WORK on the second Sydney Harbour rail crossing — which will move 100,000 extra people on Sydney’s trains every hour — has begun.

Preparation began yesterday for drilling to depths 70m below the Harbour — to occur over the next few weeks — to find the best spot for the new Sydney Rapid Transit railway tunnels.

NSW Premier Mike Baird said the government was delivering on its election promises.

media_camera Picture: NSW Government

“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 Baird said.

Transport and Infrastructure Minister Andrew Constance said drilling was the first step to ­unclogging the city’s public transport system.

Already under construction, the North West Rail Link connecting to Chatswood will link to the second crossing.

“This next stage will revolutionise the way people get around Sydney,” Mr Constance said.