Property and Infrastructure Specialists
Serving as the Independent Certifier for Australia’s longest railway tunnels – part of the $8.3B Sydney Metro Northwest project, the first stage of Australia’s biggest public transport project.
Transport for NSW
Northwestern Sydney, NSW

Australia’s biggest public transport project

The NSW Government, through Transport for NSW, is delivering Australia’s biggest public transport project.

Sydney Metro will provide 31 metro stations and more than 65km of new metro rail, from Rouse Hill in the booming Northwest region, via Castle Hill, Epping and Chatswood, under Sydney Harbour and beyond to Sydney’s Southwest.

Stage 1: Sydney Metro Northwest

Sydney Metro Northwest is the first stage of this massive undertaking. The Northwest tunnels and stations civil contract included detailed design, construction and handover of:

  • 15.5km of twin, 6m-diameter, TBM-driven tunnels
  • Cross passages
  • Nozzle enlargements
  • Station excavations
  • Services facility shafts
  • Connection to the existing railway at Epping
  • All associated civil works. 

The contract also included:

  • Procurement of tunnelling plant and equipment
  • Establishment and reinstatement of work sites
  • Spoil handling systems, spoil removal and disposal
  • Adjustment and provision of utility and other services to support tunnel construction and station excavation.

Expert independent verification

With such a complex, large-scale heavy infrastructure project, government and key stakeholders need a high level of confidence that everything is being delivered in accordance with the contract requirements.

They achieve this by engaging an independent consultant to certify the design and construction throughout the project. They selected APP for this role because of our extensive independent verification experience and exceptional level of technical expertise, skills and knowledge.


As independent certifier our role was to review and verify that all tunnels, surface works and associated infrastructure were designed and constructed by the contractor to the requirements and specifications set out by Transport for NSW, and other stakeholders such as RMS.

An experienced and dedicated APP team carried out our role using highly refined systems and procedures. We have evolved these procedures over many years of providing a premier independent assurance service to our clients.

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