"Round the Säntis" charter trip of RAe 4/8 # 1021 "Churchill-Pfeil" (Churchill Arrow) is crossing the 282 meter long Weissenbach viaduct on the former Bodensee-Toggenburg Bahn (now Südostbahn) line from St.Gallen to Wattwil. The 56 meter high viaduct was built in 1910.