Both units in Melbourne and Sydney were run in tandem (primary and backup).
For daylight saving time changes, one would be on line while the second was advanced or delayed by one hour and at the 02:00:00 Australian Eastern Standard time, would be switched over to the standby unit.
As well as the speaking clocks, there was ancillary equipment to provide timing signals, 1 pulse per second, 8 pulses per minute and 8 pulses per hour.
The Time and Frequency Standards Section of the PMG Research Laboratories at 59 Little Collins Street, Melbourne maintained frequency checks to ensure that the system was “on time”.
From a maintenance point of view, the most important thing was to ensure the clocks remained well oiled to minimise wear on the cams and to replace blown bulbs in the optical pickups from the glass disk recordings.
When Time & Frequency Standards moved to Clayton Research Labs, the control signals were duplicated and a second bank of Caesium Beam Primary standards installed so the cut over was transparent with no loss of service.
This mechanical system was replaced with a digital system in 1990.
The voice was provided by Richard Peach, a former ABC broadcaster.
Peach, who died in 2008, was a Gippsland radio breakfast announcer and station manager during the early 1990s.
He was known to Gippsland audiences before that for his role as presenter on the Victorian regional afternoon program.
Each speaking clock ensemble consisted of two announcing units (Zag 500), a supervisory unit (CCU 500), two phase-locked oscillators, two pulse distribution units, a Civil Time Receiver (plus a spare), and two or four Computime 1200 baud modems.
The various components were sent for commercial production after a working prototype was built in the Telstra Research Laboratory (TRL).
Assmann Australia used a German announcing unit and built a supervisory unit to TRL specifications.
The changeover occurred at 11:59:52, September 12, 1990.
Each state capital had a digital speaking clock for the local time of day, with one access number for all Australia — 1194.
In 2002, the 1194 service migrated to Informatel, which used its own digital technology, in conjunction with the National Measurement Institute — but kept the original voice of Richard Peach.
The other time services such as hourly pips to radio stations were retained as a service by Telstra.
In May 2006, the remaining Telstra services were withdrawn and the digital hardware was decommissioned.
The serviced was finally turned off the service at the midnight on September 30, 2019.