roadheaders

Dual roadheaders excavating Cross River Rail tunnels

Two roadheaders are excavating tunnels underneath Brisbane to carve out the route of the future Cross River Rail.

The addition of the second roadheader enables more rock to be excavated each day, with 55 metres of tunnel already excavated at a rate of 1.5 metres each a day.

The over 100 tonnes roadheaders have set out in different directions from the Woolloongabba site. Beginning from the station cavern, one is heading north underneath Vulture Street, and the other is tunnelling south towards the South East Busway.

Blasting is also being conducted at the site to speed up excavation works.

To allow for the excavated rock, including volcanic Brisbane Tuff and conglomerates forming the Neranleigh Fernvale rock that sits under the Brisbane CBD, to be removed from site, a spoil shed built by a local contractor has been constructed at Woolloongabba. By the time excavation is complete, over 132,000 cubic metres of rock and soil will have been excavators. So far, 70,000 cubic metres has been removed.

When complete, the station box shaft will be 32 metres deep, with the future 220 metre-long platform sitting 27-metres below the surface.

Later in 2020, tunnel boring machines (TBMs) will arrive at Woolloongabba. The TBMs are currently being refitted in Brisbane after having completed work on the Sydney Metro project. The TBMs will excavate the twin underground tunnels to the north from January next year. This will speed up tunnelling progress as each can carve out 20-30 metres of tunnel a day.

TBMs

TBMs head north for CRR duties

Two tunnel boring machines (TBMs) that were in use on the Sydney Metro project have been shipped north to begin digging twin tunnels under the Brisbane river for the Cross River Rail project.

Queensland Premier Annastacia Palaszczuk said the machines have arrived and are being prepared to start major tunnelling for the underground rail project.

“They are the same machines that dug the Sydney Metro. Now they’ll get a full refit and refurbishment at Herrenknecht’s north-side facility, to prepare them to dig Brisbane’s first underground.”

The two TBMs will excavate the twin tunnels that will connect the rail lines north and south of the Brisbane CBD via a new river crossing. The machines will be launched from Woolloongabba Station on Brisbane’s south-side and emerge at the project’s northern portal at Normanby.

During tunnelling, the TBMs will carve through the Albert Street and Roma Street stations sites. The TBMs will travel 30 metres a day and line the tunnels with concrete segments as they create the passages. An expected 290,000 cubic metres of soil will be generated over the course of tunnelling.

Each of the TBMs weighs 1,350 tonnes and is 165 metres long. At its peak, refurbishment work will be done 247 at Herrenknecht’s site in Pinkemba.

Palaszczuk said that preparing the TBMs to work on the Cross River Rail project will create local jobs.

“More than a dozen people have started working on the refit of the Cross River Rail TBMs, and that will increase to up to 35 people during peak activity – local jobs at a local factory.”

State Development Minister Kate Jones said these jobs would have a long-term benefit to Queensland.

“Cross River Rail will transform the way we travel and it will also leave behind a legacy of skilled workers trained by world-leaders in specialist trades,” said Jones.

Two more tunnel boring machines in the ground under Melbourne

The construction of the Melbourne Metro Tunnel has reached another milestone, with all four tunnel boring machines (TBM) now in operation.

TBM Millie, named after Victoria’s first female MP, Millie Peacock, is excavating the 1.7km tunnel between Anzac Station and the eastern entrance to the Metro Tunnel at South Yarra, while TBM Alice, named after wartime medical hero Alice Appleford, will soon begin on the second under St Kilda Road in the next weeks.

The first two tunnel boring machines had reached Anzac station from the west and are now creating the twin tunnels from Arden Station to Parkville station. There, the excavation of the station box was completed earlier in April.

Other works currently progressing at excavations under Swanston and Flinders streets to create the Town Hall station central cavern. The tunnelling for the twin tunnels under the CBD at the new State Library station, will begin later in 2020.

During these construction works, and with the building of rail infrastructure deemed an essential service, extra safety precautions are in place, said Minister for Transport Infrastructure, Jacinta Allan.

“The Metro Tunnel team are doing an amazing job finding practical, safe ways of working, so we can continue building this urgently needed project in challenging circumstances.”

As states begin to lift coronavirus (COVID-19) restrictions, the continuation of infrastructure construction such as the Melbourne Metro Tunnel will be key for economic recovery, said Allan.

“Just as we’re facing an unprecedented health challenge, we’re facing an unprecedented economic challenge too. Our Big Build will be vital as we recover after the pandemic has passed.”