Chronomètre FB 1R.6-1Reference# Chronomètre FB 1R.6-1
- Limited Edition: 20 pieces
- Case: carburised stainless steel
- Size: 44mm
- Movement: hand-wound manufacture caliber FB-T.FC.R
- Function: tourbillon, power reserve, suspended fusée and chain constant-force transmission regulation
- Power Reserve: approximately 53 hours
- Water Resistance: 30m
- Dial: black, satin-brushed by hand
- Caseback: sapphire crystal
- Strap/Bracelet: hand-sewn alligator leather
With its original regulator-type display and its ultra-resistant carburised stainless steel case, the Chronomètre FB-1R.6-1 enriches the Ferdinand Berthoud collection. This new presentation radically transforms an exceptional timepiece whose complications, together with the quality of its construction and production, remain true to their underlying philosophy. Its FB-T.FC.R tourbillon caliber with fusee-and-chain transmission can be admired through a sapphire crystal caseback and two lateral portholes, offering a unique view inside this outstanding chronometer.
Like the previous editions of the Chronomètre FB 1, its movement is equipped with horological complications inspired by the scientific instruments represented by Ferdinand Berthoud’s marine chronometers. A rare and unusual-looking timepiece, the Chronomètre Ferdinand Berthoud FB 1R.6-1 is a comprehensive horological work, issued in a 20-piece limited edition intended for discerning and passionate collectors.
The Chronomètre Ferdinand Berthoud FB 1R.6-1 adds some unusual details and a unique presentation to the aesthetic and technical characteristics of the previous versions. It is still a 44mm watch, featuring a less than 14mm-thick case that sits naturally and comfortably on the wrist. It is composed of a steel cylinder housing the movement. The molecular structure of this steel has been reinforced by a thermo-chemical process involving the diffusion of vapor-phase carbon, thereby guaranteeing an exceptional surface hardness of 1,200 Vickers and making it extremely robust. It is also exceptionally corrosion-resistant and biocompatible.
The case features two octagonal-shaped stainless steel side pieces, giving it a characteristic shape including two lateral portholes at 2 and 11 o’clock – providing a chance to admire the chain-and-fusee mechanism in action. These two openings are complemented by a screw-down stainless steel caseback fitted with glare-proofed sapphire crystal enabling observers to appreciate the high-quality finishing lavished on the FB-T.FC-R movement. The knurled 9mm-diameter stainless steel crown bearing a black ceramic medallion ensures smooth winding of the movement endowed with a 53-hour power reserve.
The novel construction of the Chronomètre Ferdinand Berthoud IR.6-1 sets it apart from all existing regulator-type displays. Instead of featuring a high-up opening providing a view of the tourbillon and the fourth wheel (driving the seconds) as on previous versions, the Chronomètre Ferdinand Berthoud FB 1R.6-1 has a mostly solid dial. The latter is in fact the rear side of the complication plate that provides the regulator-type display.
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 center of the finely chamfered, bead-blasted and black rhodium-plated minutes counter, the third aperture displays a hand-engraved “pyramid” motif inspired by an openworked Ferdinand Berthoud astronomical clock belonging to the L.U.CEUM collection. 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. Finally, the nature and provenance of the Chronomètre Ferdinand Berthoud FB 1R.6-1 can be read off on this large dial, engraved with the inscription “Chronomètre Val-de-Travers Suisse”. More than merely representing a signature or an appellation of origin, it proudly proclaims the model’s identity.
A patent has been filed for the extremely sophisticated power-reserve indication mechanism. Visible through a cut-out in the half-bridge on the caseback 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 reveled in exploring solutions resolutely off the beaten track.