A year ago, Vianney Halter unveiled the Deep Space Resonance, one of the most complex and extravagant takes on the principle of resonance in which a pair of mainsprings drive a triple-axis tourbillon that houses a pair of balance wheels and escapements. Power is distributed to each set of gears and escapement via a differential, ensuring both systems are operating independently from each other in order for the vibrational effects of resonance to occur solely via a shared cage with a pillar-type construction. Now he has gone on to introduce a simpler, more practical but no less fascinating resonance watch, simply called La Resonance.
Though the watch has a conventionally round case, the movement is vividly airy in construction, which intriguingly, creates a false sense of simplicity, so much so that a cursory glance at La Resonance might leave you thinking it’s a rather straightforward time-only watch. But in fact, not only is it a resonance watch, its format differs from earlier examples of such timepieces in the market. It incorporates a differential that directs power from a pair of mainsprings to each of the separate gear trains. And crucially, it introduces convincing solutions to ensure that resonance occurs more readily. The balances are mounted on a shared balance bridge while the hairsprings share a common stud holder to maximize energy transmission and strengthen the coupling force.
A Novel Architecture
One of the most immediately striking qualities of the watch is its highly visible movement, aided in part by an openworked dial and a unibody case with a large sapphire window along its flanks. The crown has been relegated to the nine o’clock position, allowing the right side of the case band to be fitted with a sapphire crystal for the double balances to be admired in motion.
The movement itself has an unconventional construction. It was designed without a base plate. This flies in the face of almost every other resonance watch in the market in which a shared base plate is a prerequisite for resonance to occur. The gears in La Resonance are instead held in place by 13 lean titanium bridges and 30 pillars, leaving the entire layout of the going train in plain sight. This creates the effect of weightlessness, which is bolstered by a lightweight titanium case that measures 39mm wide and 11mm high. The gears including the motion works are magnificently large, which in addition to providing smoother transmission, offers an expansive view that invites inquiry.
Providing a power reserve of 100 hours, the mainspring barrels are installed in a parallel configuration to provide high torque to an impressively large differential in the middle. Notably, because of the diameter of the gears and the space necessary to ensure secure footings for the bridges, the layout of the gear train is rather unusual. The second wheel is located above the barrels while the third wheel, where the differential is located, is slightly off centred. As a result, the second wheel drives the minute wheel on the dial side, which is a deviation from a standard movement where the second wheel drives the cannon pinion directly.
Sandwiched between two large third wheels is the differential, which is made up of a system of planetary gears consisting 55 parts. A gear above the differential transmits the equalised force to a pair of auxiliary wheels which in turn drives the seconds hand of the watch in the middle. At the same time, each third wheel transmits the output produced by the differential to the respective fourth wheels, ensuring that the balances keep pace relative to each other and are poised for synchronization.
Notably, all the concave pillars in the movement have been black polished while the long axles for the fourth wheels and escape wheels have been facetted. All 11 wheels in the movement have a brushed top surface with polished, bevelled spokes. In fact, the amount of anglage in the movement totals 12 feet and equates to approximately eight weeks’ worth of work.
The Pursuit of Resonance
The basis for the pursuit of resonance in watches is relatively straightforward. When the vibrations of two balance wheels sync up, any deviations in rate one accrues tends to be cancelled out by the other, thereby producing an averaged, more stable rate than either one can achieve in isolation. However, in practice, this is a lot harder to achieve as the synchronicity of two oscillators is dependent on proximity and the transfer of vibrations from the hairspring to the cock to the shared main plate – a process that can be influenced by myriad factors. The rates of two balances, for instance, needs to be adjusted as close to each other as possible while being free sprung, as having an index regulator reduces the effect of the vibration transmitted from the hairspring to the cock and main plate.
The phenomenon of resonance was first discovered in 1665 by the great Dutch scientist Christiaan Huygens who saw that two of his pendulum clocks, which were suspended from a common beam, tended to oscillate in synchronicity. This phenomenon was later researched and built upon by both Antide Janvier and Abraham-Louis Breguet, who were noted for having made clocks with double pendulum systems, each driven independently. Breguet was one of the first watchmakers to have successfully achieved the effect of resonance in pocket watches. Crucially, having tested the phenomenon in a vacuum, he also discovered that air resistance had minimal impact on synchronicity. Ultimately, the key to resonance lies in the coupling structure, through which energy is transferred in the form of mechanical vibrations.
The very first wristwatch to achieve a resonance effect was the F.P. Journe Chronomètre à Résonance, launched in 2000. The watch was built based on Breguet’s findings and relied on the transfer of vibrations from the balances to the cocks to the main plate. Since then, a handful of other resonance watches has been introduced in the market, most notably Armin Strom. The brand has gone a step further in enhancing the coupling forces between both balances by introducing a patented clutch spring that connects both hairsprings directly, effectively inducing the phenomenon.
While the Vianney Halter La Resonance was built without a main plate, the balances are mounted in a co-axial configuration with a shared bridge connecting them directly. On top of that, both hairsprings share a common stud holder to strengthen the transfer of vibrations. As the hairspring winds and unwinds, a small amount of vibrational energy is transmitted from one stud to the next, directly influencing each other. Both solutions are convincingly reliable methods to improve pairing forces and ensure that resonance takes place fluidly. When in unison, the two balances can oscillate in the same or opposite direction depending on the position of the escapement when the watch is started.
The lightweight design of the watch – from the case to the architecture of the movement to the outsized wheels – is extremely compelling in conception, execution and effect, as are the technical solutions to improving resonance.
At 235,000 CHF, the Vianney Halter La Resonance is double the price of the F.P. Journe Chronomètre à Résonance and the equivalent from Armin Strom. With that said, the movement is complex in both construction and finish. In fact, its architecture is particularly unique for a resonance watch, which in turn results in the theoretically superior solution of having a shared balance platform bridge and stud holder to enhance the phenomenon of resonance.
Due to the labour-intensive nature of each piece, only seven examples will be made a year. At the time of writing, the first seven pieces have already been spoken for.
Vianney Halter La Resonance
Movement: Manual-winding with two barrels; 100-hour power reserve; 3 Hz (21,600 vph)
Functions: Hours, minutes, central seconds; acoustic resonance
Case: 39mm by 11mm; Titanium with sapphire window; Water-resistant to 30m
Strap: Crocodile with titanium folding clasp
Price: 235,000 CHF
Availability: 7 pieces per year