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Chatswood dive site

About Chatswood dive site

The Chatswood dive site was established to support:

  • operation of two tunnel boring machines
  • construction of about 250 metres of new above-ground metro tracks and the realignment of the T1 North Shore Line
  • the fit-out of tunnel rail systems.

Work at the site includes:

  • excavating and constructing the Chatswood dive structure and tunnel portal
  • launching and supporting two TBMs
  • supporting the realignment of the T1 North Shore Line between Chatswood Station and Brand Street, Artarmon to accommodate the new metro tracks
  • supporting the construction of about 250 metres of new above-ground metro tracks
  • supporting the fit-out of the tunnel rail systems
  • installing rail dampers and deck absorption to provide mitigation for operational train noise
  • constructing the tunnel portal
  • constructing a fire protection wall along the entire length of the dive structure to provide separation between the two metro tracks.

Main site features

  • laying around 250 metres of new track in the existing corridor between Chatswood Station and the dive site, in order to connect Sydney Metro City & Southwest to Metro North West Line and the T1 North Shore Line
  • permanently closing the road bridge at Nelson Street, Chatswood
  • realigning the T1 North Shore Line within the existing rail corridor between Chatswood Station and Brand Street, Artarmon
  • constructing a new rail bridge for a section of the northbound track to pass over the metro northern dive structure
  • removing the existing Sydney Trains maintenance access point from Hopetoun Avenue, Chatswood
  • providing a new rail corridor access point from Brand Street, Artarmon.

Dive structures and tunnel portals

Two dive structures and tunnel portals were built, one at Chatswood and another at Marrickville. These sites, along with the Barangaroo Station site, formed the TBM launch sites and provided support for tunnelling operations including:

  • spoil storage and removal
  • pre-cast concrete ring segments storage
  • work trains (or similar) to transport staff and materials to the cutting face
  • water and power supply
  • 24–hour fresh air tunnel ventilation
  • separation plant (Barangaroo only)
  • grout batching plant
  • drainage, water treatment and disposal
  • material storage
  • office facilities, work amenities and parking. 

More information about tunnelling at Sydney Metro.


The dive site is located south of Chatswood Station and north of Mowbray Road adjacent to the T1 North Shore Line at Chatswood. It borders the Pacific Highway, Mowbray Road and Nelson Street.

Planning and compliance

The Chatswood to Sydenham Environmental Impact Statement (EIS) covers the construction and operation of the Sydney Metro rail line from Chatswood to Sydenham.

The EIS was on public exhibition from 11 May to 27 June 2016 and received more than 300 submissions. The Minister for Planning approved the Chatswood to Sydenham EIS on 9 January 2017.

Systems Connect is a Joint Venture (JV) between CPB Contractors and UGL Engineering. The JV has been contracted to convert the excavated tunnel into a working railway for Sydney Metro City & Southwest. Line-wide work includes the permanent systems, services and building works required for metro trains to travel through the Sydney Metro City & Southwest tunnels.

For more information see City & Southwest planning and compliance documentation or Sydney Metro City & Southwest Line-wide Works to find out more about our major contractors involved in the project.

If you are having difficulty locating a document, please contact the City & Southwest project at or call our 24-hour community information line on 1800 171 386.

Artarmon substation and power upgrade

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