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In 2021, Cross River Rail embarked on its year of tunnelling – an ambitious task that saw two massive Tunnel Boring Machines dig twin tunnels beneath the Brisbane River and CBD.
The two 1350-tonne mega machines – named after trailblazing engineer Professor Else Shepherd and pioneering feminist Merle Thornton – began their journey from the Woolloongabba station box at the start of the year and made their 3.8km journey underground, both emerging from the project’s northern portal at Normanby before Christmas.
Meanwhile, two 115-tonne roadheaders excavated the almost 900 metres of twin tunnels south from Woolloongabba to Boggo Road.
At the peak of tunnelling, more than 450 people were working on Cross River Rail’s twin tunnels, while 80 tunnel workers were able to complete an apprenticeship or traineeship.
With tunnelling complete, the project’s focus shifts towards station fitout, with permanent station structures starting to take shape, and mechanical and electrical equipment installation commencing.
Cross River Rail tunnelling fast facts:
- At the end of last year, TBMs Merle and Else broke broke through at Cross River Rail’s northern portal, having each excavated 3.8km of tunnel since launching from Woolloongabba in early 2021.
- TBMs excavate the bulk (3.8km) of Cross River Rail’s 5.9km twin tunnels, with the rest excavated by roadheaders.
- The TBMs have excavated 310,000 cubic metres of spoil and installed approximately 27,000 concrete segments to line the tunnel’s walls, each weighing about 4.2 tonnes.
- At their deepest point, the TBMs tunnelled 58 metres below the surface of Kangaroo Point, and 42 metres below the Brisbane River.
- Each TBM weighs 1,350 tonnes and is 165 metres long.
- A crew of up to 15 people work in a TBM at any one time.
- TBMs work at a rate of 20 to 30 metres a day.
- Roadheaders excavated 85,000 cubic metres of spoil while tunnelling almost 900 metres from Woolloongabba to Boggo Road.
- The roadheaders are 22-metres long and weigh 115-tonnes.
Cross River Rail embraces fantastic plastic solution
In a first for Queensland’s rail network, Cross River Rail is using recycled plastic fibre reinforcement for concrete during construction of the new Mayne Yard North stabling facility.
Known as eMesh, the innovative material is more sustainable, safer and cost-effective than typical steel reinforcement used on large projects, as it requires less effort handling and cutting.
The eMesh fibres, each about 47mm long and 1.7mm wide, act as mini reinforcing bars mixed throughout the concrete.
In fact, a standard eMesh concrete would have more than 120,000 fibres in every cubic metre.
The material is made from 100 per cent recycled Australian plastic waste, and can even be reused again in the future.
The specific material used, polypropylene, is the second most widely used plastic in the world and has the lowest recycling rate – estimated at below one per cent.
Polypropylene is one of only three types of plastics that floats, forming a huge part of the estimated eight million tonnes of plastic entering the ocean each year.
And in an added bonus, Fibrecon, the company behind eMesh uses National Disability Insurance Scheme (NDIS) workers to pack the concrete fibres, supporting about 90 jobs.
There are plenty of other examples of Cross River Rail’s commitment to sustainability and recycling, including the use of sand made from recycled glass.
Also, more than 80 per cent of the spoil generated on the project so far has been reused or is being stockpiled for reuse.
One of the more interesting uses is at Austral Bricks at Rochedale, which is using 60,000 cubic metres of Cross River Rail spoil to make bricks for houses.
Designs for Boggo Road station’s game-changing bridge released
Designs have been released for a new pedestrian and cycle bridge that will connect a new Cross River Rail underground station with existing transport infrastructure, at the heart of Brisbane’s Boggo Road health, science and education precinct.
The 480-metre-long bridge crossing freight and passenger rail lines will link the new Boggo Road and existing Park Road rail and Boggo Road bus stations west of the tracks, with the Princess Alexandra Hospital and the PAH South East Busway platforms to the east.
The bridge will provide faster and more convenient walking and cycling connections, easier access to the local cycle network and improved connectivity to public transport services.
It will be a game-changer for the local community as well as those who work, who study or who are treated at the many world-class facilities now located at Boggo Road.
The new bridge, which included lifts on both sides, dedicated cycle and pedestrian paths, seating, shade and rest stops, will be accessibility compliant and is designed to meet safety requirements to pass over the rail corridor.
A name for the new bridge has not yet been selected and there will be an opportunity for the public to contribute ideas.
For example, it could be named after somebody local, who has a track record of service and creating community connections, even someone linked to health, science and education or take a name that honours local First Nations culture.
The bridge and the new underground station it connects to will see Boggo Road become South East Queensland’s second busiest transport interchange, with over 22,000 commuters using the new station each weekday by 2036.
It will also stimulate the growth of what is already a world-class health, science and education precinct, where thousands of people already work and where thousands of jobs will be created in the future.
Construction is due to commence from March and is expected to be completed in late 2023.
Boggo Road bridge fast facts:
- A new cycling and pedestrian bridge will be delivered at Boggo Road as part of Cross River Rail.
- It will be an architecturally designed cable stay bridge, approximately 480 metres long, with the cable stay spire approximately 45 metres high.
- The main deck level will be about 20 metres above the ground, and it will be up to 6.25 metres wide.
- It will consist of more than 1600 tonnes of steel, 1.2 kilometres of hand rail, more than 16 kilometres of welds, 43 metre tall pylons, 683 metres of cable stay, and five individual steel girders weighing up to 133 tonnes each.
- Key features include lifts on the eastern and western sides, dedicated cycling and pedestrian paths, seating and rest stops, shade and planting at both ends and rail corridor security mesh.
- The western entry will be via a grade-separated path off Peter Doherty Street, with the bridge crossing over the rail line and linking into the existing bikeway near the Princess Alexandra Hospital Busway station.
Source: © Cross River Rail Delivery Authority 2021 (some changes were made) sourced on 12/03/2022
Source: © The State of Queensland 2021
