From the archive:


These days, most of us take the concept of synchronised time for granted. When it’s midday in Sydney, it’s also midday in Canberra.

But not that long ago time was calculated by the angle of the sun. So it varied from region to region. 

These small local differences in time were not a problem until the introduction of railways, which needed an accurate and coordinated time-keeping system to operate reliably and safely. People needed to know when trains were arriving and departing.

So, with the expansion of railways came the rollout of standardised time across the state, through thousands of watches, clocks and other time-keeping devices located on platforms, in offices, workshops, parcels rooms and signal boxes.

The greatest breakthrough was the impulse system, which was introduced after the rail network was electrified in the 1920s. It allowed every clock on every station, within a given area, to carry the same time. 

The system worked via an electrical impulse that was sent every 30 seconds from a precise ‘master’ clock to connected ‘slave’ clocks within a particular area. There were 14 of these master clocks across the state, each controlling a set of slave clocks within their area, with the impulses moving the hands of every slave clock simultaneously.

  • A group of people sitting on a bench at central station in front of an board showing train destinations
  • A close up of the clock face at Central station in Sydney
  • A view of the clock tower at central station under construction in 1919
  • Black and white architectural plans from 1920 for Sydney’s new central station
  • An expansive view of the central station concourse in 1906
  • A view of the main concourse of central station circa 1986

The standardisation of time also created new jobs. There were dedicated clock mechanics to maintain and repair the clocks. There were even clock winders, who would ride the mail trains, and hop off at each station to wind the clocks, carry out repairs and polish the brasswork. 

And at the Central Station clock tower, two people were employed just to keep the giant clock going.

But some of these jobs started to be wound back with the introduction of digital and quartz mechanisms in the 1970s. 

Our time-keeping now uses a satellite-based system, which was introduced for the 2000 Sydney Olympics. It might take the romance out of our time-keeping, but it means it is accurate to the second. 


  • Dr Bradfield made the City Circle Stations and subway finishes ‘colour coded’. Museum has a course of red tiles, St James’ are green, Wynyard’s are blue and Town Hall has yellow tiles, with only remnants of the earlier schemes remaining at these two sites.
  • When Wynyard Station was built, many people would travel to the city just to ride the escalators.
  • During World War II, the unfinished tunnels planned for a future extension to the Eastern Suburbs of Sydney were set up as air raid shelters, and the tunnel from St James to Circular Quay was used by the military as a secure command point.
  • An underground line to the Eastern Suburbs Line was not built until the late 1970s, and opened in 1979, but on a different route to the one Bradfield had planned and had made a substantial start on constructing in the 1920s.