BDhe 4/4 power car 121 of the Wengernalpbahn descends from Kleine Scheidegg to Wengernalp on 20 March 2002. These power cars of the second series are mostly in duty with new lowfloor articulated trailers, so they have a new livery. In this case the train contains an old trailer, normaly used with power cars of the first BDhe 4/4 series, and a freight car for the skis. Note the two coloured lights above the left headlight. Unlike at big railways, several trains run together in a fleet here, following eachother on sight. As far as I know, different rearlight colours are used to indicate if a train is the last one of the fleet or if others will follow.
Digital photo by Christoph Schmitz