Re 620 # 076 and Re 420 # 290 in multiple control, also called "Re 10/10", are pulling the empty excavation train 67653 from Flüelen over the Gotthard mountain line to Ambri-Piotta. The hydropower station Ritom of the SBB, dating from the electrification of the Gotthard line in 1920, is undergoing a large rebuilding to a new pumped storage hydro power station with increased capacity. For this purpose, a 100'000 m3 storage basin has to be excavated in Piotta. The material is transported from Ambri-Piotta to Flüelen and further by barge over the Vierwaldstättersee to the part of the lake which is called Alpnachersee. There it is used to fill up "holes" in the lake which resulted from the mining of gravel.