The London tunnels programme of Britain’s high-speed rail project, HS2, has marked a notable milestone. The project to build a new railway between London and Birmingham has launched a third tunnel boring machine (TBM) beneath the capital. The TBM, named Emily, weighing around 1,700 tonnes, has commenced its excavation journey, undertaking a 3.4-mile (5440-metre) dig under the north western suburbs of the city.