Among the eight distinct crews destined to operate the Melbourne Suburban Rail Loop’s massive tunnel boring machines (TBMs) excavating the southern section of tunnels between Cheltenham and Glen Waverley, one team will carve out a distinct piece of Australian engineering history: it will be composed entirely of women.
While it would be easy to lean into sensationalised headlines, the operational reality of setting up such a crew requires confronting a stark mathematical truth rather than an attitudinal one.
Australia needs more skilled engineers and construction professionals to deliver an ambitious infrastructure pipeline. That’s not going to happen if we ignore more than half of the population.
When the concept of an all-female TBM crew was pitched to engineering delivery lead Isolde Piet, her initial reaction was completely pragmatic.
“It was going to be difficult,” Piet recalls saying, “with the limited number of women that are in the industry, but also, I think, limited opportunities to get into the industry if you don’t have experience.”
The project committed to building its own pool of female tunnellers from scratch. Recruitment campaigns kicking off in 2024 yielded a staggering 900 applications. By mid-2026, 18 women were already active onsite, with plans to scale the cohort to more than 30 over time.
The training pipeline relies heavily on an open-minded collaborative culture onsite. Piet gives immense credit to her tunnelling general superintendent Steve Teraki for setting the tone.
“He was very much open to giving it a go. He’s been a great support in recruiting the right people with the right attitudes, because that’s what it is. You don’t necessarily need to have the experience, but he’s looked at: What’s your appetite? What’s your attitude towards the work?”
Then the training begins.
The comprehensive pathway uses a Certificate III in Civil Construction paired alongside an immersive, on-the-job training model. It’s a rigorous framework designed to onboard workers who have never set foot on a construction site, teaching them what good safety and processes look like.
Because of this heavy structural runway, Piet confidently dismisses any cynicism or accusations of tokenism.
“I think that the amount of effort that we’re putting in – plus the pathways we’ve created through training in the Victorian Tunnelling Centre, early onboarding, training on the job – there’s so much serious time and effort already gone into it. I would say it proves it’s not a token exercise. The industry simply needs more skilled workers.
The gender of this crew is not the most interesting variable.
“The interesting part is the model: that major public infrastructure projects can function as training grounds, expanding the workforce and offering a way into the industry for those who never before saw a path.”
As Australia battles its most profound contemporary engineering skills shortage – a 2022 report by Engineers Australia warned that women occupy a mere 13 per cent of the domestic engineering workforce – the SRL East project stands as a practical template for workforce expansion.
And in recognition of the importance of retaining female engineers, a new Engineers Australia report published earlier this month outlined that 13,000 more women would be in direct engineering roles, if employed at same rate as men.
I just see people
Piet has spent a highly decorated career frequently operating as the only woman in demanding professional environments, giving her a grounded, deeply humanistic worldview on the gender divide.
“Ultimately I don’t feel like the odd one out. Others are probably the ones who have to deal with another character in the room as opposed to me,” she said. “I just see myself more as another person in that room … I see people, I don’t see male or female.”
Piet’s ultimate goal is to shift the goalposts until a headline like this is deemed entirely unremarkable – to make it as unlikely a headline as “all-male tunnelling crew”.
“Hopefully what shifts is that it becomes more normal, that it doesn’t become a thing,” she said. “You throw a rock in the water and you get this ripple effect. So by just throwing a rock in the water, then automatically there’ll be more women that, in turn, attract more women – and not because they’re female, but just because they’re interested and they meet someone. They’re triggered by their job and might just end up in the same industry.”
A global trajectory
It was an international study trip to Japan during her third year at university that steered Piet’s career path underground. Witnessing a massive tunnel boring operation exposed her to a multi-disciplinary environment requiring geotechnical, structural, mechanical and logistical engineering to function in perfect harmony. She was hooked.
“Underground construction today is an official specialty, whereas at the time it was a combination of things you had to do. So I went back, I spoke to a few professors to shuffle my topics around, and that’s where it started.”
Her breakout professional role placed her on the high-speed rail link connecting Amsterdam and Paris.
“It used a massive TBM spanning nearly 15 m in diameter. Serving as a junior engineer alongside an international contractor offered me incredible multidisciplinary professional exposure.”
“It was very much at the start of the project, which means you basically get to work through the very first steps of getting a project set up, getting the team established onsite,” Piet said. “I was able to actually transition through quite a few different roles at a time as well, which was very interesting to do.”
Following her work in Europe, Piet migrated to Australia in 2007, to jump straight into the early stages of Brisbane’s landmark Clem 7 tunnel project. Her career subsequently took her to Turkey to oversee complex urban road and rail tunnelling programs. However, when escalating political instability saw tear gas drifting through her young children’s bedroom windows, she and her partner – also an engineer – made the choice to relocate to Melbourne.
When the Suburban Rail Loop Authority began assembling its initial team, Piet jumped at the chance to join the tender process. It offered a rare opportunity to influence a mega-project from its absolute infancy.
“I’ve always been on projects that were already started, SRL was a chance to be involved in every stage. That whole trajectory from day one.”
Geotechnical realities
Piet’s core specialisation – soft-ground TBM tunnelling – is a rare skillset in the Australian civil engineering landscape. While domestic infrastructure pipelines have spent twenty years boring through hard rock expanses from Brisbane to Sydney, urban soft-ground geology requires a radically different engineering playbook.
“Rock mechanics was something I had zero exposure to in university,” Piet pointed out. “In the Netherlands, there’s simply no rock to tunnel through, which is very different to Australian geology.”
Changing the way people live
The Suburban Rail Loop represents a massive transformation for Melbourne’s transit grid, decentralising a historically radial system. The 26 km SRL East line between Cheltenham and Box Hill is the first section in the multi-decade project.
The sheer engineering scale of the build is immense:
- Eight TBMs: Four sourced from Herrenknecht and four via China Railway Engineering Group
- Depth: Reaching up to 60 m below the surface at their lowest clearance points
- Workforce: More than 3300 personnel working on the SRL East project
For Piet, the ultimate value of this subterranean work isn’t found in the hidden structural geometry of the concrete rings, but in the legacy left behind.
“You build something for generations to come,” she said. “It’s not so much just infrastructure – it’s about changing the way you live.”
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