East of there, lineside towers control the various switches and signals under the direction of the dispatchers in Jamaica.
During the first year of the railway, a signal box was created to help control the points and signals around the station area.
The station also had a signal box that the controlled the points and signals in the station and further down the line.
Train dispatchers cannot directly control intermediate signals and so are almost always excluded from the dispatcher's control display except as an inert reference.
It was later expanded in function to control points and signals for other stations in the inner Melbourne area.
An eight-lever LNWR ground frame controlled the points, signals and level crossing.
The second floor contains the tower's interlocking machine, used to control signals and switches.
This bidirectional channel transfers control signals between source and destination in addition to the clock and streaming video data.
The system would also control signals along secondary routes, for maximum flow.
The boxes containing the electrical relays that control signals were specially locked to prevent tampering.