Look deep underground at new Martin Place metro station

Two roadheader tunnelling machines are working 24-7 to excavate the new Martin Place metro station, which stretches underground between Hunter Street and Martin Place.

The new Martin Place metro platforms run about 25m underneath Castlereagh and Elizabeth streets. The platform caverns will be about 220 metres long, 16 metres high and 14 metres wide when fully lined with concrete.

Four new Sydney Metro stations are being built in the Sydney CBD– at Martin Place, Pitt Street, Barangaroo and Central.

The Martin Place roadheaders have excavated more than 166,620 tonnes of crushed rock – enough to fill about 26 Olympic swimming pools.

Roadheaders have a boom at the front which can carve out different geometrical shapes underground, unlike tunnel boring machines which can only build round tunnels.

About 95 workers are currently excavating the station site and work will soon start at the southern end of Martin Place to connect into the suburban railway station.