Keeping pace with signalling technology requires investment. Even though passengers may not see it directly, they will experience the benefits in their day-to-day travels.
Thanks to the robust design of technology, there are longstanding signalling systems across rail networks in Australia and New Zealand.
While not ‘broken’, these systems require significant and complex investments of time, cost, and effort to upgrade and remain reliable, despite their age, at a time when investment budgets are shrinking.
However, early adoption and investment is necessary for managing obsolescence and interoperability, across existing networks, jurisdictions, and future infrastructure development.
The signalling evolution
In the mid-19th century, Australian railway signalling relied on basic mechanical systems such as semaphores and hand signals. Due to recurring accidents, semaphore signals were eventually replaced in the early 20th century by mechanical lever frames, which controlled the signals via cables, centralising signalling operation locally and improving safety.
As railway networks grew in complexity, electromechanical signalling systems emerged in the early to mid 20th century, followed by early electronic signalling systems.
These systems leveraged technology advancements and electrical components for remote control and automation, significantly enhancing safety and efficiency.
From the late 20th century to the present, digital communication technologies have enabled the creation of digitalised signalling systems.
Unlike electronic interlockings with limited control distances, digital interlockings rely on Internet Protocol (IP)-based communication, allowing unlimited control distances and more modular system architectures.
This flexibility in system design, combined with real-time monitoring and preventive maintenance, improves system availability and safety across the rail network. The introduction of digital interlocking technology has further enhanced train management and interoperability between different national railway networks, all while increasing network capacity and efficiency.
Ongoing investment for signalling in Australia
Older signalling systems with ageing infrastructure and a shortage of skills and historical knowledge are critical concerns, with some signalling systems that are either outdated or nearing end of life.
Obsolescence management results in increased maintenance costs, lack of spare parts, and potential system failures, while producing risks due to not meeting safety standards.
The team at Siemens Mobility’s Port Melbourne site has dedicated experts to help maintain obsolete equipment – including a 386 computer from the 1980s – to support systems that use older technology.
The limitations of older signalling systems are becoming more apparent as the technology becomes unavailable and the people who have maintained them retire.
Safety is a priority for rail network operators and suppliers. Upgrading to modern systems with higher safety levels can ensure risks such as signal failures, train collisions, and derailments are mitigated.
Rail operators both in Australia and around the world are realising the need and benefits of implementing digital and cloud-based signalling system solutions.
Benefits can include increased capacity and efficiency, reduced costs due to centralising data and operations, adaptability and flexibility for management and optimisation – which is crucial for handling the increasing demands for rail transport. Most importantly, it assists with improving the passenger experience with real-time information that can provide more reliable services.
Siemens Mobility has supported the industry on modernising rail networks worldwide through technologies such as the European Train Control System, Communications-Based Train Control, Distributed Smart Safe System and their latest innovation Signalling X, which the rail technology provider launched at Innotrans in 2024, that can produce significant benefits, potentially raising safety levels even higher and increasing efficiency.
Centralising signalling logic
In recent years, digitalisation has driven the advancements in signalling. By moving signalling infrastructure to the cloud, rail operators can reap benefits, including less network cabling, less equipment and reduced lifecycle costs. There are also innovative opportunities such as combining multiple interlockings into one, or potentially having one interlocking for the entire country.
An instrumental building block for making this transition possible is DS3, which stands for ‘Distributed Safe, Smart System’. It can be run on commercial off-the-shelf hardware, meaning multiple applications can be hosted on the same hardware and software can be updated remotely, providing a lean migration of existing systems.
As far as safety is concerned, rail infrastructure applications on the DS3 platform correspond to Safety Integrity Level four (SIL4), the highest level of safety integrity, while also protecting critical infrastructure from cyber threats (Security Level 3).
Data availability can be secured by geographic redundancies, ensuring that centralised signalling systems remain operational even in the event of location fallouts, hardware failures, or other disruptions.
Rail operations and networks ultimately profit from optimised safety, greater availability, Automatic Train Operation (ATO)-enabled punctuality, and improved total cost of ownership.
An example of nationwide signalling system implementation is in Norway. Siemens Mobility was awarded the country-wide ETCS project for Norway as part of a broader initiative to enhance rail infrastructure.
This involves equipping new and retrofitting existing routes or sections with ETCS-level 2 across the 4,200 kilometres of track and 375 stations in Norway. The project, which will be completed in 2034, aims to increase safety, punctuality, and capacity, allowing for more efficient and reliable train operations.
One of the first lines to benefit from the new technology was the Gjøvik Line North, which began operating with the European Rail Traffic Management System technology in November 2022.
This upgrade is one of the largest digitisation projects in Norway’s railway history and is expected to significantly modernise the country’s rail infrastructure.
Making the move to modernise
As a leading global provider of transportation solutions, Siemens Mobility is at the forefront of developing innovative train signalling systems, bringing the future to customers now.
The solution to mitigating the current risks of older signalling systems and increasing reliability lies in transitioning to more advanced technology, such as digital and cloud-based signalling. The benefits of such an upgrade would be vast, offering opportunities to improve system performance, reduce costs, improve compliance with evolving industry standards and enhance operational flexibility.
The evolution of rail signalling technology presents critical opportunities for Australia and New Zealand to modernise the rail networks. By investing in signalling systems and moving towards more advanced technological solutions, rail operators can future-proof rail networks and improve reliability and efficiency, providing maximised network capacity and system availability of up to 100 per cent across the entire rail network.
The National Rail Action Plan (NRAP) supports this focus on interoperability and digital signalling, aiming to create a unified and efficient rail system across the nation.
To support this investment, the network infrastructure to support the digitalisation of the rail industry needs to be implemented.
As an industry, Australia and New Zealand have embarked on the journey to modernise railway signalling, taking inspiration and lessons from international projects like Norway’s nationwide digital signalling project. Continued and ongoing investment is crucial. Even if passengers may not immediately notice the changes, stakeholders across the rail network will reap the benefits of advanced signalling technology that will ultimately improve system performance, reliability, and operational efficiency.
