Versatile timekeeping allows switching from standby to active mode, but we're not talking about a digital smart watch.
A smarter micro-engineering feat drives the Traditionnelle Twin Beat Perpertual Calendar, a user-controlled dual-frequency mechanical watch by Vacheron Constantin.
Founded in 1755, the Swiss maison is the world's oldest watchmaker in continuous production.
Its Traditionnelle collection pays tribute to the Genevan art of watchmaking passed on from generation to generation, while boasting innovative mechanisms such as the Twin Beat.
The 3610 QP movement is actually inspired by a Japanese seasonal system from the Edo Period (1603-1868), whose clocks were equipped with a single or double foliot balance enabling automatic changes in their operating speed.
The in-house developed movement has two balances, each operating one at a time and at a different frequency. A pusher at the 8 o'clock position allows the wearer to easily switch from one frequency to another, depending on activity level.
When worn on the wrist, the watch's active mode runs on a 5Hz balance, with a four-day power reserve. When not wearing the watch and during a long period of stasis, changes to the standby mode slows down the movement, whose second balance runs with a reduced frequency of 1.2Hz while extending the power reserve to at least 65 days.
Both balances are driven by the same mainspring barrel, which is the most efficient way of distributing energy and the only way to have a single power-reserve indication.
Both the time and calendar displays are never affected when the user is not wearing the watch, which can be set flat on a table and picked up more than two months later, still displaying the correct date and month.
The model features patent-pending systems for lossless timekeeping transition between the two modes and for the perpetual calendar's instantaneous jumping indications.
The latter has been redesigned, utilising a sprung dual-gear compound system that requires four times less torque than a conventional jumping display, to indicate the date, month and leap year.
Despite the complexity, the compact movement measures only 6mm in height and 32mm in diameter while beating precisely within the high complication timepiece, presented in a 42mm platinum case.
