Vacheron Constantin: The Twin Beating Cross

by Dr Kenny Pang

Vacheron Constantin marks another remarkable feat in its 264 years of fine watchmaking at SIHH 2019 with its Traditionnelle Twin Beat Perpetual Calendar.

This user controlled dual-frequency timepiece is analogous to the beating heart (where it gets its name). Displaying the hours, minutes, date, month, leap year cycle and power reserve on its dial, it can, in Active mode beat at a high frequency required for a modern active lifestyle when worn; and can be switched to Standby mode to slow down its beat to achieve an extended power reserve of at least 65 days.

The in-house developed calibre 3610 QP powering the Twin Beat is a masterpiece in its own right. It is inspired by the seasonal system from the Japanese Edo Period (1603 – 1868), which divided the day and night into six segments during which the length of daylight varied from one season to another. Clocks from this period were equipped with a single or double foliot balance allowing automatic changes in the timepiece operating speed.

This Twin Beat® system works on an all-or-nothing principle (with a mode selector), allowing only one balance to oscillate at a time.

The Active (5Hz) and Standby (1.2Hz) balances are driven by the one same mainspring barrel, which is the most efficient way of distributing energy and the only way to have a single power-reserve indication. The switch from Active mode to Standby mode (and vice-versa) has to be from one’s own volition, unlike the human heart that would beat slower (by about 20% slower) at night involuntarily during one’s sleep (at rest).

At an exclusive interview with the Maison’s Chief Marketing Officer Laurent Perves, we asked “why not allow this intelligent perpetual calendar timepiece automatically switch itself to the standby mode, like the human heart at night during sleep?”. Perves shared that the Maison has considered that “not every individual sleeps at the same time every day, and that Vacheron Constantin did not want to seem to “dictate” that the watch owner had to be in bed by midnight.” (A good point thoughtfully addressed).

A few challenges faced this complex, innovative and unique timepiece:

  1. The energy needed to maintain the perpetual calendar mechanism and the jumping indicators require a lot of energy. Vacheron Constantin’s new in-house (patent pending) redesigned jumping mechanism using a sprung dual gear compound system requires four times less torque than the conventional jumping mechanism.
  2. Due to the highly sensitive Standby balance, similar to the finest human hair, the cross sectional area (0.0774mm by 0.0159mm) is four times smaller than the hair spring of the Active balance.
  3. As there are two balance wheels and power source, the reading of time would require that both gears are able to transmit the power to the hours and minutes hands (using two differential gears).

Through technological micro-engineering feats, the calibre is only kept to 6mm thick and 32mm in diameter.

Just as the internal heart beats viscerally for every living organism, regardless of shape, size, form or morphology, this Twin Beat® innovation beats for a lovely and beautifully orchestrated dial. The upper half is hand guilloche slate coloured dial, while the lower half of this masterpiece reveals the fully exposed date and month dials, and with the leap year counter in the lower middle. The black oxidised gold frequency mode indicator (5Hz and 1.2Hz, colour coded with the complimentary power reserve indicator) located at the 9 and 10 o’clock position; the power reserve indicator sits triumphantly at the 12 o’clock position indicating the mammoth feat of 65 days power reserve. White gold applied hour markers, with white gold minute and hour hands are distinct.

This Traditionnelle Twin Beat Perpetual Calendar is by far the most innovative introduction in the entire plethora of beautiful watches this SIHH 2019. A pertinent point about this timepiece, it is beyond ‘concept’ and is commercially available for purchase by the strong-hearted. Your heart might just skip a beat on sight of this masterpiece.


Images courtesy of Vacheron Constantin, artwork by Curatedition.


Related link:

Salon de la International Haute Horlogerie 2019



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