Channel Tunnel (1988-1994)
Eleven tunnel boring machines drove about 150 km of tunnels linking Britain and France beneath the English Channel, with the first undersea breakthrough in 1990. The rail tunnel opened in May 1994, roughly a year and a half behind schedule.
The tunnel opened in 1994 and became the fixed rail link between the two countries.
The project ran billions over budget and years late, yet has carried passengers and freight for three decades.
Shows how multi-year TBM excavation precedes decades of service, and how even megaproject schedules stretch.
