The New Chronomètre FB 3SPC by Ferdinand Berthoud with a Cylindrical Hairspring

The Calibre FB-SPC of the new Chronomètre FB 3SPC by Chronométrie Ferdinand Berthoud takes evident inspiration from the No. 26 decimal watch by using such a cylindrical hairspring and giving it pride of place in a void in the mainplate, visible on the dial at 9 o’clock.
 

The sight of the pulsating hairspring (with hand-crafted Berthoud terminal curves) and oscillating, 3Hz variable-inertia balance wheel (with four fine-adjustment screws and 12 load screws), as well as the pivoting Swiss lever and rotating escape wheel is an absolute joy to behold.

This regulating organ’s superb timekeeping performance was only made possible thanks to considerable efforts by the team of régleurs at Chronométrie Ferdinand Berthoud.

They needed two years to perfect the necessary adjustments before being granted ISO 3159 standard chronometer certification by COSC, representing a first for such a movement. In fact, they even ensured it was chronometer-worthy over 48 hours of testing (rather than COSC’s 24 hours) and that it would stand up to the more real-life conditions simulated by the Fleuritest.
 

The few other cylindrical hairsprings that do exist in modern watchmaking are usually paired with a tourbillon to improve the timing rate by averaging out positional errors due to gravity. But in the case of the Chronomètre FB 3SPC there is no tourbillon to lend a hand, and so the hairspring is left to its own devices – and the expertise of the brand’s regulating watchmakers – to combat gravity.
 

And with precise timekeeping should, of course, come precise time-setting, and the hand-wound FB 3SPC duly has a crown-activated stop-seconds mechanism.

Elsewhere on the dial, we have the pared-down indications: Central hours and minutes, a three-day power-reserve indicator at 2 o’clock, and small seconds at 6 o’clock. Architecturally, there are a number of nods to classic Berthoud creations by both uncle and nephew.
 

The stepped balance bridge, for example, is inspired by Ferdinand Berthoud’s No. 3 astronomical watch. Meanwhile, at 12 o’clock, the curved bridge for the slip-spring barrel evokes a bridge on the No. 2575 quarter-repeater watch made by Louis Berthoud.
 

Additionally, the facetted, skeletonized, and open-tipped 18k gold hands are influenced by a 1785 Ferdinand Berthoud astronomical regulator that is now part of Chronométrie Ferdinand Berthoud’s collection of heritage objects that also includes the No. 26 decimal watch that is so influential here.
 

The rest of the dial is left intentionally open to let the viewer admire the arrangement and aesthetics of the movement components, especially their hand-done decoration.

Indeed, more than 100 hours are devoted to hand-finishing the 230-component movement. The mainplate and 16 bridges (six on the dial side and ten on the back, all made with German silver) are hand-frosted on their flat surfaces, while the bevels on the surface edges are created and polished by hand.
 

Each beveling specialist at Chronométrie Ferdinand Berthoud has their own idiosyncratic style. Therefore, to create a consistent aesthetic throughout the whole movement, it was decided that each calibre would be assigned a single decorator.

The Chronomètre FB 3SPC hasn’t just seen Chronométrie Ferdinand Berthoud develop a new movement; it also has a new case. The round 18k gold housing does replicate some features of the company’s round cases in the past, including screwed lugs and caseband porthole that here allows for lateral views of the contracting and expanding hairspring.
 

But crucially, at 42.3mm by 9.43mm, this is the thinnest and arguably most wearable timepiece to date. Plus, as part of Chopard Group, the brand can make use of Chopard’s Geneva foundry for sourcing responsibly-mined gold.
 

Finally, the sapphire crystals with anti-reflective coating on the dial side and the back are slightly domed. And while you are highly unlikely to jump in the sea or pool with this beauty on your wrist, the 3-bar case gives decent water resistance for such a high-end watch.

Chronométrie Ferdinand Berthoud kicks off the start of its Chronomètre FB 3SPC by releasing two editions of it: the Ref. FB 3SPC in 18k white gold with a 2N gilded movement, and the Ref. FB 3SPC.2 in 18k red gold with a black rhodium-treated movement components. Each is paired with an alligator leather strap that has a pin buckle in the same material as the case.
 

The brand makes only a few dozen watches per year, so production of the new FB 3SPC – priced at CHF 140,000, including Swiss taxes – will be limited to a maximum of 25 pieces per year across both case materials.
 

For more information, please visit the Chronométrie Ferdinand Berthoud website.

(Photography by Pierre Vogel)