TBM

TBM

The excavation of the tunnel for the Torino Automatic Subway was carried out mainly with a TBM (Tunnel Boring Machine), the so-called "Mole", a large drill that excavated under corso Francia between 2002 and 2005 and under via Nizza from 29 February 2008 and 23 September

2009. In total, 4 TBMs were used: three to excavate the stretch from Collegno to the station of Porta Nuova (named Valentina, Madama Cristina, and Valeria) and one (named Caterina) to excavate between the stations of Marconi and Lingotto.

La Talpa (The Mole)

About 80 metres long and 8 metres tall, this equipment is transported to Torino disassembled into individual elements; once they are lowered into the Marconi station, they are then reassembled underground. The excavation is carried out about 20 metres underground without interfering with the utilities grid (installed at a lesser depth). The TBM enables the excavation of long stretches of tunnel while dust and noise remain underground, thereby minimising the inconveniences and disturbance associated with the construction site on the surface. Following the passage of the TBM, the gallery is ready for finishing operations and installation of safety systems; this phase will last about 10 months. The TBM is indeed a mobile construction site that advances at a speed of 10 metres a day, fully self-equipped for the excavation, the disposal of debris, and the finishing of the tunnel.