The fourth of five mega tunnel boring machines (TBMs) has started tunnelling under Sydney on February 11 that will build 6.2 km tunnels to the edge of Sydney Harbour. Mabel is one of five TBMs that will excavate 5.9 million tonnes of rock, enough to fill about 940 Olympic swimming pools.
TBM Mabel has been launched at Chatswood to help deliver 31 km of tunnels between Marrickville and Chatswood on Sydney Metro, extending the metro system into the Sydney CBD.
Together with TBM Wendy, the rail tunnel towards the new Sydney Metro stations will be constructed at Crows Nest and North Sydney before being retrieved at a temporary construction site at Blues Point.
TBMs Nancy and Mum Shirl, which started work late last year from Marrickville, are excavating 8.1 km tunnels which will pass underneath the CBD and on to Barangaroo. These two TBMs have already built more than 2.5 km of tunnels between them, representing the completion of more than 10 percent of the Sydney Metro tunnelling works.
Sydney Metro’s fifth mega TBM, named Kathleen, specially designed to deliver the twin tunnels under Sydney Harbour, has arrived to begin the first rail crossing deep under Sydney Harbour. The TMB is being assembled at the site of the new Barangaroo metro station, ready for tunnelling works in coming months. Specially designed for the geological conditions under Sydney Harbour, the 975 tonne machine will dig twin metro rail tunnels from Barangaroo to Blues Point.