A look at London's Crossrail, which requires building 42 km of tunnels under the city

Engineers building Crossrail battle to rebuild a Victorian tunnel under the Royal Docks.

The engineers building Crossrail race to build ten new train stations across London.

Linda and her team must battle fault lines that threaten the site with flooding, race to build access tunnels to alleviate pressure on a congested construction site, and piece together a giant geometric jigsaw that will form a station entrance.

Engineers must construct and fit out a new station at Paddington, erect a 130m long great glass canopy to soar above the structure, and plug directly into Brunel's original station.

The first part of an exclusive series following the construction of Crossrail - one of Europe’s largest projects and one of the most ambitious in Britain since the time of Brunel.

Final part of an exclusive series following the construction of Crossrail - one of Europe’s largest projects and one of the most ambitious in Britain since the time of Brunel.

With exclusive access to Crossrail Ltd and Transport for London, this final chapter of the series follows the race to fix the railway's high-tech software and systems to launch the new Elizabeth Line in time for the Queen's platinum jubilee.

We follow 83-year-old site manager Jim Forrest - one of the oldest engineers on the project. He joined the Whitechapel Station build in 2009 and has seen it from tunnel boring and concrete pouring to constructing the station steel works.