Swiss project sets new world record
The Gotthard base tunnel finally broke through at a depth of some 2 000 m on Friday, 15 October 2010. At 57 kilometres it is currently the longest rail tunnel in the world. The event, which was acclaimed internationally as an engineering masterpiece and an unprecedented achievement, was also an impressive demonstration of how engineers, mining teams and geologists – and governments and people too – could work effectively together. AlpTransit Gotthard AG is the principal developer of the new NEAT rail link (Neue Eisenbahn Alpentransversale) at the Gotthard. Thyssen Schachtbau GmbH was also involved in the project, carrying out shaft sinking, drilling and logistics work during the tunnel construction phase.
The Gotthard base tunnel is the centrepiece of the AlpTransit Project that has driven a new route through the Gotthard massif. The 57 km-long tunnel consists of two parallel single-track tubes that are linked every 312.5 m by a series of connecting galleries. The tunnel starts off at Erstfeld and follows a slightly curved line towards Biasca, thereby connecting the two part-sections of Uri and Riviera.
The Erstfeld portal is sited on the northern side of the Alps, while the Bodio portal is on the south side. The tunnel is divided into three sections of almost equal length by the two multifunction stations (MFS) of Sedrun and Faido. These two MFS consist of large underground chambers that house the technical infrastructure and equipment needed for the railway operations and will also serve as emergency stopping stations that provide a link between the east and west tubes.
When this impressive engineering project is completed it is expected that some 30 000 passenger trains and 77 400 goods trains will make the journey through the two tunnel tubes every year. The first trains are scheduled to pass through the tunnel in December 2016. The breakthrough to link up the final two sections of tunnel is a transport milestone for Switzerland and the whole of Europe. The section from Erstfeld to Bodio will cut the journey time from Zurich to Milan by 60 minutes to a mere 2.5 hours. Inside the tunnel the trains will travel at a maximum speed of 250 km/h.
The breakthrough is broadcast live around the world
The major event of the tunnel breakthrough was broadcast live in many countries. The 9.5 m-high and 400 m-long tunnel boring machine cut through the last 1.8 m of rock between the Faido and Sedrun sections at about 14.00 hrs on 15 October 2010. The little town of Sedrun, in the heart of the Alps, was at that moment the centre of the world.
Swiss-based Implenia Bau AG – a major construction company that played a significant role in the tunnelling operation – provided the technical leadership for three of the five part-sections. In 2002 Implenia Bau AG and Thyssen Schachtbau GmbH set up the permanent joint venture TIMDRILLING with a view to collaborating in major construction projects – with the Gotthard base tunnel very much in mind. The main services offered by the partnership include:
- Preventer supported rotary percussive and core drilling operations for exploratory survey work in tunnel construction projects
- Rotary percussive and core drilling without a pressure closure device
- Conventional and mechanised shaft sinking, especially for tunnel and hydro-electric construction projects
- Transport of construction materials and heavy items
- Installation and operation of vertical and inclined shaft winding systems
- Installation of infrastructure and supply lines for tunnel construction projects
- Injection work for strata sealing and reinforcement
- Raise boring
- Ground freezing
TIMDRILLING will continue to provide specialist services for clients after the Gotthard base tunnel project comes to an end in late 2016. With the expected increase in infrastructure projects and pumped storage schemes there will be no shortage of demand for competent providers of construction and engineering services in the years ahead.