Variable density tunnel boring machines (TBMs) have been procured by main contractor MMC Gamuda KVMRT on its the second Mass Rapid Transit line project in Malaysia.
The four new TBMs from Herrenknecht have been specified to efficiently manage expected ground condition challenges on the Sungai Buloh-Serdang Putrajaya (SSP) line.
The 6.6m diameter TBMs will drive the 13.5km underground section of the new 52.2km SSP Line and work alongside eight TBMs procured for use on the first line.
The new TBMs feature upgraded rotary crusher compartments, stronger cutting teeth and improved shield to overcome blockage issues encountered during construction of tunnels for the first line.
Ground conditions on the route of the new line are expected to vary from hard and abrasive granite through to karstic limestone zones, which have been described as “tricky”.