Longines Ultra-Chron: The (Hi) Beat Goes On…

Parent Category: Content

By Adrian Hailwood

Tuesday, 10 July 2012 10:59

As we have said before on this blog, the late 1960s and early 1970s were a golden age in watch evolution. Creativity abounded and innovative technology became commonplace. It was as if the impending Quartz storm produced a frenzied search to find something – anything – to ward it off...

The pinnacle of simple watchmaking was the introduction of the ‘Hi-Beat’ movement. Movement speeds are measured in either Hertz (one complete cycle of the escapement back and forth per second) or VPH (the number of movements in either direction per hour). Dividing the VPH by 360 will give a figure twice that of the Hertz – an important point to remember when comparing speeds.

In the 1960s, most movements ran at 2.5 or 3 Hz; the Hi-Beat movement pushed this up to 5Hz. The greater speed meant better stability and more accuracy – most Hi-Beat watches were within chronometer standards by default.

This accuracy came at a price. The movements consumed more power meaning that power reserve was lower, mainsprings had to be stronger and more wear and stress was put on the movement. Even the oiling was a problem as the speed of rotation could throw the oil off the parts.

The first ‘Hi-Beat’ watch was produced by Girard-Perregaux in 1965 but the power reserve was too low to be practical and so the Longines Ultra-Chron was the first successful movement of this type. They solved the oiling issue by using a dry coating of molybdenum bi-sulphide to lubricate the escapement.

At the time, Longines marketed the Ultra-Chron as the ‘most accurate watch in the world’ guaranteeing a precision within 2 seconds per day.

Sadly this milestone of 5Hz paled beside the quartz watch frequency of 32,768Hz and so another technical achievement was discarded – but not for ever. The resurgence of mechanical watchmaking has renewed interest in the ‘Hi-Beat’ movement. Seiko kept the flame alive with their 5Hz ‘Grand Seiko’ models. In 2010 Breguet used ultra-light silicon components to push the bar up to 10Hz for their production models while TAG Heuer have produced a concept watch running at a staggering 1000Hz.

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