Alstom has opened a new, state-of-the-art bogie overhaul workshop at the Metro Trains Sydney (MTS) facility in Tallawong, New South Wales.

The specialised workshop will play a central role in the network’s 1.2 million-kilometre train overhaul program, which is the first major heavy overhaul milestone for Sydney Metro’s fleet of automated trains.

At the Tallawong workshop, Alstom will carry out precision maintenance and upgrades to improve the reliability, resilience and long-term performance of trains on the M1 Line.

A bogie is the wheeled assembly that supports and guides a rail vehicle, and each one is fundamental to the ride quality, safety and performance.

Each of the driverless Sydney Metro trains has 12 bogies per standard six-car trainset. These are a mix of motorised and non-motorised bogies.

“Bogies are the key sub system of any metro train,” explained Sanjeev Saini, Maintenance Project Manager at Alstom.

The metro train runs on specialised bogies – the wheel assemblies beneath each carriage that ensure smooth movement, stability, and safe braking as the train travels along the track.

Much like a car, the wheels of a train have a life cycle. Train wheels experience gradual wear from prolonged interaction with rails, leading to a reduction in diameter. This wear is tracked against the condemning limit, a predefined safety benchmark typically reached after approximately 1.2 million kilometres of operation.

The original 22 Sydney Metro trainsets, which were introduced in 2019, are now approaching this threshold.

“Many of them are now around the 900,000-kilometre mark,” Saini added.

“At the new workshop, two different types of maintenance will be performed – planned maintenance, and corrective maintenance.

“The bogie overhaul program falls under planned maintenance.”

Overhauls carried out at the new facility will include the full disassembly, inspection and recertification of bogies, as well as the rebuilding and testing of traction motors, gearboxes, brakes and wheelsets.

Worn components such as bearings, seals and rubber elements will also be replaced before rigorous testing and return to service.

The first overhaul will start in June, and operations will gradually ramp up.

“With any maintenance operation, there is a learning curve,” said Saini. “The first overhaul will take about two months, and from there we will reduce the time for this work to four weeks per overhaul.

“Given we are both the manufacturer and maintainer of the fleet, Alstom can translate our knowledge of the trains into strong maintenance outcomes.

“This is delivered in close partnership with our operator, MTS, and delivery partners, working as one team with a shared focus on performance and passenger outcomes. That’s a real advantage for customers: having a partner that both builds and maintains the fleet.”

Saini said Alstom has invested in an array of top-of-the-range equipment from around the world for the new site, in addition to raised tracks, weighing systems, test benches, and a dedicated bogie wash plant.

“Our GEMINIS wheel borer, which performs wheel boring to within thousands of a millimetre, has come from Spain, and our MAE wheel press is from Germany,” he shared. “Our gearbox test bench came over from China. We have world class machinery right here in Sydney – it’s a unique resource. Our state-of-the-art international machines are all sitting together in the same workshop, and all of them are critical to the efficiency of the operation.”

A workshop already existed on-site, but has been expanded and reconfigured to deliver a major uplift for the Sydney Metro maintenance program, strengthening and future proofing New South Wales’ overall rail capability.

“Alstom’s maintenance contract for these metro trains started in 2019, and the COVID-19 pandemic put a lot of pressure on the supply chain,” Saini highlighted.

“We were waiting for parts coming from overseas, and even locally. To avoid delays like this in the future we came up with a plan to minimise disruption. We began exploring the idea of developing capability in-house, which had the added advantage of generating local jobs, strengthening the local Australian supply chain and dramatically reducing turnaround times for overhauls.

“This is the Alstom model; one that’s different to other market players. We invest, we localise, we are here for the long term.” The workshop was delivered using a host of designers, contractors and suppliers based in New South Wales. Martinus Rail was the principal contractor for the major civil works, with Moxon, Trakblaze and Samtech supplying specialist systems including rail installation, weighing infrastructure and raised track and turntable assemblies.

The build phase created 15-20 local jobs, and the workshop will support an initial team of 20 roles, with capacity to expand this in the future.

The workshop brings whole-of-network benefits by building a highly skilled local workforce with deep expertise across bogie systems, creating transferable capability for future fleet and infrastructure projects.

It has also created exciting opportunities for young professionals such as Tom Frost, a Graduate Maintenance Engineer, who started working with Alstom as an intern three years ago.

“Alstom gave me my start in the railway industry, and my interest has really grown from there,” Frost said.

“It’s very positive when you can give something as powerful as a new Metro line to the community.”

Frost’s role is mainly focused on process engineering.

“With so many new machines coming to the workshop from overseas, the knowledge the Original Equipment Manufacturers (OEMs) have to transfer to us is key,” said Frost. “I am helping to manage that transition.”

He has really enjoyed learning about the practical and theoretical components of the equipment.

“Our team is more than happy to pull things apart and figure out issues,” he said. “I have learned so much and really built up my engineering confidence.”

Steven Jones, Head of Rolling Stock and Communications-Based Train Control (CBTC) at Metro Trains Sydney, said MTS is proud of the project’s support for the local economy.

“It’s great to be able to provide local jobs,” he said.

“We were the first Metro GoA4 (Grade of Automation 4 – the highest level of automated train control) network in Australia, and as this network expands, we’re supporting in-house capabilities and developing skills for the future.

“We’re not relying on offshore capability or a volatile job market.”

Jones said the new workshop has come at the perfect time, as Sydney Metro gears up for the opening of the Southwest extension later in 2026.

“As the fleet is getting older and the kilometres travelled are ramping up, we’ve got to make sure that the bogie condition and overhaul process doesn’t affect asset availability.

“We’re currently running a shorter network. With this workshop, we’ve got a lot more flexibility and control, so we can maximise fleet availability. If there were to be an incident on the network or a problem with an asset, we have the capability to move our maintenance programs or bring in trains ad-hoc. This workshop is going to be massive for us.”

He added that passengers will see the knock-on benefits of this additional capability.

The workshop isn’t just for bogies – there’s the potential to do other maintenance too.

Alstom is already working with Sydney Light Rail, another Alstom manufactured and maintained fleet, with brake overhaul confirmed to occur onsite. Over time, the workshop will be able to support other rolling stock owners and maintainers requiring bogie system or subsystem overhaul, subject to approvals from MTS.

“This was the first driverless Metro in Sydney, but will not be the last,” Saini added.