How Crossrail Was Bored Just 700 mm From a Tube Tunnel — Without Disturbing It

Crossrail: 42 kilometres of new tunnel driven under central London, past cast iron tube tunnels carrying passengers, without letting a single building above the route move. At Tottenham Court Road the new tunnel passed the Northern line with between 600 and 700 millimetres of London clay between them. The railway cost 18.8 billion pounds against a 14.8 billion budget set in 2010, used 8 machines cutting a 7.1 metre bore, and needed a further 14 kilometres of station caverns that no machine can produce. This documentary covers the full engineering and construction process, from the settlement trough that forms above every bored tunnel, to the monitoring regime that watched thousands of buildings continuously, the compensation grouting that fed material back into the clay in real time as the ground began to give, the sprayed concrete method used where a circular machine is useless, and the burial ground at Liverpool Street that sat on the critical path. Why differential settlement, not settlement, is what cracks a building. How engineers kept the tunnel face supported in saturated gravel under the Thames. Why the tunnelling finished on alignment and the project still ran 4 billion pounds over. What the 350 millimetre clearance figure circulating online cannot be stood up with. Subscribe to BRITAIN BUILT for the engineering behind the works that made this country, and the ones Britain built everywhere else. #Crossrail #Megaprojects #HowItsMade #London #ElizabethLine #Engineering #CivilEngineering #Construction #TunnelBoring #BritishEngineering #Underground #FullProcess #Infrastructure #Trending IMPORTANT: ABOUT THIS VIDEO This is an educational documentary analysing the engineering and construction of public infrastructure, based entirely on open-source information. All visuals and animations are 100% synthetic, AI-generated conceptual representations. No real footage of the construction sites or personnel was used. This video is purely informational and intended for educational purposes only.