Riggenbach cog railway system. 19th-century artwork of a locomotive on a cog railway based on the Riggenbach system. This cog (or rack) railway system was invented by Swiss engineer Niklaus Riggenbach (1817-1899). Cog railways are used in steep mountain areas where a third toothed rail meshes with cogs on a train and its locomotive to support them as they ascend the incline. One such cog is seen under this locomotive at centre. Riggenbach was granted a patent for his system in 1863, and the first mountain railway using it opened in 1871. This wood engraving dates from circa 1888.