megaprojects

Millie, Alice, Joan and Meg “reach the finish line”

FOUR huge tunnel boring machines have finished 20 months of digging under Melbourne to create two nine kilometre-long, 6.3metre-high rail tunnels lined with around 250,000 tonnes of concrete for the Metro Tunnel Project.

The work included tunnelling just 1.5metres underneath the City Loop as trains continued to run, as well as digging 12 metres under the Yarra River bed and around seven metres below the Burnley Tunnel.

TBM Meg arrived at the Town Hall Station site 25 metres under Swanston and Collins streets, following Millie, Joan and Alice, which have broken through at the station over the past month.

TBMs Joan and Meg – dug their final 670 metres under Swanston Street from the State Library Station site over the past three months. TBMs Millie and Alice – began tunnelling in December to complete their final 1.8km leg under St Kilda Road and the Yarra River.

It’s been a large task for the four machines, which have tunnelled on six separate legs between Kensington and South Yarra, installing more than 55,000 curved concrete segments to create a waterproof tunnel lining.

The TBMs have dug as deep as 40 metres below ground (under the northern end of Swanston Street) and tunnelled through basalt rock, gravel and silt and clay.  After starting work progressively from August 2019, the TBMs tunnelled an average of 90 metres a week, with TBM Alice recording the best rate of 195 metres in a single week.

The machines have removed 600,000 cubic metres of rock and soil, or around one third of the total 1.8 million cubic metres to be excavated for the entire project – enough to fill the MCG 1.2 times.

While the TBMs have finished the rail tunnels between the project’s five stations, roadheaders – huge digging machines excavating the CBD station caverns – are still at work digging the final section of tunnels alongside the platforms at Town Hall Station.

With their work in Melbourne finished, the four TBMs are being dismantled underground and retrieved, with the ‘skin’ of each TBM shield to remain in the tunnels to form part of the permanent lining. The remaining components will be assessed for potential reuse on other tunnelling projects.

Attention now turns to the next phase of works on the project, with construction well underway on the 26 cross passages – the short tunnels that connect the main tunnels and are an important safety feature for passengers should an incident occur. With the tunnel entrances at South Yarra and Kensington completed, work has also begun to connect the entrance structures to the tunnels.

Transport infrastructure minister Jacinta Allan said this was a “huge milestone” for the team at Metro Tunnel.

“This vital project is a year ahead of schedule but there’s still with a huge amount of work to be done to finish the stations and get the tunnel ready to deliver more trains, more often,” Allan said.

“Projects like the Metro Tunnel will connect key locations including the Parkville medical and education precinct, St Kilda Road and the Arden Precinct to the rail network for the first time and is supporting thousands of jobs.”

New rail security fencing set to save lives

New fencing is expected to not only improve safety but also help save lives. WORK has begun on installing additional security fencing on the Sydney Trains network to prevent trespassing and reduce self-harm incidents in the rail corridor.

Transport minister Andrew Constance said the $4.5 million of new fencing was being installed across 2.3 kilometres of the rail corridor by the end of 2021.

“This new fencing will not only improve safety and stop people accessing the rail network illegally, it will also help save lives,” Constance said.

“Tragically, 16 people lost their lives on the NSW rail network last year. There were also 155 near misses and 54 people injured from trespassing or entering the Sydney Trains rail corridor.”

Mental health minister Bronnie Taylor said any suicide was a tragedy with profound community impacts.

“We know that when we erect physical barriers in identified suicide ‘hot spots’, it significantly reduces the immediate risk to that individual’s life,” Taylor said.

“I encourage anyone who is having suicidal thoughts to seek help, or talk to a trusted friend about their feelings immediately.”

Sydney Trains acting chief executive Pete Church said while most of the Sydney Trains network was already fenced, there were locations where people had been able to access the rail corridor.

“When people trespass in the rail corridor, they not only risk their life, but their actions can have a long lasting impact for their friends and family, as well as our customers and staff,” Church said.

TrackSAFE executive director Heather Neil said they worked closely with Sydney Trains to raise awareness of rail safety issues, and reduce near misses.

“Reducing accessibility to train lines through the installation of fences and other physical barriers is known to be a successful method of reducing trespass and self-harm incidents,” Neil said.

There were more than 2,600 trespassing incidents on the network, including nine people caught train surfing, in the 2019-20 financial year. The minimum fine for trespassing is $400 but can be as high as $5,500.

Other Sydney Trains initiatives to prevent trespassing and self-harm incidents include:

  • Training for frontline staff to help them recognise the warning signs for suicide.
  • Emergency help points on every platform, which are directly linked to trained security operators 24 hours a day.
  • More than 12,000 CCTV cameras monitoring the network, including high-definition cameras with stronger capabilities to identify trespassers.

If this article has raised issues for you, please consider calling one of the following entities:

  • Lifeline 13 11 14
  • Suicide Call Back Service 1300 659 467
  • NSW Mental Health Line 1800 011 511