Before the completion of Les Cabinotiers Reference 57260 featuring a Hebraic perpetual calendar, Vacheron Constantin had already embarked on another record-breaking project.
The same commissioner and watchmaking trio set out to make the world's most complicated timepiece and the world's first Chinese perpetual calendar programmed until 2200.
The 11 years of research and development culminated in 2024 with the unveiling of Les Cabinotiers – The Berkley Grand Complication and its double-sided Calibre 3752.
Vacheron Constantin pushed its own limits by integrating 63 complications into this mechanical masterpiece, which surpasses the 57 for the Reference 57260 from 2015.
The challenge was to translate the complexity and irregularity of the Chinese lunisolar calendar into cams and gears forming a perpetual horological configuration.
Based on the lunation, a month lasts 29 or 30 days. As 12 lunar months are 11 days shorter than a solar year, a 13th intercalary or embolismic month is incorporated into the Chinese calendar every two to three years, totalling seven times over the Metonic cycle of 19 years, by which the lunar and solar systems become synchronised.
Displays on the back side include indications of the Chinese agricultural perpetual calendar. photo:
This results in the varying number of days in common and embolismic years as well as the fluctuation of the start of the Chinese New Year between Jan 21 and Feb 21.
Other principles include the numbered units of time, based on the association of 10 celestial stems and 12 earthly branches -- yielding a possible total of 60 different combinations.
This so-called sexagesimal cycle is most often used to mark the passing of years, but can also be applied to months, days or hours. The stems associate with five elements and a yin-yang polarity while the branches are represented by 12 signs of the Chinese zodiac.
Thanks to 11 out of the 63 complications, elements of the Chinese calendar are indicated in apertures and counters on the front of Les Cabinotiers – The Berkley Grand Complication.
The watchmakers went so far as to offer a disc-type display of the exact date of the Chinese New Year at 6 o'clock while a silhouette of the zodiac animal appears in a window positioned below the moon phases at 12 o'clock.
Calibre 3752 with 2,877 components. photo:
Two other complications drive the Chinese agricultural perpetual calendar and indications of seasons, the equinoxes and the solstices with a solar hand on the back of the sophisticated timepiece in a white gold case.
Moreover, the technical feat involves 44 complications for time measurement and regulation, the Gregorian perpetual calendar, astronomical indications, split-seconds chronograph, alarm functions and Grande Sonnerie.
Six other complications operate additional features such as the power reserve indications and winding system for double barrels.
The construction of Calibre 3752, comprising nine discs, 31 hands and 2,877 components, is complemented by meticulous decoration and finishing, expressing Vacheron Constantin's art of watchmaking.
