The tunnel boring machines carry out both the excavation of the subsoil, the support of the land crossed and the actual construction of the tunnel. They operate 24 hours a day, 6 days a week.
You can follow their progress from an interactive map on the website of the Line 14 extension project.
The position of each tunnel boring machine is updated every two weeks in order to show sufficient progress, i.e. about 150 metres at an average rate of 12 metres per day. A counter indicates the number of metres of tunnels dug out of the 5800 planned in total.