FerroCarril Trasandino de Chile (FCTC, Chilean Transandean Railway)
Rack railway locomotive built by Kitson & co. 0-8-6-0cog configuratio
A rack-and-pinion railway (also rack railway, cog railway) is a railway with a toothed rack rail, usually between the running rails. The trains are fitted with one or more cog wheels or pinions that mesh with this rack rail. This allows the trains to operate on steep grades above 7%, which is the maximum for adhesion-based rail. Most rack railways are mountain railways, although a few are transit railways or tramways built to overcome a steep gradient in an urban environment.