Cog Railway Tracks With An Additional Toothed Rack Located In The Middle Of The Track To Overcome Large Tilts. Royalty-Free Stock Image

A rack railway also rack-and-pinion railway, cog railway, or cogwheel railway is a steep grade 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 10%, which is the maximum for friction-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.