Tender and estimating support on the Western harbour tunnel project

Tender bid support via Mechanical & Electrical consulting engineering services – Tunnel Infrastructure



Western Harbour Tunnel (WHT), is a north east extension of the WestConnex motorway connecting from Rozelle in the South to the Warringah Freeway in the north including a second harbour road crossing. The project includes approximately 7km of twin tunnels, integration with the existing WestConnex as well as enabling works for the future beaches link.



RSGx was engaged to support the ACCIONA tender bid with engineering services in the M&E area. RSGx worked as an integrated team with ACCIONA providing engineering design, procurement and estimating and constructability support. RSGx also led the coordination of systems with the broader project. Disciplines included:

  • Combined services
  • Tunnel Ventilation
  • Mechanical and drainage
  • Fire systems
  • HV/LV electrical and tunnel lighting



The tender design solution included longitudinal ventilation using jet fans with portal exhaust and air exchange facilities. Power was supplied via a 22kv reticulation in the tunnel through a series of underground and above ground substations. Fire systems included a deluge system, with redundant water storage and fire pump rooms combined with AVID and linear heat detection fire alarm systems.



  • Successfully challenging the SWTC to ensure value for money outcomes in the tunnel ventilation design.
  • Reducing the total number of ventilation fans to reduce capital costs, improve maintenance access and reduce ongoing whole of life costs.
  • Successfully coordinating MEP services across multiple tunnel configurations with a focus on optimising tunnel volumes.
  • Optioneering prefabricated equipment in various above and below ground locations for the best value for money solution at each location.