The objective of the SMP4 project was to excavate the most critical area of the route and validate the overall feasibility of the project. It was in the “productive coalfield”, a very heterogeneous geological area, converging (1 m in diameter) and under great cover (600 m deep) that the teams managed to excavate 9 km in the tunnel and 3 km using the traditional method, safely mechanically or explosively.

Relive with our teams the highlights of this memorable day : our video.