Beneath the city of Kuala Lumpur in Malaysia, tunnel boring machines are digging almost 20 kilometers of tunnels for the city's new mass rapid transit to help relieve the gridlock above. But digging underground in some of the world's worst tunneling conditions is no easy task. Discover how an innovative tunneling system overcame an array of challenges to construct a key component of the new urban transport system.

Beneath the city of Kuala Lumpur in Malaysia, tunnel boring machines are digging almost 20 kilometers of tunnels for the city's new mass rapid transit to help relieve the gridlock above. But digging underground in some of the world's worst tunneling conditions is no easy task. Discover how an innovative tunneling system overcame an array of challenges to construct a key component of the new urban transport system.