One of my prefered location on the Gotthard mountain line, you may remember https://www.railpictures.net/photo/221930/ , one of my first picture on Railpictures, 13 years ago. "Traverso" train RABe 526 # 107/207 of the Südostbahn (SOB), built by StadlerRail, running as Interregio 2430 of the line IR 46 "Treno Gottardo" from Locarno over the Gotthard mountain line, is leaving the Wattinger loop tunnel and crossing the 38 meter long lower Wattinger bridge over the Reuss river. The concrete bridge, cladded with local granite stones, was new built in 1954, before it had been a truss bridge. The Südostbahn is running this trains over the Gotthard mountain line between Basel/Zürich and Locarno on behalf of the SBB since december 2020, and they are a remarkable sucess. The Reuss has more water then normal, but some days ago there was high flood. Most of the water in this course of the river is used by the hydro power station Wasser, and is not visible here.
