Ghella and CPB reach major tunnelling milestone in Sydney Metro project

A joint venture between Italian civil engineering company Ghella and CPB Contractors, has substantially completed the first section of tunnels at its Sydney metro project.

CPB, an Australian subsidiary of German builder Hochtief, announced on its website that it completed section S9 of its Western Sydney Airport, Station Boxes and Tunnelling (SBT) project, which comprises twin 1.2-kilometre-long tunnels running between the Airport Business Park and Airport Terminal sites.

Referred to as portion S9, this completed section is the 1.2-kilometre-long twin tunnels running between the Airport Business Park and Airport Terminal sites. Photo: CPB

The excavation of the S9 portion represents 12% of the SBT project’s 9.8-kilometre tunnel scope of works. The project took about three months, with tunnel boring machines (TBMs) Eileen and Peggy excavating more than 116 thousand tonnes of rock—enough to fill about 18 Olympic swimming pools.

Delivery of this project milestone also included the placement of more than 4,400 precast segments to construct 743 concrete rings.

CPB and Ghella were awarded the A$1.8 billion (US$1.3 billion) contract for the Western Sydney Airport, Station Boxes and Tunnelling (SBT) project by the New South Wales government in December 2021.

Works include the design and construction of 9.8 kilometres of twin tunnels and excavations for stations at St Marys, Orchard Hills, Airport Business Park, Airport Terminal and Aerotropolis and services facilities at Claremont Meadows and Bringelly.