An octagonal case, a tourbillon movement with fusee-and-chain transmission and a pillar-based construction: the Chronomètre FB 1 has played a major role in defining the identity of Chronométrie Ferdinand Berthoud.
Calibre FB-T.FC powering this model is now preparing to take a last bow, in the form of a final 38-piece edition presented for the first time with a round case: the Chronomètre FB 2T.
Even before the inauguration of the Manufacture, the President of Chronométrie Ferdinand Berthoud, Karl-Friedrich Scheufele, had a clear objective: to offer contemporary creations pursuing the work of Ferdinand Berthoud. This led to the 2015 presentation of the Chronomètre FB 1, a wristwatch such as the great Master Watchmaker might have conceived it today.
This first collection offers an alternative vision of Haute Horlogerie to an audience of discerning collectors: timepieces distinguished by excellence, powered by a 100% Manufacture movement, chronometer-certified, equipped with a tourbillon and fusee-and-chain transmission, as well as based on a pillar-type construction. The Chronomètre FB 1.1 with its octagonal case was enthusiastically welcomed by professionals who awarded it the “Aiguille d'Or”, the supreme best-in-show distinction of the Grand Prix d’Horlogerie de Genève, just one year after its launch.
Eight years later, the final 38 examples of this calibre will be presented for the first time in a round case, giving life to the Chronomètre FB 2T – Final Edition. An exceptional collection driven by a movement whose entire kinematic chain has been designed as an authentic watchmaking experience.
THE FIRST CONTACT: WINDING
The first physical contact with a mechanical watch is when it is wound. Traditionally, this consists of manually winding the barrel. Equipped with a constant-force device known as fusee-and-chain transmission, Calibre FB-T.FC features a unique modus operandi, as winding is not done via the barrel, but by means of a differential placed in the centre of the fusee. This mechanism serves to reduce the force required for winding.
Seventy turns of the crown are thus required to fully arm the mainspring, smoothly and without the slightest effort. Its 9 mm diameter makes the crown easy to grip. It is also equipped with a safety device to protect the movement from excessive winding. A dynamometric spring hidden in the heart of this so-called "disengageable" crown makes it possible to limit the torque transmitted to the motor organ. When the tension required to wind the movement exceeds the permitted values, the dynamometric spring disengages, thus preventing the crown from driving the winding pinion. This prevents excessive winding which would damage the movement.
The engineers at Chronométrie Ferdinand Berthoud devote particular attention to winding when developing movements. It is the starting point that daily embodies the intimate interaction between a collector and their watch.
THE MOTOR ORGAN: THE CHOICE OF FUSEE-AND-CHAIN TRANSMISSION
Activating the crown triggers the rest of the kinematic chain and invites observers to discover the various developments enabling each movement to be certified as a "Chronometer" by the Official Swiss Chronometer Testing Institute (COSC). With a mean daily rate of between -1 and +2 second(s) per day, the chronometric (precision timing) performance of Ferdinand Berthoud watches far surpasses the standards required by the COSC. To achieve such precision, the driving force of Calibre FB-T.FC calibre consists of an inverted fusee and a barrel – both suspended and linked by a chain ensuring constant force throughout the entire 53-hour power reserve.
Located at the top of the barrel, a Maltese Cross stopwork device mechanically limits the operating range of the mainspring where its torque is most constant. Although the barrel can potentially perform eight full revolutions itself, the Maltese Cross allows only six, marked by the six teeth on its profile. The last two indentations on the Maltese Cross prevent the mainspring from delivering too much energy to the gear train (just after complete winding) or too little (at the end of the power reserve).
THE ESCAPEMENT: A TOURBILLON WITH CENTRAL SECONDS
During the entire 53-hour power reserve, this constant energy is delivered to the escapement, a tourbillon with central seconds, for which a patent has been filed. Positioned at 6 o'clock, the tourbillon carriage engages directly with the seconds (fourth) wheel thanks to a wheel located on its axis whose diameter and properties are identical to those of the seconds. The two wheels thus make a complete rotation in 60 seconds: the seconds (fourth) wheel in a clockwise direction and the tourbillon wheel counter-clockwise.
This particular construction optimises the flow of energy transmission by keeping the required number of gears to a minimum and likewise reducing the risk of irregularities due to friction. A long central wire-shaped hand thus displays the seconds accurately and without any stuttering of the hand – very much like the Marine Clocks produced by the Master Watchmaker who dedicated his life to the quest for precision.
POWER-RESERVE INDICATION: AN UNPRECEDENTED MECHANISM
The power-reserve display of calibre FB-T.FC is based on a patented process that is as judicious as it is elegant.
Directly linked to the barrel by a large-diameter driving wheel, the mechanism uses the movement of arming and disarming the mainspring to move a cone up and down a threaded central arbor attached to the mainplate.
A feeler tipped with a ruby roller end measures the upward and downward movement of the cone. When the movement is fully armed, the cone is at the top of the threaded arbor and the feeler arm therefore rests at the base of the cone (its widest diameter). As the movement is disarmed, the cone rotates and moves down the threaded arbor. The diameter of the cone at the feeler decreases and the feeler moves closer to the axis of the threaded arbor.
The feeler arm rotates by about 15°, as does the rack below it, which is on the same axis. It is the latter that transmits the movement’s power-reserve level to the hand on the dial side.
ARCHITECTURE: A UNIQUE PILLAR-BASED CONSTRUCTION
These innovations take place within an architecture that illustrates Chronométrie Ferdinand Berthoud's desire to offer contemporary collections that continue the work of Ferdinand Berthoud. By adopting a vertical construction supported by six pillars, the workshop pays tribute to the Marine Clocks designed by the Master Watchmaker, while providing the FB-T.FC movement with scope for technical and aesthetic expression that is totally unprecedented in contemporary Haute Horlogerie.
AN INVITATION TO EXPERIENCE BESPOKE: 38 CUSTOMISABLE MOVEMENTS
38 years after obtaining his title of Master Horologist, Ferdinand Berthoud published the Traité des montres à Longitudes in which he summarised his research on marine clocks. This step reflects the maestro’s characteristic experimental approach as well as his determination to pass on his expertise. In reference to this achievement, the last 38 examples of Calibre FB-T.FC-2 will be dedicated to this Chronometer FB 2T collection. They are distinguished by three bevelled and engraved sapphire half-bridges, supported by polished steel pillars providing a chance to admire the movement’s main organs, as well as an understated hand-sandblasted finish resulting in a particularly modern appearance.
Three versions will be offered by the Maison: FB 2T.2 in 18-carat rose gold with a black satin-brushed dial; FB 2T.2-1 in 18-carat rose gold with a ruthenium satin-brushed dial; and FB 2T.1 in 18-carat white gold with a blue satin-brushed dial.
These three references are sources of inspiration for collectors who will have the opportunity, for this "Final Edition", to create their own customised timepiece by choosing the case material, the colour and the finishing of the dial and the leather strap. There is however a limit with regard to the case shape: this FB 2T collection is offered exclusively with the round case presented in 2020 with the FB 2RE Remontoir d'Egalité collection.