In Switzerland the Swiss railway clock was designed in 1944 by Hans Hilfiker, a Swiss engineer, together with Mobatime, a clock manufacturer, for use by the Swiss Federal Railways as a station clock. In 1953, Hilfiker added a red second hand in the shape of a railway guard’s signaling disc.
The clock owes its technology to the particular requirements of operating a railway. First, railway timetables do not list seconds; trains in Switzerland always leave the station on the full minute. Secondly, all the clocks at a railway station have to run synchronously in order to show reliable time for both passengers and railway personnel anywhere on or around the station.
The station clocks in Switzerland are synchronized by receiving an electrical impulse from a central master clock at each full minute, advancing the minute hand by one minute. The second hand is driven by an electrical motor independent of the master clock. It requires only about 58.5 seconds to circle the face, then the hand pauses briefly at the top of the clock. It starts a new rotation as soon as it receives the next minute impulse from the master clock.