Enough concrete segments to stretch more than six kilometres into the sky have already been produced for Sydney’s new metro railway.
More than 25,000 of the almost 100,000 concrete segments needed to deliver Sydney Metro under the centre of Sydney have been made at a specialised Marrickville concrete facility.
The 25,000 segments needed more than 91,000 tonnes of concrete, enough to fill 15 Olympic swimming pools.
If the segments produced so far were stacked on top of each other, they would tower more than 6,500 metres high – or more than double the height of Mount Kosciuszko.
Work started at the Marrickville facility in September last year to deliver more than 99,000 concrete segments which will line the new 15.5 kilometre twin metro railway tunnels from Chatswood to Sydenham – including under Sydney Harbour.
Six concrete segments make up one concrete tunnel ring, which is installed underground by a tunnel boring machine as it moves forward. The tunnels will be lined with 16,451 concrete rings.
Three of five tunnel boring machines are now tunnelling under Sydney.
More than 160 people work at the Marrickville facility, producing one four-tonne concrete segment every six minutes.
Most of the equipment at Marrickville was originally used to make the concrete segments for the Sydney Metro Northwest line, which opens to customers in the middle of this year.
In the north west, 98,184 concrete segments were made to line the twin 15-kilometre tunnels from Bella Vista to Epping.