GPHG: Chronometry Finalists

GHPG Chronometry finalists

So many watches, so many wonderful posts! We’ve had an in-depth look at three of the Ladies‘, Ladies’ Complication, Men’ and Mens’ Complication categories in the watch industry Oscars: the Grand Prix Horologie De Genève. Today’s post offers pics and edited copy from three of the GPHG Chronometry Finalists . . .

Originally created in 2014 as the Tourbillon Watch Prize for watches featuring a tourbillon, renamed Chronometry in 2018 to include other special timekeeping features. So now you know. Here’s three worth watching, so to speak.

GPHG Chronometry Finalist

TTR3 Blue Equalizer Frequencies – 1’200’000 CHF ($1,212,231.48)

This unique watch in 18 ct white gold contains 233 saphirs of over 24 ct in total, in rare blue royal, baguette-cut, invisible mounting, with three solitary trillion saphirs floating on the dial, beside the three tourbillons. The Tourbillon of Tourbillons movement, a core component for this brand, is the result of a collaboration between him and his son Florian that is at the heart of this brilliant watch.

Associating three tourbillons on a revolving plate gives the timepiece unmatched regularity, thanks to  its triple differential. Each tourbillon completes one rotation per minute, at a faster rhythm than the plate, which completes six rotations per hour (one rotation every ten minutes).

GPH Chronometry finalist in blue

The speed at which the tourbillons rotate is accelerated by this double revolution. They are placed equidistant from the centre of the plate, with their respective axes forming an equilateral triangle. Isochronism is enhanced by the fact that the three cages rotate on different axes and at variable speeds.

This differential is unique both in its conception and the variety of tasks it performs. It must distribute constant energy from the double-barrel to the three tourbillons through the centre of the watch, without affecting the axis of the hands; react if one the tourbillon stops working; and correct any variations in frequency. It contains the tiniest ball-bearing in the world, barely 1.6mm in diameter!

Antoine Preziuso GPHG entry

The closeness of the three independent regulating tourbillons – and their positions on the plate – enable them to resonate, and naturally adopt an identical frequency through a phenomenon known as “synchronism”. When the tourbillons start to resonate, their amplitude increases significantly – in a manner perceptible to the naked eye. The system as a whole thus forms a single revolutionary regulator, vibrating at a perfectly stable frequency of 3 Hz.

The generously sized 47 mm case has a sapphire back that allows the beholder to admire all the beauty and complexity of the patented movement, with three tourbillons to the front connected by a triple-differential gear rotating around each other in 60 seconds while the plate completes six rotations each hour.

OUR TAKE: Holy shit. If ever a watch deserved to be one of the GPHG Chronometry finalists, this is it.

GPHG Chronometry finalist Chronometre Ferdinand Berthoud FB 1R.6-1 

Chronometre Ferdinand Berthoud FB 1R.6-1 – 230’000 CHF ($232,215.34)

Inspired by the marine chronometer No. 7 that Ferdinand Berthoud produced in 1767, the construction and the regulator-type display of the Chronomètre Ferdinand Berthoud FB 1R.6-1 overturn traditions. Composed of a black rhodium-plated nickel silver regulator plate satin-brushed by hand, the dial features three openings: one for the hours (at 2 o’clock), another for the minutes (at 12 o’clock) and a third for the power reserve (at 10 o’clock).

The FB-T.FC.R calibre, with its pillar-type architecture, features a direct-drive centre seconds tourbillon whose constant force is provided by a fusee-and-chain transmission mechanism incorporating a satellite differential gear and Maltese cross stopwork device. Continuing the quest of precision inherited from Ferdinand Berthoud, this COSC-certified timepiece is available as a 20-piece limited edition in carburised stainless steel.

It is made of nickel silver, vertically satin-brushed by hand and black rhodium-plated. Of the three small apertures, the first serves to show the hours, offset at 2 o’clock and appearing on a glare-proofed sapphire crystal disc bearing transferred Arabic numerals striking a pleasing contrast with a white background.

The second opening features an original power-reserve display mechanism, distinguished by a large dial cut-out revealing part of the finely sandblasted and black rhodium-plated mainplate. Located in the centre of the minutes counter at 12 o’clock, the third aperture displays wheels and movement decoration.

Meanwhile, the seconds appear around the rim of the dial on a flat inner bezel ring made of black rhodium-plated, bead-blasted and chamfered nickel silver.

The FB-T.FC.R calibre is built according to a unique architectural concept. This hand-wound movement features 18 nickel silver bridges framed by polished titanium pillars surrounding the mechanical organs. This construction is typical of 18th century marine chronometers. The architectural approach is picked up in the design of all the components, and especially in the symmetrical equilibrium of the movement.

The distinctive nature of the FB-T.FC.R calibre lies in its inverted upside-down barrel and fusee, and particularly in the fact that both elements are suspended, meaning held on only one side. A patent has been filed for this construction which saves precious millimetres. At 9.89 mm thick, the movement of the Chronomètre Ferdinand Berthoud FB 1R.6-1 thus remains extremely thin for its category despite the regulator-type display and the new power-reserve indication.

This movement is one of the rare examples to feature a fusee-and-chain transmission, which is the oldest historical solution developed to ensure constant force for the escapement. This system acts like an automatic gear box, with the torque delivered by the barrel varying according to the level of winding.

When the movement is fully wound (53 hours of power reserve), the chain is entirely coiled around the small end of the fusee and the barrel spring is at maximum power. This force dwindles in the course of time, as the chain coils around the drum, moving from the small to the large end of the spindle-shaped fusee. The variation in the diameter of the fusee compensates for the reduction of the mainspring torque. The escapement thus receives constant energy, thereby equalling out the amplitude of the balance wheel and thereby enhancing the movement’s timekeeping precision.

GPHG Chronometry finalist from Chronometre Ferdinand Berthoud


Teamed with the fourth (seconds) wheel and pinion, the tourbillon of Calibre FB-T.FC-R comprises 67 components assembled within a titanium carriage measuring 16.55 mm in diameter, and fixed to a perfectly hand-polished and chamfered arrow-shaped steel arch whose tip points towards the space between the barrel and the fusee. To poise the escapement’s unbalance, two 18-carat gold inertia-blocks ensure the uniform spread of the weights of this large-size tourbillon.

This tourbillon contributes to earning Calibre FB-T.FC.R its chronometer title awarded by the Swiss Official Chronometer Testing Institute (COSC). One particular characteristic makes the tourbillon extremely distinctive: although it performs one rotation per minute, it does not indicate the seconds, since the Chronomètre Ferdinand Berthoud FB 1R.6-1 is one of the rare tourbillons to have a central sweep-seconds hand. Extremely long, slim and made of gilded bronze, the latter moves with remarkable accuracy and in a remarkable stable manner.


Limited to 20 pieces, the FB 1R.6-1 model features a 44 mm-diameter case, made of carburised stainless steel. The molecular structure of this steel has been reinforced by a thermo-chemical process involving the diffusion of vapour-phase carbon, thereby guaranteeing an exceptional surface hardness of 1200 Vickers and making it extremely robust. It is also exceptionally corrosion-resistant and biocompatible.

The choice of this type of steel, currently used in the aerospace industry, is a nod to the maritime expeditions achieved using the Marine Chronometers produced by Ferdinand Berthoud in the 18th century and which required the use of extremely sturdy materials.

The knurled 9mm-diameter stainless steel crown bearing a black ceramic medallion ensures smooth winding of the movement.

Ferdinand Berthoud case back


A patent has been filed for the extremely sophisticated power-reserve indication mechanism. Visible through a cut-out in the half-bridge on the case-back side, a truncated cone moves up and down along an arbor connected to the barrel. This suspended cone is topped by a feeler spindle in the form of a mobile arm tipped with a watch jewel. The latter’s position on the cone reflects the barrel’s state of wind.

The feeler spindle in turn transmits the quantity of energy accumulated by the mainspring to a set of finely chamfered and rhodium-plated flat levers visible through a cut-out in the regulator plate. Its role is to amplify the displacement of the power-reserve hand. A spiral spring placed at the far end of its travel exercises a force on the base of the power-reserve hand. This spring serves to compensate for the play between the various components of this mechanism and to display the power reserve with peerless precision.

A number of complex mathematical calculations and various tests served to fine-tune the geometry of this spring, made from a nickel-phosphorous alloy in order to guarantee the concentric deployment of the coils in all states of winding and unwinding, and thereby to avoid any unattractive distortion that might also be detrimental to the smooth running of the mechanism. This ingenious device is imbued with the experimental spirit of Ferdinand Berthoud himself, who revelled in exploring solutions resolutely off the beaten track.

OUR TAKE: Not the prettiest watch you’ll ever see (not that you’ll ever see it), but bloody hell!

GPHG Chronometry finalist ARMIN STROM Latest Resonanceh3>ARMIN STROM Pure Resonance – 62’000 CHF ($$63,606.81)

The goal of the Pure Resonance has not changed: to display the interesting resonant balances while improving overall precision. To this end, brand director Claude Greisler has removed the twin seconds flyback mechanism of Caliber ARF15, replacing them with one clear-cut subsidiary seconds subdial.

The reason for this watch’s improved chronometry can be found in the straightforward approach to the movement: the fewer functions a timepiece must perform, the better it can concentrate on accuracy. In other words, with no superfluous functions this watch can focus fully on precisely providing the time. The time displays receive their portioned energy from the lower regulator, while the upper regulator remains in place to create resonance.

This conceptual forthrightness is reflected in the design of the movement: state-of-the-art basic Caliber ARF16 showcases the resonant regulators and playful resonance clutch spring. New bridges are decorated with succinct, eye-catching côtes de Genève, applied for the first time at ARMIN STROM in straight lines. “The purpose of redesigning the movement’s architecture was clarity, thereby putting focus on the resonance assembly and accuracy,” says Greisler.


Classic Size

The outward design of this new Pure Resonance perfectly reflects the purity of Caliber ARF16. It is housed in a slimmer 42 mm 18-karat rose gold case (1.4 mm smaller than the original version) with reduced lugs and crown and practically no bezel, though the characteristic lip at 6 o’clock remains – an homage to the ability of ARMIN STROM to customize any of its watches as well as to founder Armin Strom, who offered this space to clients for personal engraving (and it can still be used for that).

The latest version Pure Resonance looks and acts just like a “normal” three-handed watch. And this remains in line with the philosophy of ARMIN STROM as a brand: just good, proprietary mechanics presented in an impeccably finished and interesting way. The “Pure Resonance heralds a new era at ARMIN STROM,” owner Serge Michel promises.

OUR TAKE: A subtle choice that won’t make the final cut, but nice to look at, n’est-ce pas?

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