Sydney's Super Tunnel Episode Rating Graph

The show kicks off with a dynamic taster of what the series has in store - namely the inside story of a crack team building a trailblazing, fully-automated metro system costing $50 billion.

We check in on our engineers encountering all manner of issues tunnelling through a minefield of existing infrastructure - skyscraper footings and basements, sewers, a graveyard, and rail tunnels.

Another super challenge looms, perhaps the greatest of the entire project - digging two tunnels beneath Sydney Harbour.