By Edmund Ang, Associate Director – Fire & Risk, AECOM Technical Lead for Sydney Northwest Metro Fire and Life Safety Certification

Sydney Northwest Metro was Australia’s biggest public transport infrastructure project and the country’s first fully automated train system. It is also the first time driverless metro trains have been integrated with an existing driver-controlled rail system along a shared corridor.

This presented some unique fire-safety challenges in the design and planning stage to ensure that both modes could operate safely together while sharing stations and the broader rail corridor.

Solving this challenge allowed the existing Epping to Chatswood Rail Link to be upgraded to metro standards, providing customers with seamless transfers between the metro and suburban rail services at Epping and Chatswood Stations.

The challenge

The new metro trains are fully automated, whereas the existing Sydney Trains are entirely driver operated. Due to the different operating systems and related safety protocols, the two modes are required to meet two different legislative regimes, which presented a unique engineering and regulatory-compliance challenge.

In relation to operating safely, Sydney Metro and Sydney Trains are two entirely different operators, with their own safety protocols and procedures. As a result, each operator required separate approvals under the Rail National Safety Law. However, from a customer’s perspective, when someone switches between a metro service to a Sydney Trains service at Epping or Chatswood Stations they want it to be as seamless as possible, which is consistent with Transport for NSW’s customer focus objective of ensuring an easy and connected service.

A seamless transition is important from a customer’s perspective, but also from a safety perspective. If an incident occurs in the shared network, it requires a unified response despite the operators having their own protocols.

AECOM’s challenge was to integrate the fire-safety management of each operator in these shared stations, and demonstrate to the regulators, including the Office of the National Rail Safety Regulator, that these shared areas are safe for operation. In addition to detailed stakeholder engagement, workshops, and diligently documenting the various requirements, we adopted advanced computer models to simulate the conditions in a station for a fire, even factoring in the influence of wind (something which many passengers have felt transiting through an open station).

Outcomes achieved

AECOM developed a new process to ensure legislative approvals were achieved, while considering the requirements of both operators and the associated legacy and new infrastructure and operating protocols. This was a complex undertaking because this was the first time a certification project of this nature and complexity had been attempted in the Australian rail industry.

A new set of protocols had to be co-designed to agree how to manage key stakeholders such as emergency services, council, Sydney Metro and Sydney Trains. Any decision made by one operator had to consider the impacts on the other. No decision around safety or fire could be taken in isolation, as there was always likely to be an impact on the other operator or station users.

Sydney Metro introduced several new safety protocols, including passenger screen doors at all stations, something which do not exist on the Sydney Trains network. This project essentially enabled a new framework that can integrate new safety technologies and protocols with existing asset and operation protocols and provide certification to verify that the integration meets the safety benchmark.  This framework will enable a similar integration for future Metro projects where existing rail infrastructure will be shared by the new metro trains.

A segregation fence was erected along the shared corridor between Epping and Chatswood stations to minimise the risk of passengers or workers from one service accidentally crossing onto the other operator’s tracks. In addition, AECOM developed an overall fire safety management strategy between the two operators to ensure a fire incident within the shared corridor can be seamlessly managed between the two operators. The strategy involved communication protocols, advanced onboard detection systems and training exercises.

The operations of Sydney Trains and Sydney Metro brought a new definition to integrated infrastructure. When two operators are using the same station, conventional thinking suggests each operator should maintain their own fire-safety systems (e.g. fire alarms, emergency broadcast system, water sprinkler system, emergency lighting, mechanical smoke control system and CCTV), linked together via a common interface. In practice, this presents significant engineering challenges as both operators have different hardware and protocols, and two separate systems also increase the system’s complexity, resulting in a greater risk of system malfunction.

Instead, AECOM co-developed an engineering strategy to share the stations’ existing fire-safety systems between the operators, and enhance the system where necessary. To respect the operators’ need to have certain fire safety-related communication systems operating independently, AECOM developed the segregation strategy for Epping Station to ensure these systems (i.e. the train-monitoring system, remote public-address system, critical-equipment monitoring and reporting system and station security and locking system) can function independently, as required by the operator, yet can retain an overall interface for the whole station.

This approach allowed the majority of the fire-safety systems to be re-used, and provided a simpler system as there is less doubling up, and fewer operations and maintenance complexities to consider.

The AECOM team first started on the project in 2015, and the completion report that provided fire and life safety certification for Sydney Northwest Metro and Epping Chatswood Rail Line Shared Areas certification was finished in time for the opening in May 2019.