It will be the world’s longest railway tunnel: the Gotthard base tunnel has been driven through 57 km of mountain mass in Switzerland, to connect Erstfeld in the Canton of Uri with Bodio in the Canton Ticino. Its goal is to speed up passenger transport and to ease freight transport. The first blasting of the tunnel was in 1999; the commissioning is at present planned for the end of 2016. To ensure as much safety as possible with the intended high capacity use, alkitronic®’s electric torque multiplier EFCip was used for construction of the tracks.
The building contractor of the Gotthard base tunnel is the AlpTransit Gotthard AG, a subsidiary of the Schweizerische Bundesbahnen (SBB). In May 2007 they assigned the Arbeitsgemeinschaft (ARGE) Transtec Gotthard the order to equip two one track tunnel tubes as well as the following sections north and south to the existing railway system. 200 employees installed the railway and in October 2014 the last bolts were tightened on the track bed. Already at the end of 2015 and the beginning of 2016, the first test service runs were scheduled to go through the complete tunnel. The wagons will travel as fast as 220 km/h.
Especially freight transport will benefit from the new Gotthard base tunnel after its completion in 2016. According to plan, the new section will be used daily by 220 to 260 trains. The major part will be freight transport. This way transport capacity on the route can be increased from 20 to nearly 50 million tons each year. Passenger trains will cross the 57 km at a max. speed of 250 km/h, reducing travel time between Zurich and Milan to 160 min. Currently as many as 180 trains have to use the route over the mountain every day. This is only accomplished with less weight and the help of a second engine. The new tunnel is nearly ground-levelled – its highest point is 550 m above sea level, which is not much higher than the city of Munich. However, precise planning and execution are necessary.
Quality and accuracy during installation are a top priority to ensure the safety of trains and passengers in the tunnel tubes.
“Quality and accuracy – these are our cues”, explains Bruno Stoll, employee at alki TECHNIK GmbH. For more than 30 years the Bavarian company has been producing bolting systems with electric, hydraulic, pneumatic and manual drive. At the track-laying construction in the Gotthard base tunnel, three electric torque multipliers alkitronic® EFCip have been in continuous operation since May 2012: “The high robustness, ensured by compact design and cast aluminium housing of the EFC motor, makes the EFCip an ideal tool on the vast building site in the Gotthard base tunnel,” says Stoll.
Further advantages are the high repeat accuracy of ± 3% and the low-noise operation. For both tunnel tubes there was a total of 114 km of track work, where approx. 1.000 000 boltings were carried out. In the first step the track sleepers on the track system were automatically raised and fixed to the rails from below. The two bolts on the side were loosened and the two clamps placed over the rail base. Finally bolting was made on both sides. In the past a standard impact wrench was used for tightening and a torque wrench for retightening.
“With the alkitronic EFCip the three work steps of tightening, retightening and examination were carried out in one single work step due to the pre-adjustable torque of 160 Nm and automatic shut-off” – Georg Jaffke, construction manager at ARGE Transtec Gotthard tunnel, was most satisfied with the torque multipliers: “We were very impressed with the saved work-time, and also the accuracy of the alkitronic torque multipliers. We can only recommend the tools.” In this way 31 m of track per hour were laid through the Swiss mountains – almost with Swiss clockwork precision.