Ferdinand Berthoud Chronomètre FB RSM Watch Review
The Ferdinand Berthoud Chronomètre FB RSM perpetuates the esteemed reputation of the high-end Maison and its no-compromise approach to watchmaking. A tourbillon with fusee and chain transmission, Maltese cross stopwork, variable inertia balance and hand-crafted Philips outer terminal curve, all contribute to the model’s extraordinary chronometric performance. In this instance, the luxury marque, clearly keen to develop future talent, has engaged a young watchmaker from the University of Neuchâtel to participate in the development of the movement, the FB-T.FC-RSM. Interestingly, the movement has an independent deadbeat seconds and a stop-seconds mechanism.
Ferdinand Berthoud
There’s a bit of a tradition of bright apprentices being given opportunities to work at Ferdinand Berthoud’s atelier. Despite only employing 41 souls, the brand has quite the reputation for bringing on talent. Berthoud was himself only 26 when he became a master watchmaker and the paint was barely dry on the nameplate of his Paris workshop when he took on his first apprentice in the mid-1700s. He must have been a good boss as the lad stayed for eight years. His next apprentice, Jacques-Vincent Martin, stayed for 20. Things have been going well for the young ‘uns ever since.
Ferdinand Berthoud Chronomètre FB RSM – the apprentice
Ferdinand Berthoud’s current apprentice is already proving his ability by doing remarkable things at an age when the only remarkable thing most of us did was make it unhungover to a 9 am lecture. For example, this new watch’s tourbillon carriage is just 16.5 mm across. That’s 1.5mm smaller in diameter than a current United Kingdom 5-pence piece, a casual bit of pocket change. Now imagine trying to shoehorn 67 parts, some made of titanium, some of gold, some copper beryllium into a tourbillon carriage (surely more of a kei car than a carriage) that tiny. Now imagine that a good percentage of those need to move – absolutely precisely – for the entire lifetime of a watch. And now imagine doing it as an apprentice in your early 20s. That’s what one of Ferdinand Berthoud’s lads has been getting up to while helping to create the Chronomètre FB RSM.
Now, think back to what you were doing in your twenties. Depressing, isn’t it?
Ferdinand Berthoud marine chronometers
With its heritage of building marine chronometers, Ferdinand Berthoud has a penchant for making wonderful horological creations. The genetics of this new watch are clear – the Ferdinand Berthoud Chronomètre FB RSM can trace its family tree back to the Berthoud Marine Clock No. 8, known as HM-8, (Horologe Marine No. 8) from 1768. This latter clock was a marine regulator, so the most prominent part of the display was the second hand. That’s because it was essential when setting time at sea, that the mariner knew the time to the exact second. Incorrectly setting the time by just a few seconds could result in a ship being miles off course in just a few days.
The large second hand ruled the dial with minutes on a subsidiary dial and hours tucked away on a tiny rotating disc in an offset display. Clearly, if you didn’t know what hour it was you probably had bigger problems, like your impending court martial for navigational incompetence.
Ferdinand Berthoud Chronomètre FB RSM – deadbeat seconds
The second hand ticked like a quartz, one beat per second, because it’s more precise that way (you know exactly when a particular second starts and ends). To do this, the movement housed a deadbeat mechanism (more later on that). The balance spring itself was thermocompensated with the balance carrying small weights on its circumference.
The Ferdinand Berthoud Chronomètre FB RSM miniaturises the engineering and design concepts of the HM-8, making it suitable for the wrist. The movement is worth a look on its own. Ferdinand Berthoud is making just twenty of them. The idea is that buyers can then specify their own case shape (octagonal or round) as well as the dial execution.
Ferdinand Berthoud Chronomètre FB RSM – Calibre FB-T.FC.RSM
The Calibre FB-T.FC.RSM movement uses a pillar construction (rather than movement plates being fixed directly together). This means the case houses 18 nickel-silver half bridges held together with six stylised polished steel pillars. This has enabled Ferdinand Berthoud to reduce the thickness of the movement to under 10mm. Think about that for one of those precise seconds. A movement slimmer than 10mm – that’s around six 5p pieces stacked on top of each other – despite there being a fusee mechanism, a deadbeat seconds and 1,169 components packed into the 44mm x14mm case. OK, it’s not exactly a feuille d’or, but just reflect on the sheer amount of watchmaking engineering it’s crammed in. It’s quite remarkable. Using pillars also means the barrel and fusee can be suspended.
Being a regulator, most of the visual interest is on the movement side. It’s not that the dial side is ugly – far from it – but there’s more going on out back. That’s where you can see the tourbillon, the fusee and the barrel doing their respective things.
Ferdinand Berthoud Chronomètre FB RSM – constant-force tourbillon regulator
What you’re looking at when you carefully turn the watch over is all about power transmission. And clever power transmission at that. Remember that one-beat-per-second second hand? That ‘dead seconds’ complication makes life a lot more complicated than a simple smooth seconds tick, especially when the watch you’re making needs to meet chronometer specifications. Getting the second hand to stop and re-start takes three separate steps. First, you need to bring the whole gear train to a halt. Then you need to store the torque it’s producing while it’s stopped and then you need to release it again precisely at the end of the second. That’s hard enough. But this is a chronometer with a constant force movement, which makes it an utter nightmare. That’s because you’re constantly interrupting the linearity of the torque. It’s why most dead seconds movements get all anxious about chronometric trials and plead a headache.
In this case, our Neuchâtel apprentice rides to the rescue. Having immersed himself in dusty ancient watch patents and old clock archives, he has worked on perfecting the movement’s Tourbillon Régulateur à Force Constante (constant-force tourbillon regulator). In short, this enables the movement to stop, control and restart without mucking up its precision while happily keep ticking at 21,600 beats per hour.
Key to this is the fusee mechanism. It uses an almost cotton-thin chain, 285 mm long and made from 790 components, to equalise the changes in torque from the mainspring by slowly unwinding around a cone-shaped pulley. This keeps power running constantly (in the horological sense) to the tourbillon.
Ferdinand Berthoud Chronomètre FB RSM – the dial
The dial side may not be as visually exciting (to be fair, that would take some doing), but there’s still plenty of loveliness going on. There’s that disc hours display at 2, the pointer minute display at 12 with the deadbeat seconds taking pride of place in the centre along with the stop-seconds device and a power reserve indicator.
The 18-carat gold dial is hand-engraved with the “No. 8” inscription taken from the original No. 8 Marine Clock. There’s a neat touch in the way you can see the deadbeat seconds mechanism working away through a ‘figure-eight-shaped aperture at 9 o’clock’. The minutes sundial is openworked, sandblasted and silver-toned with the seconds around the edge of the bezel on its own track. Hours are up at 2 on a partly concealed sapphire disc.
Ferdinand Berthoud Chronomètre FB RSM – a modern-day ‘No.8’
The hands have also been carefully considered. Although it looks like blued steel, the star of the show second hand is actually titanium (it’s much lighter, so needs less power to push around the dial) and CVD (chemical vapour deposition) treated. The minute hand is an unusual skeleton dagger that echoes the hands on the FB 2RE, but, despite the blue CVD, is 18-carat gold underneath. The hour pointer (which has no need to move as the sapphire disc it points to does all the hard slog) is blue CVD steel. Finally, under the display caseback, the arrow-type power-reserve hand is again presented in 18-carat gold with blue CVD treatment.
A little ironically (in a good way) for a watch that is all about precision, uniformity and regulation, Ferdinand Berthoud is happy to give you free rein on its design. I’ve set out one option above, but there are more. You can have a round case or an octagonal one, have FB’s craftsmen make it from steel, platinum, white or rose gold and choose the way you’d like the main dial plate and hands finished.
Most people graduate with a student loan, a selection of hangover cures and a dissertation no one will ever read. One young watchmaker from the University of Neuchâtel, on the other hand, will walk out of the college gates with a world-class complicated watch movement already under his or her belt. One imagines you won’t see them down at the job centre.
Further reading
https://www.ferdinandberthoud.ch/
Technical specifications
- Model: Ferdinand Berthoud Chronomètre FB RSM
- Case: Round case in 18-carat white gold or 18-carat rose gold (two variants); fitted with transparent sapphire porthole, diameter 44 mm height 14.30 mm; water resistance 3 ATM (30 m); sapphire crystal to the front and exhibition case back.
- Functions: Disc-type hours display at 2 o’clock; pointer-type minutes display at 12 o’clock; deadbeat seconds in the centre; stop-seconds device and power reserve
- Movement: Calibre FB-T.FC.RSM; hand-wound movement; frequency 21,600 vph (3 Hz); 60 jewels; power reserve 53 hours
- Strap: Hand-sewn rolled-edge strap crafted from a single piece of alligator leather (125 x 70 mm, with a 20 mm buckle) paired with a matching gold pin buckle
- Price: Price on application
- Limited Edition (all case types): 20 movements