The clock is the brainchild of Hans Hilfiker, an engineer with the Federal Railways, and was used for the first time in 1944. The timepiece remains eye-catching 75 years on.
Hilfiker was inspired by the Bauhaus movement, a German art school noted for a synthesising technology, craftsmanship and design aesthetics.
Instead of numbers, the clock face shows simple vertical lines as indicators and a rotating red second hand reminiscent of the traditional signalling disc of the station masters.
Despite its age the design looks as young and fresh as ever. It served as a model for the clocks on the tablet computers which Apple introduced in 2012.
In a bid to avert a legal dispute, Apple agreed to pay CHF20 million ($20.1 million) to the Swiss national railway company in exchange for the rights to use the clock design. It disappeared from iPads soon afterwards, when Apple released its iOS 7 mobile operating system in 2013.