A Zenith chronometer calibre brought to light

A monumental collaboration in watchmaking is born. Zenith makes its most awarded movement from the golden age of chronometry competitions available to acquire for the first time ever.

Based on an idea initiated by Phillips’ Aurel Bacs and Alexandre Ghotbi, Phillips in Association with Bacs & Russo invited renowned independent watchmaker Kari Voutilainen to restore and hand-decorate a batch of Zenith Calibre 135-O movements, all of which took part and won in observatory chronometer competitions. The result is a contemporary chronometer produced in a series of 10 pieces and sold exclusively by Phillips in association with Bacs & Russo.

In a privatised cinema in Geneva, guests were invited to journey back in time to the 1950s with the premiere of a short film that recounts the tale of this extraordinary collaboration. The story begins during the last great decade of observatory chronometer competitions, an era of watchmaking that is brimming with creativity and the pursuit of chronometric perfection. It is during this decade that Zenith solidified its reputation as a preeminent maker of precision chronometers with the Calibre 135-O, the most highly awarded observatory chronometer ever made. Seven decades later, Phillips auction house proposed a new kind of challenge for Zenith: to work with one of the most highly esteemed living independent watchmakers in order to restore and decorate a handful of Calibre 135-O movements that actually took part in and won observatory chronometer competitions, and to house them in a totally new watch that is at once historically inspired and contemporarily singular.

Developed from 1945 onwards by Ephrem Jobin, Calibre 135 was produced from 1949 until 1962 in two distinct versions: a commercial variant, and a second iteration made solely for taking part in chronometry competitions at the Observatories of Neuchâtel, Geneva, Kew Teddington, and Besançon. These “O” movements, which were never commercialised nor cased in wrist or pocket watches, underwent exhaustive testing through drastically different temperatures, shocks and running in 6 different positions, consistently delivering optimal chronometric performance with minimal variations in rate. With over 230 chronometry prizes, the Calibre 135-O holds the most awards of any observatory chronometer calibre in the history of watchmaking.

The 10 movements chosen for this very limited edition belong to the “serial winning” years from 1950-1954, when the 135-O won the competition 5 years in a row – an unheard of and unmatched feat. They were prepared for the competitions and fine-tuned yearlong by the Zenith Laboratoire de Chronométrie. All 10 movements were awarded prizes within the 1st category range and had all been regulated by celebrated chronométriers Charles Fleck & René Gygax, who worked on the prize-winning movements five years in a row and bolstered Zenith’s reputation as an undisputed leader in precision chronometry.

Tasking Kari Voutilainen with the restoration and finishing of these historical movements elevated them from raw competition pieces to haute horlogerie creations of the highest order.

True to its original era, the Calibre 135 Observatoire is inspired by past commercial wristwatch versions of the Calibre 135, yet unlike anything ever made in the past, the Observatoire Limited Edition draws inspiration from several 1950s references by combining the most emblematic details with contemporary accents. The 38mm platinum round case features tapered lugs that seamlessly fit under the bezel, as well as an oversized notched crown emblazoned with the modern Zenith star logo.

Beneath the sapphire glass box, the slightly domed black dial in sterling silver by Kari Voutilainen’s Comblémine atelier features guilloché engraving in a fish-scale motif. Triangular hour markers and applied polished dot markers in rhodium-plated German silver and solid gold hands are juxtaposed in a blend of vintage elegance and contemporary opulence. The oversized second counter at 6 o’clock is inscribed with the movement’s serial number, denoting the unique nature of each of these watches and how each was thoroughly regulated by revered chronométriers Charles Fleck or René Gygax, then passed on the supremely skilled hands of Kari Voutilainen and his dedicated team of artisan watchmakers. The dial is signed “Neuchâtel” at the bottom, as Zenith, Kari Voutilainen and the historical Observatory where the Calibre 135-O competed and won during the golden years of chronometry competitions are all based in the Canton of Neuchâtel.

For the first time in the history of the Calibre 135 and certainly for the “O” variant, the observatory chronometer movement that has been impeccably decorated and finished by Kari Voutilainen is visible through a sapphire display back. Cleaned and finished by the master restoration watchmaker, the aesthetic of the historical movement has been refined with hand chamfered and polished edges on the gold-coloured bridges, bevelled and polished screw-heads, circular graining on the main plate, snailed brushing on the ratchet and crown wheels and much more.

Perfectly fitting the historical context of this exceptional series, the Calibre 135 Observatoire is delivered in a wooden box crafted from walnut wood with brass fasteners, inspired by the containers in which the chronometry competition calibres were transported from the Zenith Manufacture to the Neuchâtel Observatory.

June 23, 2022