Sydney Harbour Tunnel

The Sydney Harbour Tunnel project was designed to reduce congestion on the Sydney Harbour Bridge, and commissioned by the NSW State Government. Awarded to Transfield Pty Ltd and Kumagai Gumi in 1987, it was one of Australia’s first significant Build Own Operate Transfer (BOOT) projects, and possibly Transfield’s most widely known.

Transfield and Kumagai formed the 50/50 Joint Venture to construct the $750m, 2.3km  tunnel ­– with structured private finance underwritten by the toll revenue. Work started in 1988 on the 4 lane, (2 lanes each way) project, and opened to the public in 1992, at which time a 30-year Operating and Maintenance agreement commenced.

Whilst the tunnel works proceeded on either side of the harbour, reinforced concrete caissons were being constructed in Port Kembla. These ‘tubes’ were then floated up the coast and lowered into position onto the sea bed.

In 1997, following the division of the Transfield assets between the Belgiorno-Nettis and Salteri families, the ongoing O&M contract was split between Kumagai (50%), Transfield (25%) and the newly created Olbia (25%)

In 2022, at the time of the handover back to the Government, the average daily usage was a total, in both directions, of approximately 90,000 vehicles.


From the Transfield Archives