The double red arrow "Churchill-Pfeil" from 1939, RAe 4/8 # 1021 of the SBB, seems tiny when crossing the highest railway viaduct in Switzerland, the 99 meter high Sitter viaduct of the former Bodensee-Toggenburg Bahn (BT) on the line from St.Gallen to Wattwil. The 365 meter long viaduct with a half parabola girder was erected in 1910 and has a main span of 120 meter.