Inception

1866. 154 years ago. Alfred Nobel invents dynamite. SS Great Britain lays the first transatlantic telegraph cable. Otto von Bismarck narrowly escapes assassination. Louis Francois Clement Breguet files patent number FR 73414 A.

Patent 73414 describes an electric pendulum clock using a tuning fork as the mechanical oscillator.

One prong on this 100 Hz tuning fork is free to move and the other moves within a pallet assembly acting on the escapement wheel. This design was fascinating and revolutionary for the time. It did suffer from a large amount of wear as it is not a free escapement and it was susceptible to inaccuracies.

The concepts used within this clock are the foundation of all tuning fork watches to follow. This concept was groundbreaking but it took more than Breguet to scale this technology down for use by the masses.

Max Hetzel

Born in 1921 Max Hetzel graduated from the Zurich Federal Polytechnic School as an electronic engineer. He joined the Bulova watch company in 1948. I can imagine his abilities were noted early on and his developments within Bulova led to the legendary Accutron movements. Between 1950 and 1959 Max worked as a development engineer. He was head of research in to automation problems of classical watch production. During this time he worked on around 20 patents.

His last position at Bulova was chief physicist at the headquarters in New York. In 1959 the Accutron movement is developed by Max and William O. Bennett.

Accutron – “Accu” for accuracy and “tron” for electronic.

The team had managed to reduce the number of parts to 27 of which only 12 were moving. In comparison a self winding watch of that period had over 130 parts of which 26 were moving.

The Accutron uses the tuning fork principle. These forks are magnetic – so when a current is applied to the tiny electromagnet coils it causes them to vibrate. Because tuning forks vibrate at a constant it is therefore possible to anticipate the frequency. This linear vibration is then transferred to a tiny index wheel 2.4 mm diameter with 320 teeth via two jewels – one stationary and one moving with the forks.

The initial concept for the Accutron movement can be seen in its most basic form as the 114. What’s notable about this earlier movement is the timing modulation at the very top of the case. “F | S” denoting fast and slow allowing the wearer to adjust the timing if desired. This text and function is removed on later models and instead added the regulators to the forks.

Accutron 114 P

Accutron 114

This prototype movement was never sold to the public making it incredibly rare. 100 models were produced for testing by Bulova executives. Back in 1960 one prototype – be it a 114 or earlier was lost by John F Budd Jr. At the time is was valued at $60,000 which in today’s values equates to in excess of half a million dollars.

Accutron 214

The Accutron 218 was released to the masses on October 25th 1960. It was originally available in steel, gold or platinum cases. Finally the brainchild of Hetzel was able to make it to the wrist of anyone who wanted pure unadulterated accuracy. Running from 1.35 volt power cell it claimed to be 99.9977% accurate – could you ask for more? If it fell out of the window they would adjust it for free in the first year of purchase.

Mechanical watches have their limitations. Accuracy has always been one of them. It’s quite easy to take our mobile phones and digital watches for granted with their impossible accuracies and no need for adjustment. Mass produced watches today have tolerances depending on manufacturer quality – these can range from +-30 seconds to +-5 seconds per day. In the field of aviation or space travel a few seconds drift can cause big differences.

If you’re travelling at a max speed of 4,520 mph in your new North American X-15 from 1961 – and you miscalculate by 5 seconds. How much distance have you just covered?

You will have just rocketed over an extra 6.3 miles in essentially a blink of the eye. As we started travelling faster we needed greater accuracy to coordinate and plan without flying over the mark. Why did I choose the X-15? Because all test pilots of this aircraft were issued with a Bulova Accutron 214 Astronaut. That’s some pretty hefty endorsement by NASA for what was basically brand new technology.

In 1969 these space age movements finally headed to where they were destined. The Accutron 214 powered the clock in the Apollo 11 space shuttle, the clock and timer on the Apollo Lunar Surface Experiments Package (ALSEP) and a large amount of satellites released into orbit in the 1960s. It’s clearly list in the 1967 ASLEP manual – providing an accurate time reading over a two year period.

So proud of their movement and this new technology, Bulova decided to display it for all to see. This completely exposed movement without a dial was called the Spaceview. It presented the tuning fork, coils, wiring and resistors for the world to marvel at – all on your wrist. The hour markers were either printed directly to the crystal or a chapter ring to improve legibility.

Another unusual change to the norm was positioning the crown on the underside of the watch. The battery cover and crown where hidden from view creating a much cleaner overall look. Changing the time consisted of pulling the d-ring up and turning to the desired position. In a normal mechanical watch this would be considered poor placement as changing and setting would become tiresomes – not so as the battery life and accuracy meant less fiddling.

Accutron 218

Max Hetzel parted ways with Blova in 1963. William Bennett took over spearheading tuning fork technology. Initially slight modifications and refinement occurred with the 214 movement – things like changing germanium transistor circuits to the more superior silicone items significantly reducing current draws at higher temperatures minimising the risk of premature power cell failure. It was clear that more could be done such as integrating complications such as day and date. The 214 had been time only and GMT since launch.

In 1965 Bulova released the 218 movement. This was marginally slimmer (4.4 mm vs 5.5 mm) and exhibited a more traditional side exit stem at 4 o’clock. Complications were added allowing the addition of a suffix on the 218 to denote changes.

• 2180 time only
• 2181 date only
• 2182 day and date
• 2183 time only – no seconds hand
• 2185 two time zones and date
• 2186 digital display

The 218 featured quick set date – turning the crown when fully in. It was also possible to use a modern 1.5 volt silver oxide battery with minor adjustment to the movement. Later models featured 3 different types of hacking; mechanical (2182), electrical (F) and full battery disconnect for storage (G). These models found there way into a fantastic array of cases and styles. Notably the Devil Diver 666 variants and various astronaut models.

Bulova actually ran the production and selling of both calibres side by side. In 1977 Bulova stopped the sales of tuning fork movements – after 17 years these models had sold over 5 millions units. It was always noted that the consumer much preferred the 214 movement and the lack of a spaceview 218 was always an odd move. If you wanted to continue the run of such a legendary movement surely you would offer up an improved version that started it all?

Some people call these watches hummers. Some loud movements will hum if you place them on a table or chest of draws. I have found that each Accutron I have come across has a different volume – some you can barely hear and others can be heard on your wrist in a quiet room. If you listen up close the sound is more akin to a screech. Listen to the audio clip below to hear a 218 movement up close. The regular beat noise is a recording error so please discard.

Accutron 50th Anniversary Spaceview

To commemorate the fiftieth anniversary of the release of the Accutron a completely updated 214B movement was surrounded in an ‘alpha’ case. It featured improvements to take modern batteries, new index guard and other changes to suit a new time. It released 1000 items to market in 2010 – at a retail price of £4,250. That’s horrendously expensive for a steel case watch and even now they are fetching large sums of money. A good condition 214 Spaceview will set you back about £600 but basic 218 movements can be picked up for £50.

As with all old things – condition should always be considered as old tuning forks can be temperamental. Suffering from electrical failure, reduced magnetism, coil failure and pawl problems. Be sure to get items serviced when they lose or gain more than 10 seconds a day.