The station master was responsible for ensuring that everything in the railway station area worked. This included the functioning of the signals, maintenance of the station clock, and responsibility for the trains arriving to and departing from the station. The station master was also responsible for ensuring that the orders and instructions from the traffic director were communicated to the other traffic staff at the station.

The station master had the authority to delegate responsibility, and this was often the case for the arrival and departure of trains. It is sometimes said that the station master waved the trains off, and he did. But in most cases it was actually an official under the station master who did this.

Others in charge of railway stations, often at smaller stations, were assistant station masters.
At transport hubs that were classified as stops rather than stations, there were train arrival/departure signallers (platsvakt), many of whom were women.  

Station master at the Ångfärjestation (steam ferry station) in Trelleborg, 1930s.