I’ve posted before about my love of vintage dive watches, and today I thought I’d write a short post about one of my favourites, and possibly one of the most unusual dive watches in my collection. This is my Omega Seamaster 120 f300Hz which dates to 1972 – a watch produced with a tuning fork movement.
The first electronic watches were produced (by Elgin and Lip) in 1952. At the launch they were heralded as the greatest advancement in horology in 450 years, but they still used a conventional balance wheel movement and so offered no real improvement in accuracy over a hand wound mechanical movement. That same year however the Swiss watch company Bulova launched a project to develop an electronic watch that would take a leap forward in accuracy. Physicist Max Hetzel led the project to create the Bulova Accutron (the name taken from the words Accu racy and Elec tron ic), a watch that would not need to be wound and would be guaranteed accurate to within 2 seconds a day.
Hetzel came up with the revolutionary idea of using a tuning fork instead of a balance wheel. The tuning fork would be driven by a solenoid powered by a one transistor oscillator circuit, and was attached to a simple ratchet system which turned an index wheel one tooth forward each cycle. The first prototype was produced in 1955, and in 1959 the Accutron 214 was launched. It was the first wristwatch to employ a transistor, it made a strange humming sound, and was very accurate (in fact Bulova were so confident about its time keeping that they produced the watches without a crown on the side of the case, so the setting of the time had to be done by taking the watch off the wrist).
As well as producing a range of watches with this technology, Bulova also offered it to other manufacturers under license. One such manufacturer to embrace this technology was Omega, and during the 1970’s Omega released many watches based on the ESA 9162 (date only) and ESA 9164 (day & date) tuning fork movements. Omega, like many other manufacturers, allocated their own calibre numbers to the movements, so the ESA 9162 became Omega cal. 1250, and the ESA 9164 became Omega cal. 1260. Both movements contained tuning forks that vibrate at a frequency of 300Hz, hence these watches are known as f300’s. The photo below shows an Omega cal. 1250 movement in a Seamaster 120 f300Hz case – the photograph has been used with the kind permission of Paul Wirdnam of Electric Watches.
As a result of the huge advances in technology that were happening in the 1970’s tuning fork watches were only produced for a relatively short time. Quartz watches appeared in the early 1970’s and by the end of the decade more quartz watches were being sold than mechanical watches. This resulted in a crisis in the Swiss watch industry, and many Swiss watch companies became insolvent and went out of business as a result. By the end of the 1970’s tuning fork watches were no longer produced, but during the 17 years or so they were in production they were the most accurate production timepieces available and they remain an important step in horological history.
But as well as being important historically these watches are really rather cool in my opinion. The styling of these watches was quite different to the run of the mill mechanical watches of the period, and the tuning fork means that the seconds hand sweeps in a smooth continuous arc around the dial. Another aspect of the watch that I adore is that the tuning fork emits an audible hum as it powers the watch (as a result they are often referred to as “hummers”). I’ve owned many tuning fork watches by many manufacturers over the years, but my favourite is this Omega Seamaster 120 without doubt. The watch is 41mm diameter, so large enough for me to wear on my 8″ wrist without looking small, and although almost 45 years old it still keeps excellent time gaining around 2 seconds a week. It is one watch that I will never sell, and still wear regularly.
If anyone is interested in reading more about tuning fork watches, and electric watches in general, then I can recommend Paul’s website Electric Watches highly. Paul’s been collecting electronic watches for many years and has built up a huge collection and a wealth of knowledge in that time.