The construction site is located close to the Spullersee, one of the most impressive mountainsides in the Alps, and is part of the ÖBB Spullersee power station, which is used to generate green 16.7 Hz traction current. The Spullersee, a formerly natural mountain lake, is located over 1800 m a.s.l.in the municipality of Dalaas in Vorarlberg. After almost a century of generating electricity, essential parts of the plant have reached the end of service life, resulted in essential facility renewals as well as numerous operational optimizations in the last two years. In a first construction phase, a new access tunnel to the existing apparatus chamber had to be excavated before seasonal winter closure of the access road. For the winter construction phase, thousands of tons of building materials were stored on the construction site in order to replace the old system parts in the area of the lake‐side apparatus chamber after the Spullersee had been completely emptied. Due to high‐alpine location of the site in one of the snowiest regions in Austria, not just working in winter was challenging, but also access. In winter the site was achieved only by using a small cable car and a narrow footpath through the almost two‐kilometer‐long pipe tunnel. This was not everyone's cup of tea.