Dual electrification

A commuter train at a station. Below the train, four rails are visible—two are for the wheels and one provides power. Above the train, a catenary power line is also visible.
This photo shows an overhead catenary power line above the foreground train, and a third rail on the ground beside it.

Dual electrification is a system whereby a railway line is supplied power both via overhead catenary and a third rail. This is done to enable trains that use either system of power to share the same railway line, for example in the case of mainline and suburban trains (as used at Hamburg S-Bahn between 1940 and 1955).[1]

  1. ^ "Archived copy" (PDF). Archived from the original (PDF) on 2017-08-08. Retrieved 2017-08-08.{{cite web}}: CS1 maint: archived copy as title (link)