SimplyAbuDhabi XXXIII

1 1 3 S I M P LY A B U DH A B I P erpetual calendars are one of the most challenging high complications in haute horlogerie, and they featured prominently at SIHH 2019. The Traditionnelle Twin Beat Perpetual Calendar by Vacheron Constantin delivered unprecedented accomplishment allied with true innovation. This visually arresting watch has been designed so the wearer can choose between dual frequencies. The brand’s new patent-pending system permits timekeeping transition between high-frequency Active mode (5Hz) and low-frequency Standby mode (1.2Hz) without any recorded losses. When worn the watch displays the hours, minutes, date, month, leap year cycle and power reserve on its dial, and when taken off, the in-house developed calibre 3610 QP can be set to standby mode, which slows the mechanics down to guarantee an extended power reserve of at least 65 days. Vacheron Constantin state that, “One of the most basic assumptions of mechanical watchmaking used to be that the energy output of the mainspring barrel had a fixed timespan, with very little deviation from the stated power reserve. The Traditionnelle Twin Beat Perpetual Calendar transforms the mainspring into a source of variable energy levels, giving fine mechanical watchmaking a completely new degree of versatility.” This unprecedented technical feat is operated by a pusher at 8 o’clock. In Active mode, the wearer has 4 days of power reserve, and when off the wrist and switched to Standby mode, the maximum power reserve is extended to at least 65 days. At any point during the Standby mode running time, the Traditionnelle Twin Beat Perpetual Calendar can be switched back to Active mode and re-worn, with all its calendar indications perfectly up to date. Normally, a perpetual calendar watch has to be set before being worn, but with this striking development, which makes a classic complication more viable in the modern age where convenience is king, a hand-wound perpetual calendar can now be left unworn for over two months, and picked up and immediately won again, still displaying the correct date and month. The designer geniuses at Vacheron Constantin took inspiration for this timepiece from by the seasonal system of the Japanese Edo Period (1603 – 1868), which divided day and night into six segments, of which the length varied from day to night and from one season to another. Clocks from this period were equipped with a single or double foliot balance enabling automatic changes in their operating speed. Guests at SIHH 2019 could see a similar Japanese lantern clock from the very beginning of 18th century, exhibited on Vacheron Constantin’s booth. The display of hours and minutes might seem straightforward in comparison to this remarkable new feature, but they were also challenging. Because the calibre 3610 QP has two balance wheels, only one of which is allowed to oscillate at one time, the hour and minute hands have to draw variable information from two gear trains for one reading of the time. This is accomplished by a gear differential that allows the hands to read more than one input source of timekeeping data. A second differential is mounted on the barrel for the dual purpose of winding the mainspring and also reducing the mainspring torque as it is directed towards the Standby mode balance (armed with a delicate hairspring created especially for the slow-beat balance). Two final differentials translate the power reserve into the sub-dial that indicates remaining mainspring wind. Impressive stuff. The Traditionnelle Twin Beat Perpetual Calendar is also surprisingly compact considering there are 480 components in the calibre 3610 QP. The movement measures just 6mm in height and 32mm in diameter— outstanding micro-engineering. The aesthetics of the watch reveal a masterful alliance of tradition and modernity. The dial shows the distinctly 18th century art of engine turning and frosted finishing, transmuted into clean radial guillochage and sand-blasted surfaces. The dial is split into two main segments, with the gold dial segment decorated with hand-guillochage and then fitted within an outer segment of sapphire crystal. The gold hour indexes are subsequently set into the sapphire-crystal dial segment, which is then laser-engraved and ink- filled for a contemporary sleek and crisp legibility. Vacheron Constantin has been achieving horological excellence for 264 years, and this highlight of SIHH makes a momentous addition to the brand’s rich heritage and global reputation for creating the world’s finest timepieces. VACHERON CONSTANTIN TRADITIONNELLE TWIN BEAT PERPETUAL CALENDAR