Lyon-Turin line progresses on 11 fronts

The Herrenknecht machine will be operated by the Italian-French group CO 6-7, which comprises a French-Italian group of companies comprising Vinci Construction, Webuild, Dodin Campenon Bernard and Campenon Bernard Centre Est on the Lyon-Turin line.

The TBM is 180m long and has a 10.4m diameter. It will excavate the 9km of the north tube, alongside the work already completed on the south tube, between Saint-Martin-La-Porte and La Praz.

The first Herrenknecht TBM for CO 6-7 passed its FAT in July. It will dig one of the two tunnel tubes between La Praz and Modane.

Each TBM has 8,100kW of power, weighs 2,300 tons and is equipped with 61 cutters.

Tunnel Euralpin Lyon-Turin (TELT) says work on the rail line is progressing on 11 fronts.

In September 12.5km of the 57.5km tunnel had been dug and the second of four 500m-deep ventilation shafts was completed in the Avrieux area.

On the Saint-Julien-Montdenis construction site, excavation with the traditional method is progressing. On the Saint-Martin-la-Porte platform, the consolidation of the entrance face of the West Logistics Tunnel and the excavation of the second logistics tunnel continues, while the construction of the first part of the large technical cavern transverse to the foot of the descent has almost reached 50m. In the meantime, the shaping of the descent has been completed in La Praz.

For this construction site between Saint-Martin-la-Porte/La Praz and Modane, the arrival of the three TBMs this section in both directions is awaited. The first two TBMs were delivered to the factory between July and early October, while the third will be delivered in mid-November.

Towards the Italian border, at the foot of the Villarodin-Bourget/Modane descent, three traditional advance fronts are active to create the technical caverns for the assembly of the TBMs or logistics.

On the surface, excavation of the road tunnel is under way. This is part of the new Modane ring road which will allow construction vehicles to bypass the city centre.

Meanwhile TELT has awarded a contract for the recovery of excavation materials on the French side of the Mont Cenis tunnel (works package CO11) to a consortium comprising Vinci Construction subsidiaries Eurovia Alpes, Carrières du Bassin Rhônalpin, and Terélian; VICAT subsidiaries SATM and Granulats Vicat; and Spie Batignolles Valérian, Spie Batignolles Malet and GIE GMM 73.

The €800m (£694m) contract covers industrial processing of the 23 million tonnes of materials excavated on the French side with a circular approach, including reuse of over 50% of the spoil on site.

The complex will include three permanent storage sites, three materials processing stations, eight logistics platforms, 15km of conveyor belts and a full train loading facility.

Once completed, the 57.5km Mont Cenis base tunnel – 12.5km in Italy and 45km in France – will be one of the longest rail tunnels in the world.