They are set to allow the passage of trains as well as the standard light signals for mainline movements.
Although used primarily as a safety device to regulate the passage of trains, it was also used to pass messages between the staff.
Many bridge builders, and the general public, did not believe a suspension bridge could allow the safe passage of trains.
Operators also record the passage of trains by their station.
Two tracks are normally reserved for the through passage of express trains.
Engineers had blasted a tunnel for the passage of trains.
This permits signals to operate automatically with the passage of trains, enforcing the distance between them.
The station also has a head shunt to permit the passage of express trains.
The structural behavior of a composite bridge during the passage of high-speed trains.
Bridges had to be built, corduroy roads made for the passage of trains.