The Most Complicated Watch Ever, the Vacheron Constantin Berkley Grand Complication with Chinese QP

Back in 2015, on the occasion of the brand’s 260^th anniversary, Vacheron Constantin unveiled the Reference 57260, a pocket watch made-to-order for a collector considered the most complicated in the world – with no fewer than 57 complications, including Gregorian, Judaic, and lunar calendars. On the occasion of Watches & Wonders 2024, the Geneva-based manufacture goes even further with another commissioned piece (by the same collector), the Vacheron Constantin Berkley Grand Complication. Uniting no fewer than 63 complications, including the first Chinese Perpetual Calendar, it becomes the most complicated watch ever created. Again!

Before delving into the details and intricacies of this utterly complex creation, a few words about its story. It took a dedicated team of three watchmakers an impressive 11 years to craft this exclusive bespoke timepiece, with one entire year devoted solely to the assembly process! Such a journey exemplifies a remarkable human endeavour and adventure. Witnessing individuals – be it the patron, the brand, or the skilled watchmakers – undertake such an ambitious project is truly fascinating.

The Berkley Grand Complication is a commission from the same collector, Mr. Berkley (whose name had not been disclosed until today), who also commissioned the already mind-blowing Reference 57260. It is a creation of Vacheron Constantin’s Les Cabinotiers department, which specializes in crafting bespoke timepieces. Its name, “the Berkley”, will inevitably bring to mind those of Henry Graves and James Ward Packard, who commissioned and gave their names to famous Patek Philippe and Vacheron Constantin grandes complications about a century ago… 

The Vacheron Constantin Berkley Grand Complication is an evolution of the 57260, which is why it shares the same look and the same proportions with an imposing 98mm x 50.55mm case in 18k white gold. However, it brings the total number of complications from 57 to now 63. Notably, if the 57260 featured a Hebraic perpetual calendar, the Berkley is the first mechanical watch to feature a Chinese perpetual calendar (set until 2200). This was one of the main technical challenges of this new timepiece.

What makes the reproduction of the Chinese calendar particularly difficult is its irregularities, which require algorithms to transcribe them into a mechanism. According to Vacheron Constantin, it is driven by three mechanical brains to display the date of the lunar year over a 19-year cycle – as the Chinese calendar used this “metonic” cycle, a period of 235 lunations, to insert leap months in their lunisolar calendar – combined with a sexagesimal cycle for the 10 celestial stems and 12 earthly branches.

For more information, please consult vacheron-constantin.com.

TIME MEASUREMENT

1. Regulator-type hours, minutes and seconds for mean solar time
2. Retrograde second for mean solar time 
3. Day and night indication for reference city 
4. Visible spherical armillary tourbillon regulator with spherical balance spring
5. Armillary sphere tourbillon
6. World time indication for 24 cities
7. Second time zone hours and minutes (on 12 hours display)
8. Second time zone day and night indication
9. System to display the second time zone for the Northern or Southern
   hemispheres 

GREGORIAN PERPETUAL CALENDAR

10. Gregorian perpetual calendar
11. Gregorian days of the week
12. Gregorian months
13. Gregorian retrograde date 
14. Leap-year indication and four-year cycle 
15. Number of the day of the week (ISO 8601 calendar)
16. Indication for the number of the week within the year (ISO 8601 calendar)

CHINESE PERPETUAL CALENDAR

17. Chinese perpetual calendar
18. Chinese number of the day
19. Chinese name of the month
20. Chinese date indication
21. Chinese zodiac signs
22. 5 elements and 10 celestial stems
23. 6 energies and 12 earthly branches
24. Chinese year state (common or embolismic)
25. Month state (small or large)
26. Indication for the Golden number within the 19-year Metonic cycle
27. Indication for the date of the Chinese New Year in the Gregorian calendar

CHINESE AGRICULTURAL CALENDAR

28. Chinese agricultural perpetual calendar
29. Indications of seasons, equinoxes and solstices with solar hand

ASTRONOMICAL INDICATIONS

30. Sky chart (calibrated for Shanghai)
31. Sidereal hours 
32. Sidereal minutes
33. Sunrise time (calibrated for Shanghai)
34. Sunset time (calibrated for Shanghai)
35. Equation of time
36. Length of the day (calibrated for Shanghai)
37. Length of the night (calibrated for Shanghai)
38. Phases and age of the moon, one correction every 1027 years

SPLIT SECONDS CHRONOGRAPH

39. Fifths of a second chronograph (1 column wheel)
40. Fifths of a second split-second chronograph (1 column wheel)
41. 12-hour counter (1 column wheel)
42. 60-minute counter

ALARM

43. Progressive alarm with single gong and hammer striking
44. Alarm strike / silence indicator
45. Choice of normal alarm or carillon striking alarm indicator
46. Alarm mechanism coupled to the carillon striking mechanism
47. Alarm striking with choice of grande or petite sonnerie
48. Alarm power-reserve indication
49. System to disengage the alarm barrel when fully wound

WESTMINSTER CARILLON

50. Carillon Westminster chiming with 5 gongs and 5 hammers
51. Grande sonnerie passing strike
52. Petite sonnerie passing strike
53. Minute repeating
54. Night silence feature (between 22.00 and 08.00 hours – hours chosen by the owner)
55. System to disengage the striking barrel when fully wound
56. Indication for grande or petite sonnerie modes
57. Indication for silence / striking / night modes

ADDITIONAL FEATURES

58. Power-reserve indication for the going train
59. Power-reserve indication for the striking train
60. Winding crown position indicator
61. Winding system for the double barrels
62. Hand-setting system with two positions and two directions 
63. Concealed flush-fit winding crown for the alarm mechanism