Golay – Longines

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In 1955, a research unit was set up at Longines, devoted to developing electronic time pieces. This unit was not integrated into the department of mechanical production, which was responsible for the organisation of production in the brand’s workshops. The unit became even more autonomous in 1964 when the R&D department was separated from technical management and was directly moved under the control of general management (7). In August 1964, Longines approached Bernard Golay and Jean – Claude Berney of the company B. Golay SA in Lausanne, to discuss the possibility of developing a quartz controlled, small sized clock to submit to the Neuchâtel Observatory chronometer competition of the same year. To be validated, an entry for this competition would need to be submitted until 26.10.1964 the latest (4).

The Foreplay: Calibre L800

In only 2.5 months B. Golay SA, already specialised in microelectronics, together with Longines would present a small sized ‘pendulette’ (movement size: 48 x 64 x 56mm) to the Neuchâtel Observatory chronometer competition of 1964. In this piece, Longines’ experimental electro – mechanical movement L400 (see below) would be connected to a quartz (12KHz) controlled electronic system containing 25 miniaturised transistors, resistances and capacitors placed on two levels of electronic wafers giving birth to calibre L800 (4). This experimental prototype would then set a precision record in the category of ‘isolated pieces’ with an N-score of 0.15 (0 meaning absolute precision) and be admitted in a modified form to the Observatory competition of 1965 in the category of ‘electronic marine chronometers’ where it will win in its category with an N-score of 0.05 (4). The initial L800 movement was later used for the commercialisation of a very small series of brass cased ‘pendulettes’.

After the successful demonstration of their cal.: L800 at the chronometer competitions of the Neuchâtel Observatory in 1964 (category of isolated pieces) and 1965 (category of electronic marine chronometers), Longines prolonged the collaboration with engineer Jean – Claude Berney and his team of specialists. The next step would be to miniaturise the movement and thus getting it within reach for being pocket watch sized and ultimately for being worn at the wrist.

The Missing Link

To achieve this goal Jean – Claude Berney referred again to Longines’ experimental, electromechanical calibre L400, developed from 1961 to 1963, containing an unique stepping motor, and use it as a base also for the next smaller experimental prototype series.

The team around Jean – Claude Berney would take a commercially available, glass incapsulated quartz, vibrating at 12KHz, re-think the system of calibre L800 and develop a miniaturised circuitry to break the frequency down to 2Hz in order to properly activate the stepping motor of cal.: L400. As for the construction of cal.: L800, the L400 movement itself was stripped of its battery hatch, the date mechanism and the balance wheel bridge including the balance wheel. The remaining calibre consists of the stepping motor assembly and the wheel work to move and set the hands. Latter partial movement would then be combined to the aforementioned, miniaturised, hand-soldered circuit of individual transistors (at the beginning without the use of an integrated circuit) to divide the quartz frequency from 12 KHz down to 2 Hz. To the contrary of Battelle in Geneva and the CEH in Neuchâtel, Golay did not have the possibility to get a governmental clearance from the USA to use the their emerging, advanced microelectronics technology, so they were forced to used discret elements up to the development of the wrist watch sized ‘Ultra-Quartz’ model in 1969 (1, 5).

The stepping motor of cal.: L400 is worth mentioning, as it is an unique construction consisting of a coil rotatably arranged between the poles of a permanent magnet. With each 2Hz pulse from the quartz resonator divider chain, it is tilted by about 60 degrees. A small spring attached to it advances the central gear wheel which drives the wheel work moving the hands. Moreover, the motor seems to be identical to the one used years later in Rolex’s ‘Oysterquartz’ (cals.: 5035 and 5055) launched in 1977. Rolex’s electronics laboratory at the time had been set up by the engineer René LeCoultre (1918 – 2018). It is obvious that he did not want to ‘re-invent’ the stepping motor, but rather reverted to an already proven albeit experimental design (1).

The whole system runs with two 1.35V batteries and was integrated into a plated brass chronometer competition configured case. The serial numbers of the prototypes are derived from the respective cal.: L400 movement numbers (11.882.9xx, 12.xxx.xxx) within. All known experimental cal.: L400 movements were made between 1961 and 1963.

Only 5 such hybrid, experimental prototypes were made in early 1966 (3). The earliest by numbering and development is presented in a subsection (P1: #11.882.932).

The next one would be the one which won the chronometer competition in the category of electronic pocket chronometers at the Neuchâtel Observatory in 1966 (P2: #11.882.946) which is now exhibited at the Longines musueum in St Imier (3). This electronic pocket chronometer #11.882.946 winning the observatory competition contest in its category, paved the way for the pulverisation of all previous precision records by the quartz driven, now wrist watch sized entries by the CEH in 1967. These prototypes would then go through a technology transfer and would be industrialised as Beta 21 in 1970 (see dedicated section).

A third one is in a German private collection (P3: #11.882.948) (1). The latest piece by numbering is the second version shown separately (P4: #11.882.950). A fifth piece just surfaced, but remains uncased (P5: #12.225.396)

Interestingly an evolution in miniaturisation with respective miniaturisation and reduction in number of components can be observed when comparing the details of the first (P1: #11.882.932) with the last (P4: #11.882.950) version: The number of individual transistors decreases, some transistors get smaller, a primitive (bought in) integrated circuit is added and even the encapsulation of the quartz is optimised, by abandoning the fragile glass tube and suspending the quartz bar inside a custom made brass cylinder. When comparing the dimensions, the custom made brass cylinder impresses with its smaller size as compared to the original, commercial glass housing.

These experimental prototypes represent the very last phase before the miniaturisation of major components, the development of specific, appropriate motors and batteries which later allowed for the construction of wrist watch sized quartz movements. The speed in miniaturisation of quartz controlled systems during these few years of the mid 1960s is impressive and these experimental movements certainly represent one most important missing link between experimental miniaturisation of the quartz system for industrial and professional application and applied miniaturisation for the wrist.

By observing these two prototypes (P1 vs. P4) alone, one can contemplate the aforementioned rapid, concise and targeted miniaturisation finally culminating in the development of cal.: L6512 which will emerge 3 years later as a prototype and which in 1971 will be mounted by Longines into the commercialised watch model known as ‘Ultra Quartz’.

These pendulettes, at an overall size of 50mm x 50mm x 10mm the definitive miniaturisation of the quartz movement for fitting a wrist watch was within reach. This last goal would be achieved one year later at the CEH in Neuchâtel. Indeed, in parallel to the development of their own quartz movements, Longines was also shareholder of the newly founded CEH, which managed to develop the first quartz wrist watch in 1967. Latter collaborative participation and Longines secret, unilateral projects culminating in the development of the ‘Ultra – Quartz’ watch, would prove to be a problematic conflict of interest and would ultimately lead to the resignation of the technical director of Longines, Aurèle Maire from his duties in the board of CEH (6).

Ref.:

1. Goldor.
2. Linder P.; Au Coeur d’une Vocation Industrielle: Les mouvements de montre de la maison Longines (1832-2009) Tradition, savoir-faire, innovation, Edition de Longines 2010, courtesy of Longines’ Heritage Service
3. Personal communication with a senior engineer directly involved in the prototype developments and construction at B. Golay SA from 1965 to 1974 (he constructed the circuitry himself for the 5 experimental L400 – Hybrid prototypes).
4. Journal Longines, March 1965, courtesy of Longines’ Heritage Service
5. Personal communication with a former Executive Vice-President of Ebauches SA, in charge of Research & Engineering.
6. Forrer M., LeCoultre R., Beyner A., Oguey H.; L’aventure de la montre à quartz, Centredoc, 2002
7. Watchonista