellow over green if it is a signal distant to another interlocking signal. On the Norfolk Southern in CTC territory the engineer will receive a yellow over green from the signal distant to a signal that protects a siding or diverging route, which would have a red over yellow or red over green. What I’ve wondered is if you have a long siding with a set of crossovers in the middle and the dispatcher wants a train to stay on the main track but crossover in the middle of the siding would the signal which protects the entrance to the siding display just a yellow over red or would it show a yellow over green indicating the next signal would be a red over green or a red over yellow?
Long question, short answer: yes.