WestConnex shortlists final elements 31 May 2018

Construction of the AUD$16.8 billion WestConnex project in Sydney, Australia, is moving ahead with two joint ventures shortlisted for one of the final elements of the underground highway. The two JVs shortlisted for design-build of the Rozelle Interchange and Iron Cove Link on the M4-M5 Link Stage 3 of the project are:

• SCS joint venture - Salini Impregilo/ Clough Projects/ Samsung C&T
• JCL joint venture - John Holland / CPB Contractors / Lend Lease

Fig 1. Proposed Rozelle Interchange on the M4-M5 Link

The Rozelle Interchange is part of the final stage of the project to connect underground the new M4 and M5 underground highways. The interchange project, commissioned by the New South Wales Government, involves the construction of an underground motorway interchange at Rozelle and underground bypass of Victoria Road between Iron Cove Bridge and Anzac Bridge (Fig 1). It also includes links to the proposed future Western Harbour Tunnel and Beaches Link.

The WestConnex project, which will ease traffic congestion and improve access and connections to western Sydney, comprises five separate contracts delivered in three stages (Fig 2). Work started in early 2015 with the widening of the M4 motorway between Parramatta and Homebush and award of the 7.5km long $498 million contract in 2015 to the CPB Contractors / Rizzani De Eccher Joint Venture. This first part of the mega-project was completed in 2017.

Fig 2. WestConnex bypass for Sydney's city centre

Construction of the $3.8 billion M4 East stage of the project was awarded in 2016 to the CPB Contractors / Samsung C&T / John Holland JV and is 6.5k long, including5.5km three-lane twin tunnels. Excavation using 21 roadheaders across four sites was completed earlier this year after the first underground breakthrough in July 2017 and a further five breakthroughs across four tunnelling sites. Paving and M&E systems installation is now well under way. The underground extension of the M4 is scheduled to open to traffic in 2019.

The $4.335 billion New M5 Stage 2 of the project, to provide twin underground motorway tunnels of 9km long, from Kingsgrove to a new St Peters Interchange, was awarded for construction in September 2015 to the CPB Contractors / Dragados / Samsung Joint Venture. Excavation started in November 2016 and is progressing from three access points and using another fleet of roadheaders through the favourable Hawksbury Sandstone of the Sydney area. The first of six breakthroughs on the project was achieved in May 2018 and excavation is more than half way. The completed underground highway, which will duplicate the M5 East, more than doubling capacity along the corridor, is programmed to open to traffic in 2020.

Excavation of the underground highway

The AUD$7.247 billion M4-M5 Link Stage 3 of the project comprises another 7.5km of twin mainline tunnels, of up to four lanes each, to link the M4 at Haberfield with the New M5 underground highway at St Peters (Fig 1). It also includes the Rozelle Interchange and Iron Cove Link, which features an interchange at Rozelle that will form the transitions between the underground highway and local surface roadways and provide for a future connection to the proposed Western Harbour Tunnel and Beaches Link, another major investment by the New South Wales State Government into the highway system of Sydney. The interchange in Rozelle will be mostly underground and located at the site of the old Rozelle Rail Yards. Construction of the mainline tunnels of the M4-M5 Link is yet to be awarded. Two consortia were shortlisted for the contract in June 2017:

• John Holland / CPB Contractors
• Lend Lease Engineering / Samsung C&T / Buoygues

Construction on the mainline tunnels is expected to start later this year with the Rozelle Interchange and Iron Cove Link to be completed by 2023.

“Construction on WestConnex is about one-third complete, with more than 22 million hours of work clocked up to date,” said Alesha Allen, Media Relations Manager for the project. “WestConnex will be the central spine of Sydney’s motorway network, providing a long awaited underground link between the M4 and M5, creating a seamless motorway without traffic lights. Accommodating through traffic of tens of thousands of vehicles per day, it will bypass up to 52 sets of traffic lights on current surface routes and reduce an average peak journey between Parramatta and Sydney Airport by up to 40 minutes.”

Australia is continuing its ambitious programme of underground infrastructure with underground works for road and rail progressing and being planned in each of the main States. As a projection, the Australian Industry Group has estimated an annual growth rate in roadwork projects in the country at about 21% for 2018-2019, and about 19% for rail projects. The Australian Government plans to invest about AUD$75 billion (US$56.4 billion) in public works, including roads, rail and other transport infrastructure, between 2018 and 2027, constituting about 9% of the gross domestic product.