Next-generation High Capacity Signalling technology will be installed on the Metro Tunnel and on the Cranbourne, Pakenham and Sunbury lines to deliver more trains, more often during peak times.

The technology will also be rolled out on the new Melbourne Airport Rail when it is built.

These upgrades will revolutionise Melbourne’s train network as we move towards a reliable ‘turn-up-and-go’ network, similar to those in London, Singapore or Hong Kong.

The bigger, more modern trains running on this new network will provide capacity for 121,000 passengers every week on the Cranbourne and Pakenham lines during peak periods – that’s 45% more peak capacity.

Existing signals used along these lines will be also be updated so trains that use High Capacity Signalling and those that use conventional signalling – such as freight and regional passenger services – can safely and efficiently operate on the one system.

Moving block signalling

High Capacity Signalling is the hi-tech 'moving block' signalling system used around the world that enables trains to automatically adjust their speed to maintain a safe distance from the train in front.

The new technology will replace Melbourne's current 'fixed block' system, which uses coloured signals to indicate when it is safe for a train to proceed.

We are currently testing High Capacity Signalling on a section of the Mernda Line between Epping and South Morang stations. Following this trial the technology will be rolled out in the Metro Tunnel and along the new Sunbury to Cranbourne/Pakenham line. It will be the first rollout of High Capacity Signalling on an existing network anywhere in Australia.

Diagram showing the difference between fixed-block and moving-block signalling

How it works

To visualise how High Capacity Signalling works, imagine driving on a freeway. Adaptive cruise control adjusts the vehicle speed according to the distance from the car ahead, to help the driver travel more safely.

Under the control of train drivers, High Capacity Signalling works in a similar way by communicating this information wirelessly between trains, the railway line and the signal control centres.