The Brienz Rothorn Bahn (BRB) is an gauge tourist rack railway in Switzerland, which climbs from Brienz, at the eastern end of Lake Brienz, to the summit of the Brienzer Rothorn mountain. The two designers, engineer Alexander Lindner and contractor Theo Bertschinger were supported by the mountain railway pioneer Roman Abt, who had responsibility for equipping the line with his newly developed double lamella rack system.