After completing its initial 2,539-meter drive, the Tunnel Boring Machine (TBM) had to be dismantled at its arrival station, Ponts Jumeaux, and reassembled at its new departure station, La Vache - Le Grand Marché, to excavate the final 2,122-meter tunnel section toward Raisin station. To accomplish this, our teams orchestrated a major logistical operation, carried out in two key phases.

Surface Transfer of the Shield: An Exceptional Convoy

The TBM's shield and its cutterhead—a centerpiece weighing nearly 150 tons with a 9.67-meter diameter—were transported vertically. The components were moved overland by special convoys between the two stations at a speed of 3 km/h under escort.

Rotating the Gantries: An Underground Tetris Game

Meanwhile, a complex logistical sequence was coordinated inside the tunnel. The TBM's five gantries (backup trailers) were moved backward between the Ponts Jumeaux and Fondeyre stations. Then, within a very confined space, they were turned one by one and reordered in the correct direction of travel before being reconnected to the shield at the La Vache - Le Grand Marché station.

Next step: excavating the 2,122-meter section between La Vache and Raisin stations. The underground adventure continues!

Joint Venture: Eiffage Génie Civil (lead partner) / NGE - BTP

Client: Tisséo Ingénierie - Tisséo Collectivités

Credit: MXR Communication - specialists in construction industry communication.