Sydney Metro have released the following information about proposed works at the Dive site at the corner of Mowbray Rd and the Pacific Highway.
The dive site is being used to launch two tunnel boring machines (TBMs).The dive structure is about 400 metres long and includes an open section before closing into a tunnel portal.
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.
- 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 Sydney Metro Northwest and the T1 North Shore Line
- Carrying out road works at the intersection of Pacific Highway and Mowbray Road (Chatswood) to provide new double right-turn lanes from Pacific Highway southbound into Mowbray Road westbound
- 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 are being built, one at Chatswood and another at Marrickville. These sites, along with the Barangaroo Station site, form the TBM launch sites and provide 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.
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.