To be a recipient of one of the 19 annual Grand Prix d’Horlogerie de Genève (GPHG) awards is the most prestigious recognition of excellence in the world of watches. Among this year’s winners, announced at a ceremony in Geneva in November, is the Vacheron Constantin Traditionnelle Twin Beat Perpetual Calendar, which took home the “Innovation Prize” for “the best watch that offers an innovative vision of time measurement and opens up new development pathways for the art of watchmaking”. This prize is discretionary so the qualifying piece has to be an exceptional example.
As the world’s first timepiece with two balances, the Traditionnelle Twin Beat Perpetual Calendar is certainly exceptional, allowing its owner to switch between high-frequency Active mode and low-frequency Standby mode to extend the power reserve up to 65 days. Inside its 42mm platinum case is the remarkable manual-winding calibre 3610 QP which, despite its 480 components, is only 6mm high and 32mm in diameter. The mainspring is transformed into a source of variable energy levels through a pusher at 8 o’clock, which facilitates the switch from one frequency to another, depending on the activity level of the wearer. On the wrist, the wearer gets the most out of the watch by keeping it in Active mode, which features a 5Hz (36 000 vibrations per hour) balance and four-day power reserve. If unworn for some time, the watch can be switched to Standby mode, which runs on a second balance with a drastically reduced frequency of 1.2Hz (8 640 vibrations per hour).
Ensuring this smooth operation is the mode selector, which allows only one balance wheel to oscillate at a time. The switch is designed to be instantaneous and avoid any lag when shifting between modes. This guarantees that the timekeeping operations of the movement are never interrupted. Both the Active and Standby balances are driven by the same mainspring barrel. A new hairspring, comparable to the finest human hair, was created for the highly-sensitive Standby balance. This hairspring is almost four times smaller in cross section than that of the Active balance. Because time display was also a challenge, with the hour and minute hands having to draw variable information from two gear trains, a gear differential was employed to read more than one input source of timekeeping data. The instantaneous jumping indications for the date, month, and leap year of the perpetual calendar mechanism have also been redesigned to consume as little energy as possible.
Priced at approximately R4.3-million, the Traditionnelle Twin Beat Perpetual Calendar features contemporary dial design and movement aesthetics, successfully combined in a more classic platinum case with a hand-stitched grey American-alligator leather strap. The slate-coloured dial features radial hand engraving, and white-gold hour indexes are set into a sapphire-crystal dial plate, with frosted sub-dials laser engraved and ink filled for a seamless appearance.
• Local enquiries through RLG Africa 011-317-2600
• From the December edition of Wanted 2019.