CNFiTech worked with Rockwell Automation to design and build an advanced system to protect facility staff and equipment at NSW's new train maintenance facility
From 2024, commuters on sections of regional New South Wales began travelling on a state-of-the-art fleet of intercity trains. Named after the Dharug word for emu, the 610 carriages in the Mariyung fleet offer modern safety and advanced features for customers who make almost 45 million journeys a year on this network.
To support these critical assets, Transport for NSW (TfNSW) constructed a 500,000m2 depot at Kangy Angy near the Central Coast. The TfNSW Intercity Fleet Maintenance Facility, which runs 24/7, has about 6km of electric rail lines and heavy equipment such as a 50-tonne wheel lathe.
One of the core requirements for the facility was to implement a robust safety system, and CNFiTech was tasked with developing a flexible and functional design for a Depot Personnel Protection System (DPPS). The system had to be SIL-2 rated, designed with readily available proprietary safety hardware and software tools, and easy to maintain. SIL, or Safety Integrity Level, is a rating system that associates safety with the numerical probabilities of hazardous failures (0 being the lowest and 4 being the highest) for continuously operating systems or on-demand systems.
As a well-established specialist electrical and systems engineering company, CNFiTech drew on its experience gained over 25 years to design, manufacture, and implement a suitable solution for TfNSW.
CNFiTech is an engineering services specialist in the fields of automation, electrical engineering, and systems engineering, and it is a Rockwell Automation System Integrator partner with extensive experience with Rockwell Automation hardware and software.
"The system for TfNSW is designed to protect facility staff and equipment by delivering the safe and controlled movement of rolling stock into and out of the train maintenance depot," explains Aafiah Khan, territory manager, NSW, for Rockwell Automation.
To deliver this project, CNFiTech adopted the Authorised Engineering Organisation (AEO) framework that provided TfNSW with confidence in the capability of the company to deliver fit-for-purpose assets.
Constructability of design
The DPPS has been designed to interface with the automated derailment monitoring system. It also ensures the safe movement of trains into and out of the maintenance facility building and a lock-out personnel system prevents staff from accessing the area above the trains while the traction system is energised. Constructability of design is one of CNFiTech's core skillsets – an ability that was highly valued by TfNSW for this project.
Underpinning this integrated safety system is Rockwell Automation's GuardLogix® platform combined with associated safety devices, safety stack lights, and fortress keys and locks. The Rockwell GuardLogix safety system hardware is rated for up to SIL-3 system implementation.
"GuardLogix combines standard control functions with safety functions in a single controller platform," said Khan. "This integration helps streamline the design, programming, and operation of industrial systems while maintaining a high level of safety."
CNFiTech completed an assessment of the DPPS at Kangy Angy and derived several SIL functions comprising SIL-0, SIL-1, and SIL-2. This resulted in a clear definition and agreement with TfNSW of the system safety classification. As an added benefit, much of the work done by CNFiTech at the DPPS can be redeployed to other rail maintenance facilities.
CNFiTech rail and automation manager, Joe Dwyer, said, "Implementing Rockwell Automation's GuardLogix platform meant that we could confidently deliver the required level of safety and control to TfNSW. Protection of personnel was a key deliverable of this project, and Rockwell Automation's hardware was able to deliver optimum ongoing performance."
Checking that equipment is in a safe state
The integrated safety system monitors and interlocks the various sub-systems in the correct states for safe working through a combination of trapped key and electronic safety interlocks. Equipment may be controlled and operated by manual or automatic mechanisms. The safety system independently checks that the equipment is in a safe state and ensures it is disabled with an automatic or semi-automatic (monitored trapped key) interface.
"The safety ethos has been embedded throughout the facility right from depot doors, overhead platform access, retractable overhead wiring, train lift systems, and bogie turntables on designated roads," said Dwyer.
The solution implemented will help with the safe movement of trains into and out of the maintenance depot and support the safe working of maintenance staff on trains at the facility.
"The deployment of Rockwell's GuardLogix integrated programmable electronic safety system helped us achieve efficient operation of the maintenance depot," concluded Dwyer.
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