The tunnel boring machine in Airolo is ready for use
The official green light for excavation of the Gotthard South access tunnel (lot 343) took place with a special ceremony in Airolo on June 9, 2022. The cutting wheel of the pink tunnel boring machine was still symbolically turning in front of the portal on this festive occasion. It will soon carry out its work inside the launch tube, drilling some 5 km to the north.
The experienced assembly crew took over the disassembled TBM at the installation site in Airolo. It took weeks to reassemble and repair, and is now ready for operation.
“The tunnel boring machine, with its unusual color, already drew a lot of attention at the manufacturing plant in Schwanau, Germany. Whenever an employee or visitor walked past the machine, they would invariably stop to take a picture.”
The TBM has now moved forward through the 80 m long launch tube to the rock and is being equipped with the remaining trailing elements. This launch tube was driven in granular soil for geological and constructional reasons. The geology found there has proven extremely difficult. This is why seven of the eight originally planned pipe arch stages had to be secured using the more complex jet grouting process.
Starting in the summer, the TBM will head north to a fault zone, the “Guspis zone,” about 5 km from the portal in Airolo. This fault zone will later be crossed and secured through the main lot 341. This ensures that the large TBM (12.6 m in diameter) required for the road tunnel can pass through this area without any complications. Once the road tunnel is completed, this access tunnel will be used as a ventilation and drainage tunnel during operation.
- Lot 343 Access Tunnel Gotthard South is a subproject of the second tube of the Gotthard Road Tunnel (2TG).
- The diameter of the TBM is 7.4 m
- The machine has a total length of 175 m and a total weight of around 1,110 t