Second stage of Western Harbour Tunnel begins

Drilling has begun on the second stage of Sydney’s long-planned Western Harbour Tunnel, with the first roadheader machine breaking through sandstone in Cammeray on Monday.

Once complete, the tunnel will connect motorists between the Warringah Freeway and Rozelle Interchange, allowing motorists travelling between the north and west to bypass traffic in the CBD, linking to the junction of dozens of tunnels under Rozelle. The government hopes it will ease congestion on the Harbour Bridge, Harbour Tunnel, Anzac Bridge and Western Distributor.

The tunnel was as initially planned to be attached to the Beaches Link, the motorway connecting the city to the northern beaches. But Labor ditched the project in September amid increasing pressure on the state’s budget and advice from Transport for NSW. Roads minister John Graham said spending $10 billion on the link would be “irresponsible” in the current economic climate.

The first tunnelling work commenced in Cammeray on Monday, as a 100-tonne road header cut through Sydney’s famed sandstone. It is set to cut through 1000 tonnes of rock every day, getting between 20 to 25 metres closer to the harbour each week.

Once it reaches the water, a tunnel-boring machine will be used to dig through bedrock until it reaches Birchgrove on the southern side of the harbour.

The first stage of the tunnel project, cutting the tunnel from Rozelle to Birchgrove, has begun and is due to be completed in 2025.

Original plans showed the government had prepared to lay tubes on the harbour floor, but the Herald revealed last year that machines the width of three lanes of traffic would instead be used below the floor.

The road header that began drilling is one of the 10 metres-tall orange and yellow machines to be used across the project. A sea urchin-like ball, with dozens of metal points, rubs away at the sandstone as a huge air vent removes the dust.