The training of underground workers trains professionals capable of intervening in the construction, maintenance and security of underground infrastructure such as tunnels, galleries, wells, sewers, or even mines. These specialized workers work in complex environments, sometimes confined, where the requirements for safety, precision and robustness are particularly high.

During this training, the learners develop solid skills in drilling, wall support, soil stabilization, laying of coatings, and handling of heavy machinery (such as drills, tunneling, lifting equipment). They also learn how to read technical plans, manage ventilation and drainage, and strictly apply underground safety standards.

Following the dual German model, this training typically lasts three years and alternates between professional center courses and on-the-ground experience. She offers students a direct introduction to the working world and is compensated from the first year. Once trained, souterrain workers can join large public construction projects (such as subways, railroad tunnels, and central stations), infrastructure projects, or businesses that specialize in foundation and subsurface work.