High Capacity Signalling

Perth’s urban rail network currently uses an Automatic Train Protection (ATP) system to maintain safe speeds and distance between trains. The existing ATP system is approaching its end-of-life and needs to be replaced.

The existing ATP system uses a fixed block signalling system essentially dividing the metropolitan rail network into fixed block sections. Coloured signals are used at the start of each fixed block section, maintaining a number of blocks between trains for safe operations which means more space between trains and therefore limits the number of trains on the line.

The new ATC system being delivered by the HCS Project uses Communications-Based Train Control (CBTC) technology which is a moving block signalling system that relies on real-time train information rather than fixed signals. Moving block signalling systems allow safe separation between trains based on real-time information on train speed, distance and location. This safe separation considers the braking capacity of the train, the slope and geometry of the track, and speed, time and distance between trains.

The system creates a protective bubble or block which moves with the trains along the line, with only one train allowed in the bubble and no overlapping of bubbles. By managing train speeds, the system can manage braking distances so trains can always safely stop within their exclusive bubble.

For more information on the moving block system, view the ONRSR Safety Message.

Once operational, the Communications-Based Train Control (CBTC) signalling system will allow each train on the network to continuously send real-time data on the train’s speed and location to central signalling interlocking at the Public Transport Operations Control Centre – the system’s ‘brain’. The train also interacts with passive information plates on the track to confirm its location and speed with onboard systems.

This enables the Operations Control Centre to monitor the speed and location of every train on the system, giving much clearer and more accurate positioning of each train relative to the ground and to each other.

The trains can move on to the next location and change speed only after automated permission is given from the control centre. If at any time the network loses contact with a train, automatic safety controls will halt the train until contact is re-established.

The ‘moving block’ system allows trains to safely run closer together – using 30 or 40 per cent less space than the existing system -- with an assurance that there is sufficient space and time to adjust speed or safely stop in any circumstance.

The new Automatic Train Control (ATC) system will be delivered in stages to minimise disruption to train operations, with supporting infrastructure currently being rolled out at stations and across the metropolitan rail network.

Due to the need to upgrade the rail network in stages, the HCS Project is expected to take approximately eight years to complete. This estimate is based on similar projects undertaken around the world.