Vacheron Constantin broke the record for most complicated watches with the Ref. 57260 in 2015. However, the company has now surpassed that record with its new "Les Cabinotiers The Berkeley Grand Complication." Ordered by the same owner as the Ref. 57260, this masterpiece boasts 63 complex functions, including an extremely intricate Chinese calendar perpetual calendar.
Vacheron Constantin has completed the Cal. 3752, an unprecedentedly complex movement. It features 63 functions, including the world's first perpetual calendar using the Chinese calendar, as well as a sonnerie and an armillary tourbillon. The development period spanned 11 years. The left image shows the dial side of the movement, and the right image shows the case back side. It is a hand-wound movement (72mm diameter, 36mm thickness). It has 245 jewels, 18,000 vibrations per hour, and a power reserve of approximately 60 hours. It consists of 2877 parts.
Text by Masayuki Hirota (Chronos-Japan)
Text & Edited by Yukiya Suzuki (Chronos-Japan)
Edited by Yuto Hosoda (Chronos-Japan)
[Article published in the July 2025 issue of Kronos Japan]
Vacheron Constantin's expertise that broke world records
The 2015 "Reference 57260" and the 2024 "Les Cabinotiers The Berkeley Grand Complication" are, in a sense, twin watches. The order to create the most complex watch possible, equipped with a Jewish perpetual calendar, took eight years to realize the 57260. During that process, the same client began to wonder if it would be possible to create an even more complex watch incorporating a Chinese perpetual calendar. This led to the creation of "The Berkeley," which took 11 years to complete. With 877 parts, 245 rubies, and 9 discs, its movement not only boasts an astonishing 63 functions but also features a Chinese perpetual calendar.
The Chinese calendar is a lunisolar calendar (old calendar) that combines the lunar calendar, based on the cycle of the moon's phases, with the solar calendar, based on the Earth's orbit around the sun. While several manufacturers have used this Chinese calendar in their calendar watches, it has been considered impossible to create a perpetual calendar based on the extremely irregular Chinese calendar. The biggest problem is the leap month inserted every two to three years, which occurs seven times in a 19-year cycle. Vacheron Constantin's engineers not only programmed this irregular calendar but also made it possible to display the Spring Festival, which constantly changes between January 21st and February 21st. It could be said that this was only possible because of the large size of the pocket watch, but it is a fact that a perpetual calendar based on the Chinese calendar has not existed until now.
Beyond these features, The Berkeley is truly exceptional. It boasts a 24-city world time display, a second time zone display with day/night indicator, a sonnerie with five hammers and gongs, a three-axis tourbillon, a Gregorian calendar perpetual calendar, an equation of time display, a sky chart, a split-seconds chronograph, and an alarm. And importantly, this watch actually works.
The reason Vacheron Constantin was able to create the 57260 and the more complex The Berkeley lies in the know-how cultivated by Les Cabinotiers. To increase functionality, one can divide the movement into multiple layers and assign a function to each layer. This is why Dubois-Depraz was able to create modular chronographs and IWC was able to create perpetual calendars. However, when it comes to ultra-complicated watches with a large number of parts, the problem is not so simple. This is because the more layers there are, the more prone to malfunctions there are. In contrast, Les Cabinotiers has accumulated know-how in designing and operating these layers. The culmination of this can be said to be The Berkeley in 2024.
However, that know-how cannot be acquired overnight. To give an example of a typical complex mechanism, the play in a single part is about 2/100ths of a millimeter. However, when these are added up, the overall play expands to 20/100ths of a millimeter, and the watch stops working. In contrast, with Les Cabinotiers, the goal was not to reduce the play in a single part, but to reduce the overall play to less than 2/100ths of a millimeter. What is needed is excellent design, precise parts, and, more importantly, watchmakers capable of assembly down to the micron level. This is why it took a year just to assemble The Berkeley.
This ultra-complicated timepiece was created at the request of William R. Barclay, a world-renowned watch collector. He also commissioned the Ref. 57260, and desired the world's first perpetual calendar using the Chinese calendar, which has now been realized in this piece. After 11 years of development, this watch boasts 63 functions—six more than the Ref. 57260. Ref. 9901C/000G-B472. Manual winding (Cal. 3752). 18K white gold case (98mm diameter, 50mm thickness). Weight 980g. Not water resistant. A unique piece.
The Berkeley has once again surpassed the complexity achieved with the 57260. It's likely that no more complicated timepieces will ever be made. However, if there is any manufacturer that could surpass this level of complexity, it would undoubtedly be Vacheron Constantin.
