First tunnel award for Sydney WestConnex 10 June 2015

The Leighton/John Holland/Samsung C&T joint venture is awarded A$2.7 billion construction of the 7km-long M4 East highway extension in Sydney, including 5.5km of twin tunnels.

Fig 1. The WestConnex Project

Leighton and John Holland are now teamed up for the first time since the latter was sold by the former, for $1.15 billion, to CCCC International Holding Ltd, a wholly owned subsidiary of the China Communications Construction Company.

The award is made by the WestConnex Delivery Authority as part of Phase 1 of an ambitious $11.5 billion program of highway improvements to the east of Sydney. Award of Phase 2, which includes up to 6km of three-lane twin running tunnels and duplication of the existing 3.8km long M5 tunnels, is expected in the coming weeks (Fig 1).

Construction procurement of Phase 3 has not yet started, but includes 8.5km of TBM-bored twin running tunnels that will connect Phases 1 and 2 to complete a high-speed eastern ring road connection between the M4 and M5, and facilitate access to Sydney Airport.

It now appears from the latest project planning map (Fig 1) that the three phases of WestConnex will create a continuous tunnel of some 30km in length.

A challenging project scope for the Phase 1 award includes 5.5km of three-lane wide cut-and-cover twin tunnels to a maximum depth of 35m. The alignment, which will extend the existing M4 further east for onward connection with the City West Link towards central Sydney and with the Phase 3 connection to the M5, will run under the existing Parramatta Road.

Full design of the M4 East tunnel has not yet been revealed, but a WestConnex spokesman told TunnelTalk: “An environmental impact statement is being prepared for the preferred design and this will be available for community comment in mid-2015.”

In addition to the main tunnel, an entry and exit point is to be constructed in the Concord Road vicinity to enable local traffic to access the tunnels and the main highway system once Parramatta Road is restored. Provision is also included for an open southbound connection with the future Phase 3 bored tunnel.

The tunnels lie an average 35m below ground level

Construction is scheduled to begin in the middle of next year (2016), following the completion of a final environmental impact statement and granting of the necessary planning approvals. A three-year building period is envisaged.

Delivery of all three phases of the 33km WestConnex Project is expected by 2023. It is currently the largest infrastructure project, in terms of its cost, in the country.

John Holland Group Managing Director Glenn Palin said: “WestConnex is the largest integrated transport and urban revitalisation project in Australia, bringing together a number of important road projects to form a vital link in Sydney’s Orbital Network. Our tunnelling expertise has been deployed on many major infrastructure projects worldwide and we’re pleased to be able to contribute to the economic growth of Sydney with a project that eases congestion, creates jobs and connects communities.”

Hans Whang, Head of Civil infrastructure Business Unit of Samsung C&T, said: “Samsung C&T is on a fast track to establishing its name as a leader and key player in the civil infrastructure sector in Australia. Samsung C&T expands its presence in Australia by forming strategic partnership with leading companies like Leighton Contractors and John Holland. We are certain that by working closely together with our trusted partners, the project will be successful.”