Lot 364

Longines

Ultra-Chron

An extremely rare, charismatic wristwatch: graduate's piece, made by a watchmaking student of the La Chaux-de-Fonds watchmaking school - CHRONOMETER - with large chronometer rating certificate, issued in La Chaux-de-Fonds on June 16, 1972

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Why is this watch at the time advertised by Longines as "The world's most accurate watch" so extremely important for the development of mechanical timekeeping?
To answer this question we must look at the situation off the Swiss horological industry at the end of the 1960s until far into the 1970s. It is time period generally known as the quartz crisis. Quartz watches were regarded as the thing of the day and at the same time mechanical watches were upgraded to a new level. the parallels to today's crisis in the automotive industry are quite obvious. How was development carried out at that time? There was a research department with electrical engineers for the quartz engineering, to be future-oriented and not fall behind the competition. At the same time however, there was also most likely in the same building a team of highly qualified designers and watchmakers dealing with mechanical developments, who had reached new heights of accuracy during their attempts to upgrade classic technology with innovative methods.
The year 1967 marked the beginning of a new era of ultra fast watch movements beating at the speed of 36000A/h (= 10A/s). Here is a simple way of demonstrating what this means: try counting to five within one second. This should be just about possible, but now try and count to 10 within one second. This is not so simple anymore but it shows you how fast the balance of a high frequency timepiece oscillates. The idea behind this development was the goal to have a watch, which was accurate even under most difficult conditions. Details in the construction had to be upgraded, i.e. wheels with 21 instead of the normal 15 teeth was required. The watch movement needed more power which meant stronger winding coils with larger barrels. The gear train was exposed to higher pressure and friction, which meant that supreme precision was imperative during production. Lubrication of the movement was also a challenge under these conditions, which was handled by using a novel dry lubricant called molybdenum disulphide. The Ultra-Chron was fitted with a number of movements with 42 hours power reserves. Among them were calibre 430 (central second), calibre 431 (central second with date), calibre 432 (hour and minutes only) and calibre 433 (date only). The date function has no fast setting functionality. The ball-bearing bimetallic rotor winds in both directions and the Glucydur balance is fitted with a KIF-Ultraflex shock protection and a flat Nivarox coil. The central second has an indirect drive. When the watch was launched at the 100-year anniversary of the company Longines in 1967 it had a deviation of +/- two seconds per day and was celebrated as the most accurate wristwatch in the world. Obtaining a chronometer certificate was not considered necessary, because the accuracy was planned to be much higher than the COSC specification.
In this our watch, which inspired this story, is the exception to the rule as it comes with a COSC certificate, issued on June 16, 1972 by the "Bureaux Suisses De Contrôle Officiel De La Marche Des Chronomètres" in La Chaux-de-Fonds. The watch was created in 1969 by Longines in 1969 as reference 7851 with calibre 431.
The real highlight of the story "Back to the future – the Longines Ultra-Chron" however, is who consigned the watch to the auction: a master-class student at the Technicum La Chaux-de-Fonds, called Yvo Simioni. He obviously attempted to improve this in its time "most accurate watch in the world" even further and achieved a mean deviation rate of 0,6 seconds and the rating "Especially good results" on the certificate. So what we have here is basically a tuned racing version of the Ultra-Chron.
The Ultra-Chron was in production over eight years and was fitted with a great variety of case forms and materials which often represent the exalted 1970s in all their glory. When taking into consideration all the efforts that went into the making of the Longines Ultra-Chron, plus the precision of the movements and the fascinating technical solutions that where devised, we have to say that today's prices on the vintage market are far under the real value of this fine timepiece. A good quality steel example can be found from 1,500 Euros up. there is no doubt that these high frequency watch movements are the peak of mechanical development of their time.
Source: ChronoHype Magazin No. 8