World's first variable density tunnel borer travels its first kilometre

KUALA LUMPUR: The world’s first variable density tunnel boring machine (TBM) broke through the wall of the Pasar Rakyat MRT station here, heralding an important milestone in tunnel construction in the country.

The TBM, named Cochrane 2 (after the Cochrane station where it began its journey), was specially designed to tackle underground karst (limestone) that can be found at many places in Kuala Lumpur.