Golay SA – Longines – Ultra-Quartz Prototype

Golay SA – Longines, Ultra-Quartz Prototype, ‘late’ Version, 1970

Category: functional prototype

Description: Symmetric, tonneau-shaped, stainless steel cased prototype. Case back with ingenious and unique fixing system consisting of two articulated brass bars press fitting the case back to the case front. Back showing company info and future reference number ‘8482-1′ on the inside and ’34’ as well as the material declaration on the outside. Battery cover stamped with company info. Recess and aperture for the crown. Light cream coloured, brass dial with black printed ‘Longines’ at ’12’ and black printed hour and minutes marks, ‘T-Swiss Made-T’ printed in black below ‘6’. Trapezoid aperture for the date at ‘4:30’. Brass hands. Acrylic crystal, ribbed, stainless steel crown on the back of the case.

Dimensions: 38mm, lug – lug: 40mm, lug width: 22mm

Movement: L6512 Prototype, unnumbered

Additional info: This prototype predates the industrially produced models by about one year. Despite an almost identical case, it shows several differences as compared to the marketed version starting with the dial, which resembles versions used for chronometer testing. However, during the development of these updated, ‘late’ ‘Ultra-Quartz’ prototypes after March 1970, there was no precision testing at the Observatory. These simple and neutral dials were used to hide the electronic nature of the movement during functional testing on the wrist, by the engineers at B. Golay SA.

The dial has no applied logos or indexes, it’s just printed black on light cream. The articulated bars for fixing the case back are made of brass, in the definitive version they will be chrome plated or manufactured in stainless steel.

The hands are crude brass and not coated, the crown does not correspond to the marketed version, which will resemble to the stirrup shaped ‘crown’ of the Accutron. The script on the battery cover is slightly different.

As explained in the parent section, the first, ‘early’ prototype version of this caliber had to be massively redesigned during technology transfer, as the ‘earlier’ prototypes were not suited for industrial production. With the bankruptcy of Golay SA in 1975, all prior prototypes have allegedly been destroyed, together with all internal documentation. Therefore, this prototype, despite being of the ‘later’ type, represents the earliest surviving ‘Ultra-Quartz’ version known, as well as being the earliest representative of the redesigned version (1, 2).

Thus, this prototype was made between March 1970 and February 1971. Next to the regulation and testing of the electronic module prior to assembly and after assembly of the movement, functional testing on the wrist remained the only test phase of the new caliber concept, resulting the flaws of the quartz suspension to be overseen. Therefore, many of the about 2000 produced ‘Ultra-Quartz’ models stopped to work (1, 2).

Provenance: This prototype originates directly from an engineer having worked for B. Golay SA from 1965 to 1975. He has participated to the development of the discreet circuitry for the L-400 hybrid prototypes, the circuitry for the L6512 caliber and its successor. He wore this prototype for functional testing.

Ref.:

  1. Personal communication with a senior engineer directly involved in the prototype and watch developments and construction at B. Golay SA from 1965 to 1975.
  2. Donzé P.Y., Dynamics of Innovation in the Electronic Watch Industry: A Comparative Business History of Longines (Switzerland) and Seiko (Japan), 1960-1980, The Journal of the Economic & Business History Society , © 2019, The Economic and Business History Society.