1920 –

In connection with electrification, the old telegraphic overhead lines were replaced with telecommunication cables in the track bed. At the same time, telephone posts were set up along the line.

The track telephone was the first telephone system to come into general use along the line. It was used between stations and railway personnel to convey messages about changes in train times, extra trains, and more.

Originally, there were track telephones intended to be connected to the overhead lines. However, when these were replaced by telecommunication cables in the track bed, telephone posts were set up every 2-4 kilometres along the line. Through these posts, train and railway personnel could receive information about what was happening further along the line. Likewise, they had the opportunity to quickly raise an alarm if something happened that required the traffic to stop.

The telephone was brought on board the train or the trolley and plugged in when needed to make a call. Today, telephone posts have largely been replaced by fixed telephones and, above all, various types of radio communications.