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Sydney Metro Northwest Tunnels and Stations Civil

This project by CPB Contractors Pty Limited, John Holland Group Pty Ltd and Dragados achieved a 'Leading' As Built v1 IS Rating.


The $8.3 billion Sydney Metro Northwest is Australia’s biggest public transport project and a priority infrastructure investment for the NSW Government. It is the first stage of Sydney Rapid Transit, the city’s new rapid transit railway network.

The Sydney Metro Northwest will deliver eight new railway stations, 4,000 commuter car parking spaces and five existing stations upgraded to rapid transit standards. When the Sydney Metro Northwest opens in the first half of 2019, there will be a train every four minutes in the peak – that’s 15 trains an hour. As Australia’s first fully automated railway, customers won’t need a timetable – they’ll just turn up and go.

There are four packages of work registered for IS Rating: Early Works |Tunnel and Station Civils | Surface and Viaducts Civils | Operations, Trains and Systems

About Tunnel and Station Civils The $1.15 billion tunnelling contract was awarded in June, 2013. Tunnel builders Thiess John Holland Dragados are delivering Australia’s longest railway tunnels – 15km twin tunnels between Bella Vista and Epping.

The Sydney Metro Northwest is the first transport infrastructure project in Australian history to use four tunnel boring machines on the one project. The first machine, Elizabeth, started tunnelling in early September, 2014, four months ahead of schedule.

This project is one of four packages of the Northwest Metro Program.


  • Rating Type Rail
  • Rating Score 92.5
  • Registered Date September 2015
  • Certification Date March 2018
  • Jurisdiction Australia
  • States NSW
  • Suburb North West Sydney
  • Assessor Caitlin Richards, James Herbert, Fin Robertson
  • Capital Value $1.15 Billion
  • Other Stakeholders Bingo Industries, Transport for NSW (TfNSW)

Rating Highlights

Management Systems

Full points were achieved for the following credits:

  • Sustainability leadership and commitment 

  • Management system accreditation

  • Risk and opportunity management

  • Organisational structure, roles and responsibilities

  • Inspection and auditing.

The high performance across this credit demonstrates that the project team has excelled in sustainability management and systems.

Procurement and Purchasing

Sustainable procurement commitments have been publicly stated as part of the Sustainability Procurement Plan and are embedded into the sustainability objectives and targets.

TJHD required subcontractors and suppliers to implement sustainable  procurement initiatives that provide environmental and social improvement and meet the requirements of the BS 8903 Principles and Framework for procuring sustainably.

The sustainable procurement objectives and targets are embedded throughout the procurement process via the Subcontractor Environment and Sustainability Pack which is provided to all suppliers and subcontractors. As part of this process suppliers are asked to provide their Sustainability policies and evidence of their implementation.

Energy and Carbon

24% reduction in scope 1 and scope 2 emissions 
Scope 1 reductions have been achieved through:

  • B5 blended fuel

  • Plant selection criteria targeting plant less than four years old

  • Use of hybrid excavators

  • Fuel efficient training and awareness programs

Enforced efficiency routines including regular maintenance of plant and no idling policies for heavy plant.

  • Scope 2 reductions have been achieved through:

  • Design optimisation which reduced the tunnel diameter reducing the quantity of materials to be removed and sent offsite and segment volumes

  • Reduced electricity associated with segment production and handling.


37% reduction in total water use below a reference footprint.

This efficiency is entirely down to the closed-loop recirculation networks that are responsible for cooling on all four of the TBMs. Usually, 100 per cent potable water would be used for TBM cooling in tunnelling projects.

All initiatives with a payback period of less than four years and at least one with a payback period of more than four years has been implemented:

  • TBM cooling closed-loop design

  • Rainwater tank – Kellyville precast

  • Water carts using recycled water.


45 per cent reduction in ecopoints below a reference footprint. 

Significant improvements resulting in material reductions have been achieved as TJHD’s design uses an innovative concrete mix for the high-strength concrete used in the tunnel lining segments. A significant material efficiency in concrete used for segments was identified, reducing the amount of concrete from 680 kt 50 MPa concrete to 350 kt 50 MPa with 20 per cent supplementary cementitous material (SCM) (90k EcoPoint reduction). This was due to a reduction in segment thickness from 370 mm (base case) to 260 mm and a reduction in defects rate from 10 to 0.5 
per cent. The mix uses:

  • Polypropylene steel fibres used to strengthen precast concrete segments which significantly reduced the need for reinforced steel. This resulted in carbon footprint reductions 

  • Fine graded aggregates with silica fume and additives to improve the workability of the mix even with low water content.

Discharges to Air, Land & Water

Best practice noise, vibration and air quality management to be used during construction.

Use of a comprehensive noise management approach in line with the NSW Interim Construction Noise guideline.


Best practice flood immunity has been demonstrated.

The station excavations are protected from the Probable Maximum Flood event 

  • Provision of pumps and sumps

  • A flood management protocol

  • Flood barriers.

Urban and Landscape Design

Applied the Australian Urban Design Protocol People and Place principles to the TSC temporary works.


Presented the TBM traverse and relaunch methodology as a world first.

Presented their approach to workforce training onsite as an innovation which currently sits outside the scope of the IS rating tool.