BBC 2’s Fifteen Billion Pound Railway starts on 16 July at 9pm and follows work on the new train tunnels and stations under London.

Crossrail provided exclusive access over two years to the BBC’s producers Windfall Films who spent time with tunnellers and engineers as construction of the new railway progressed.

They witnessed the engineering challenges and key milestones including the spectacular tunnel machine breakthroughs.

Crossrail Chief Executive Andrew Wolstenholme said: “The documentary series provides a unique insight into the complexity and challenges of delivering Europe’s biggest construction project through the very heart of London.

“Every day people walk past our construction sites unaware of the maze of tunnels that are being constructed below London’s busy streets.”

One of the stars of the documentary is western tunnels and stations Project Manager Andy Alder.

He said:: “We think our work is pretty exciting. This documentary is a chance for the public to come into our subterranean world and see how we build big tunnels using massive machines, while preserving London’s archaeological history and making sure London keeps moving.”

The first episode, Urban Heart Surgery, follows the team of workers as they drive 1,000-tonne tunnel boring machine, Ada, through Tottenham Court Road station within 800mm of the operating Northern line.

It also looks at how Crossrail has ensured Bonhams auction house in Mayfair is able to receive its vintage cars for auction.

Episode two, Tunnels Under the Thames, sees the Bermingham father and son team follow in the tradition of tunneling greats, the Brunels, and build new train tunnels under the River Thames in southeast London.

Meanwhile, Project Manager Linda Miller is rebuilding the Victorian Connaught Tunnel under the Royal Docks.

The final episode, Platforms and Plague Pits, tracks the team as they construct the cathedral-sized new station at Canary Wharf.

The cameras join engineers as they carve out the underground caverns that will become the new stations at Liverpool Street and Whitechapel.

And, it follows archaeologists as they uncover a 14th Century emergency burial ground, established ahead of the plague.

For a sneak preview of the series click here