5.9km under the Brisbane River and central business district

Excavation of the Cross River Rail twin running tubes has begun in Brisbane, Australia. Both TBMs and roadheaders will excavate the 5.9km underground section of the new 10.2km rail link between Dutton Park in the south of the city and Bowen Hills in the north (Fig 1).

Two 115tonne roadheaders, previously used to excavate the new Woolloongabba Station cavern, are 30m into excavation of the 870m twin tubes between Woolloongabba and the new Boggo Road Station site. The 22m-long machines will excavate at a rate of 60tonne/hour to remove 86,000m³ of muck. They will also excavate three cross passages at 240m intervals and a temporary cross passage.

In total, six roadheaders are working on the project for contractor CPB Contractors-Ghella-BAM International JV, excavating the station caverns at Roma Street and Albert Street, as well as at Woolloongabba and the southern portion of the twin alignments.

Woolloongabba is also the launch site for the two 7.2m diameter refurbished Herrenknecht TBMs that will drive the northern 5km of the route. The first machine launched in January 2021 and has so far installed the first two of 25,000 concrete rings that will line the alignments, a spokesperson for the Cross River Rail Delivery Authority told TunnelTalk. Each ring weighs 4.2tonne and comprises six segments.

Roadheaders begin excavation south from Woolloongabba

The second TBM is now being assembled in the Woolloongabba Station box and is expected to launch soon, the spokesperson added. Previously used to excavate the Sydney City and Southwest Metro, the TBMs will drive under the Brisbane River and the central business district, through the Roma Street and Albert Street Stations, before emerging at the northern portal.

With both roadheaders and TBMs breaking through by the end 2021, excavation of the entire 5.9km route is expected to be complete within twelve months.

After being awarded the AUD$5.4 billion contract to deliver the 10.2km long Cross River Rail project in Brisbane, Australia, in April 2019, the Pulse consortium is making progress on the 5.9km underground section of twin tunnels under the Brisbane River and the city business district and excavation of four new underground stations at Boggo Road, Woolloongabba, Albert Street and Roma Street.

Fig 1. Twin TBMs will progress north from the Woolloongabba Station site

Woolloongabba Station construction site south of the city centre

The Pulse consortium, comprising the CIMIC Group companies, Pacific Partnerships, CPB Contractors, and UGL, with international partners DIF, BAM, and Ghella delivering the new railway and ongoing maintenance services; the CPB Contractors-Ghella-BAM International JV delivering the design, construction and underground excavations; and UGL delivering the mechanical and electrical works and providing maintenance services for a 24-year period.

Eight working job sites have been established across the project alignment and open cut and shaft sinking has permitted start of roadheader excavation at underground station sites including at Roma Street where a 280m long cavern will be constructed at about 27m below ground level.

Two refurbished 7.2m diameter Herrenknecht TBMs, that worked previously on the Sydney Metro City and Southwest Line, arrived in Brisbane in August 2020 for refurbishment in a Herrenknecht facility to the north of the city. New shield cans of a different size are being delivered from Herrenknecht China for a full factory refit and ahead of TBM launches in early 2021.

The TBMs will launch from the Woolloongabba Station south of the city and advance under Brisbane River to the Albert Street Station, continue to the new Roma Street Station and break through at the project north portal at Normanby (Fig 1). Roadheaders will excavate the running tunnels to the south portals at Dutton Park.

Roadheader excavation underway at Roma Street Station

Work has also begun at the Wagners Precast facility at Wacol, to produce the 25,000 concrete segments to line the twin running tunnels.

Wagners Precast at Wacol is a 100 per cent Queensland-owned company and just one of more than 400 Queensland based supplier and sub-contractor companies that are benefitting from the construction of Cross River Rail now that work is underway.

Major infrastructure projects like Cross River Rail also mean more jobs just when the economy needs them most, and the workforce at Wacol will grow from 15 to 70 while the company produces and delivers the segments over the next 10 months.

In total, Cross River Rail is pumping over $4 million a day into the economy and Wagners’ work with Cross River Rail is a great example of what can be achieved by prioritising local companies and local employees.

Work began in July 2020 at the Wagners Precast facility at Wacol, which is contracted to produce the 25,000 segments line the twin tunnels in 1.7m long x 270mm rings of six segments/ring. The Wacol facility covers more than 70,000m² with a segment storage area of 28,000m². “Covid obviously had everyone worried,” said Wagners CEO Cameron Coleman, “so it is fantastic that the Government has been able to keep going with construction of Cross River Rail.”

A project timeline has the tunnel excavation works completed by early 2023 and the M&E and rail systems installed by end 2023 for beginning of commissioning towards start of public train services in 2024 (Fig 2).

With the Cross River Rail contract finalised, the major contractors are moving to mobilise their workforces. Construction will commence later in 2019 as scheduled.

The Cross River Rail route, which will integrate with Brisbane Metro services

Pulse, the consortium selected as the preferred proponent in April 2019, will deliver the Tunnel, Stations and Development major construction works, as part of a public-private partnership package. Comprising the CIMIC Group companies, Pacific Partnerships, CPB Contractors, and UGL, with international partners DIF, BAM, and Ghella, the consortium will deliver tunnelling works, new underground stations, and ongoing maintenance services. CPB Contractors will deliver the design and construction in a joint venture with Ghella and BAM International, with UGL delivering the mechanical and electrical works. UGL will also provide maintenance services for the project over 24 years.

The State Government is providing an AU$5.4 billion capital contribution for construction. The Pulse consortium sponsors and equity providers are Pacific Partnerships (49%), DIF (26%), BAM PPP PGGM (15%), and Ghella Investments and Partnerships (10%).

The rising population in South East Queensland has put its transport network under pressure, constrained by a single rail river crossing in Brisbane with all lines running through the same four city centre stations. Driven by population and employment growth in the region, demand for passenger rail services is forecast to almost triple by 2036. The Cross River Rail project will unlock the bottleneck into the Brisbane Central Business District (CBD) by delivering a second river crossing, allowing more trains to run more often and integrating with new roads and bus services to enable an easily accessible public transport system across the entire region.

As the largest infrastructure project in South East Queensland, Cross River Rail includes design and construction of a new 10.2km rail line from Dutton Park to Bowen Hills, including 5.9km twin tunnels under the Brisbane River and the CBD, and four new underground stations at Boggo Road, Woolloongabba, Albert Street and Roma Street.

Albert Street station in the CBD will span 294m – effectively two entire city blocks underground. As the first CBD train station built in the city in over 120 years, it will also be the deepest station on the network at 31m below street level. The new station is expected to be the busiest of the four new underground stations, with almost 70,000 passengers projected to use the station every weekday by 2036. Woolloongabba and Roma Street stations will both be 27m below street level and will have 220m platforms to accommodate nine-car trains to provide for additional future capacity, while Boggo Road station will be 19m below street level. The Woolloongabba site will become the staging area for the TBMs and roadheaders before becoming the location of the new underground station.

Construction of Cross River Rail is due to complete by 2024, after which a detailed commissioning and testing programme will begin.