Getting Down To Business: Early Work Begins On Sydney Rapid Transit

Published: 4 Oct 2016

Released by: The Premier

The NSW Government is wasting no time delivering on its election commitments with early work starting today for the second Sydney Harbour rail crossing.

NSW Premier Mike Baird and Minister for Transport and Infrastructure Andrew Constance announced over coming weeks, geotechnical drilling will occur up to 70 metres below Sydney Harbour to help determine the best location for the new Sydney Rapid Transit railway tunnels.

“During the election campaign we outlined a positive vision for our global city – today we get on with the job of delivering,” Mr Baird said.

“This new rail crossing of Sydney Harbour is the key to increasing capacity on our rail network by 60 per cent – allowing us to move an extra 100,000 people every hour right across Sydney.”

Mr Constance said surface and underwater drilling is a critical part of the design process and will ensure the city’s brand new state-of-the-art rapid transit rail network can be delivered as quickly as possible.

“While construction continues apace on the North West Rail Link, we are already preparing for this vital next stage which will revolutionise the way people get around Sydney,” Mr Constance said.

“Sydney Rapid Transit will turn the city’s crush hour, into Sydney’s rush hour.

“From the end of the North West Rail Link at Chatswood, Sydney’s new rapid transit network will continue under Sydney Harbour, through new railway stations in the CBD and west to Bankstown with capacity for trains to run every two minutes.”

About 30 boreholes will be drilled as part of the Sydney Rapid Transit geotechnical program, with roughly half of them beneath Sydney Harbour and the rest on land either side along the route.

On the harbour, a barge will be towed into position before its four legs are lowered to the seabed as much as 25 metres below the water surface, then pushed to firm ground on the Harbour floor.

The barge will be raised up two metres clear of the water surface to provide a platform unaffected by tides, currents or other water movements.

Boring then starts with a diamond-tipped drill which takes core samples from depths up to 70m below the bottom of the harbour.

To monitor the barge’s interaction with the harbour floor, divers will also be used as an extra visual check, with a preparation dive already completed on Sydney Harbour.

When the drilling work under the harbour is finished, the holes will be filled with cement to create a permanent seal.

It’s anticipated mostly Sydney sandstone and shale will be found along the Sydney Rapid Transit route and the geotechnical work will help better determine the ground conditions for tunnelling, making sure the strength of the underlying rock and groundwater conditions are understood.

Geotechnical drilling will also take place at Sydenham, in the Sydney CBD, North Sydney, Crows Nest and Artarmon.

Nearby communities will be notified by the project team and kept fully informed, and further information will be available on a 24-hour community information line: 1800 171 386

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