A Milestone on the Sydney Metro-Western Sydney Airport line

At the bottom of a 21-metre-deep station box, scores of workers have begun pouring concrete for the base of the St Marys station that will rise above it.

One of six that will dot the new Sydney Metro-Western Sydney Airport line, it will serve as an interchange, connecting the new airport under development to the west of the city’s Central Business District (CBD) with the rest of the rail network of Sydney, which is also expanding in other directions to accommodate the needs of a growing population.

The drums of mixer trucks rotated and groaned as the workers directed the flow of concrete during a recent pour across 52 square metres of formwork, the temporary structures installed to support the concrete until it hardens across the station box, which measures 350 metres in length and 22 metres in width. The hundreds of cubic metres of concrete will cover 156 piles already driven into the ground to support the floor, known as the base slab. The installation of some 14,500 tonnes of steel reinforcement will also help support the station and the buildings to be erected above ground.

The Sydney Metro – Western Sydney Airport project is Australia’s first rail infrastructure to commit to becoming carbon neutral from the start of construction to its completion, and then its operation. That means all the carbon emissions that are to be generated through the life of the project will be reduced and offset by a series of innovative measures. The emissions include those from the manufacturing of materials like concrete and steel, fuel for vehicles and machinery, electricity consumed at the work sites, as well as the waste that will eventually break down in landfills. Measures will include the installation of solar panels at the various sites, part of the commitment made by all projects for Sydney Metro to offset the carbon emissions associated with the consumption of electricity during construction.

From St Marys, the line will run for 23 kilometres to the airport and the adjacent Bradfield site, which is being established for aerospace, healthcare and other industries. Each of the six stations will have its own unique role. After St Marys, Orchard Hills will be part of a commercial and residential precinct, while Luddenham will serve an area dedicated to education, innovation and commerce. When the line arrives at the airport, there will be two stations: one at the business park and the other at the terminal. The sixth one at the end will be at the heart of Bradfield.

The future airport, to be known as the Western Sydney International (Nancy-Bird Walton) Airport, is expected to handle 10 million travellers a year when it opens. This large number reflects how much Sydney is expected to grow in the coming years. According to the Australian Bureau of Statistics, the city added 147,000 people in 2023, mostly due to immigration. That led to Greater Sydney reaching a total of 5.45 million. Western Sydney, meanwhile, is among the fastest growing regions. Its population is expected to grow from 2.0 million to 3.7 million by 2036, underlying the urgency to offer more public transport services to dissuade commuters from using their vehicles, reduce traffic congestion and, consequently, CO2 emissions.

The delivery of the six stations is the responsibility of Webuild and its partners in the Parklife Metro consortium contracted by Sydney Metro. It is called the Stations, Systems, Trains, Operations and Maintenance, or SSTOM, package. With the line’s tunnels and viaducts under development by other builders, the Italian group and its partners will also provide 12 new metro trains, core rail systems and a stabling and maintenance facility. Once everything has been completed, the consortium will operate and maintain the line for 15 years.

Signed in 2022, the SSTOM contract was the largest public private partnership (PPP) in the state of New South Wales. A PPP allows the public and private parties to work close together at every stage of a project, from finance to construction to operation.

Webuild is working on similar projects elsewhere in the world, with construction sites deep in the heart of cities to establish new rail lines and their accompanying stations. In Rome, it is developing the Venezia Station at the historic square of the same name for Line C, which is still under construction. The station will be 40 metres deep with eight levels. In Naples, it recently raised the metal roofing of the future Capodichino station, which will connect the railway, port and airport, a rarity anywhere in the world. Back in Australia, Webuild completed a little more than a year ago the Airport Line in Perth. High Wycombe, one of its three stations, has more than 600 solar panels on the roof, making it the site of the largest solar panel installation by a government department in Western Australia. In the summer, it can meet the energy needs of all three stations.