Breakthrough

摘要

Breakthrough was made on the Gotthard base tunnel under the Swiss Alps on 15 October. The 57km rail tunnel is the world's longest.Drilling from the Faido section in the east tunnel, a TBM broke through the last metre of rock on the route to Sedrun. The location was 30km from the north portal and 27km from the south portal.AlpTransit said the tunnel breakthrough was highly accurate. "At 8cm horizontally and 1cm vertically, the deviation was very small."About 200 people witnessed the breakthrough, and around 3,500 miners, engineers, surveyors and others watched on big screens at other locations nearby.