The story of Crossrail told through the eyes of the men and women facing the world?s most ambitious engineering challenge.

This series follows a team of more than ten thousand engineers and construction workers close up - as they race to build a brand new subterranean railway under London Crossrail Londons new Underground. Costing almost fifteen billion pounds and taking ten years to build, its the biggest engineering project in Europe. The challenges facing the team are immense from digging out forty-two kilometers of tunnels to constructing ten vast new stations all while keeping London moving. Episode 1: Urban Heart Surgery Building a brand new underground railway is never easy, but building one underneath the streets of one of the worlds biggest and busiest cities is especially tough. The engineers building Londons new underground Crossrail have to make sure that listed buildings dont crack, the tubes keep running, the City stays in business and that a consignment of priceless vintage cars doesnt fall down a grout shaft in Mayfair. Most dramatically, they must drive one of their gigantic 1000-tonne tunnel boring machines through a tiny gap in the congested underbelly of Tottenham Court Road station without the passengers on the platforms below knowing they are there. Episode 2: Tunnels under the Thames In this second instalment of the three-part series, the engineers building Londons brand new underground railway, Crossrail must take on a Great British obsession building train tunnels under water. Linda Miller, an American engineer more used to building space launch complexes at Cape Canaveral, finds rebuilding a Victorian tunnel under the Royal Docks in Londons east end more complicated than originally thought. A British tunnelling dynasty the Berminghams follow in the footsteps of the original father-son team of Marc and Isambard Kingdom Brunel to build the latest tunnel under the river Thames, and a young engineer goes through an important rite of passage. Episode 3: Platforms and Plague Pits Building the UKs newest underground railway is a big job: its big money, big trains and it needs big stations. In this final part of the three-part series, engineers must put together the giant jigsaw that will become a cathedral-sized station at Canary Wharf. Its so big they have to build it in a dock and underwater. Its architect-designed roof is so complicated it comes in a kit of over 2500 pieces. As engineers carve out the underground caverns that will become the new stations, they hit on some gruesome discoveries of Londons past.