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Golay SA / Longines L400 – Hybrid – P1, Experimental Prototype, 1966
Prototype category: experimental proof of concept
Description: plated brass cased (chronometer competition configuration) experimental electromechanical – quartz – hybrid movement. Lid attached to the case by 4 screws. Eccentrically located aperture for the dial, covered with a flat acrylic crystal. Movement number (= cal. L400 prototype serial number) engraved in one corner of the lid. Case with 4 holes to accept screwed lid and two holes for mounting the movement. Recess for the crown and aperture for the stem with adjacent contact plug. Construction of the movement on two, opaque green, superposed circuit board wafers (not containing integrated circuits) attached to each other with two screws. Two levels of individual transistors.
Lower level accepting two 1.35V batteries, a glass capsule containing the 12KHz quartz bar. This lower wafer is prepared to be screwed onto the plated brass case with two screws.
Upper level accepting the remaining transistors, the contacts for the positive poles of the batteries and the fragmentary cal.: L400. Latter movement fragment shows a connection with the divider chain array by means of a soldered electrical cable to the stepping motor assembly. The fragmentary L400 movement is fixed with two miniature screws to an incomplete copper ring, itself soldered to metal pins integrated into the upper wafer. The bridge holding the hand setting mechanism and the wheel work for the hands is partially cut off, it shows fragmentary engraved info ‘L400 Longines Swiss, 13 Jewels (when complete), 11.882.932’. The white coloured, brass dial is fixed to the movement with one screw at ‘minute 26’. Dial signed ‘Longines’ at ’12’. black printed minute track, remnants of ‘chronometer competition detection sticker’ at ‘6’. Plated brass hands, the tip of the second hand hand coloured in black. Anonymous brass crown.
Movement: Longines cal.: L400 electromechanical – quartz hybrid, #11.882.932 (electromechanical part made 1961 – 1963, modified and combined with quartz circuitry in early 1966)
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Golay SA / Longines L400 – Hybrid – P4, Experimental Prototype, 1966
Prototype category: experimental proof of concept
Description: Uncased experimental electromechanical – quartz – hybrid movement. Construction of the movement on two, opaque brown, superposed circuit board wafers attached to each other with two screws. Two levels of individual transistors (some smaller, less in number and in slightly different configuration as compared to P1).
Lower level accepting two 1.35V batteries, a custom made brass tube containing the 12KHz quartz bar. This lower wafer is prepared to be screwed onto a plated brass case with two screws.
Upper level accepting the remaining transistors (slightly less and in different configuration as compared to P1), a black, square, primitive integrated circuit replacing some transistors, the contacts for the positive poles of the batteries and the fragmentary cal.: L400. Latter movement fragment shows a connection with the divider chain array by means of a soldered electrical cable to the stepping motor assembly. The fragmentary L400 movement is fixed with two miniature screws to an incomplete copper ring, itself soldered to metal pins integrated into the upper wafer. The bridge holding the hand setting mechanism and the wheel work for the hands is partially cut off, it shows fragmentary engraved info ‘L400 Longines Swiss, 13 Jewels (when complete), 11.882.950’. The white coloured, brass dial is fixed to the movement with one screw at ‘minute 26’. Dial unsigned. Black printed 5 minute track and minute dots, intact ‘chronometer competition detection sticker’ at ‘6’. Plated brass hands, the tip of the second hand hand coloured in black. Anonymous brass crown.
Dimensions: movement overall: 44 x 44 x 12.3mm
Movement: Longines cal.: L400 electromechanical – quartz hybrid, #11.882.950 (electromechanical part made 1961 – 1963, modified and combined with quartz circuitry in early 1966)
Additional Info: Following the explanations above and in the parent section, these pieces are the base for the development of Longines’ ‘Ultra-Quartz’ model finally launched in 1971 and pertinent ‘partial’ prototypes for the Rolex ‘Oysterquartz’ models of 1977.
Albeit some pieces are clearly marked with the ‘Longines’ name and the winner of the chronometer competition in the category of electronic pocket sized watches in 1966 (P2: #11.882.946) being clearly and repeatedly marked as such for the press photos, all four pieces were exclusively made at the Golay facilities and remained in possession of B. Golay SA until bankruptcy in 1974, except for #11.882.946 which was transferred to Longines and is now displayed in the Longines Museum in St. Imier (3).
The tips of the second hands are hand coloured in black to enable the detection of their passage in front of the chronometer detection sticker at ‘6’. As the second hand passes by, the narrow, white line on the sticker is covered by the second hand and a photo-sensitive detector registers its passage, repeatedly measures the time until the next ‘covering of the white line on the sticker’ and compares it with the reference clock at the observatory to determine the precision of the movement (3).
One astounding fact concerning the development of the Swiss wrist watch sized quartz movement is, that the procedure of miniaturisation was successfully advancing simultaneously in collaborating institutions (CEH) and singular manufacturers independent of each other: In early 1966 B. Golay SA was on the verge of getting the quartz system almost small enough for the wrist, whereas during the same period Dr. A. Frei, senior engineer at the CEH, managed to develop an electronically controlled quartz module of only 27mm in size setting the first mark for the following wrist sized quartz revolution.
The custom made brass cylinder for housing the quartz bar of #11.882.950 might be the earliest known successful Swiss attempt of custom adaptation and miniaturisation of the quartz element. As the quartz bar would need to be placed inside a ‘vacuum chamber’, to avoid energy loss due to friction with air, the technical defeat was enormous. Not only the container was required to be air tight, but the means to remove the air from the container and seal it afterwards needed to be developed (3). This experimental piece has been submitted to the observatory chronometer competition of 1966 along with #11.882.946 bearing the number ‘P 97’, but its performance was not good enough to be ranked.
Please refer to the parent section for further historical info and the context during which these experimental prototypes were created.
Ref.:
- Goldor.
- 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
- 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).
- Journal Longines, March 1965, courtesy of Longines’ Heritage Service
Electric Watch Prototypes 