One of the most surprising things we saw at Baselworld this year was from Fabergé, which is a name not historically associated with fine watchmaking. The House of Fabergé’s most famous for the Imperial Easter Eggs – elaborately crafted and spectacularly luxurious objets d’art made for the Romanov family during the last decades of Imperial Russia. Today, however, the company has been revitalized (it’s now owned by Gemfields, a mining company which purchased Fabergé in 2013) and it’s back in the jewelry business – as well as in the fine watchmaking business – in a big way.
The surprising thing we saw was the Fabergé Visionnaire Chronograph. What’s surprising about it is not that Fabergé is producing a chronograph per se, but more that it’s producing this particular chronograph. The Visionnaire Chronograph, as we reported earlier this year, was designed by Jean-Marc Wiederrecht, and manufactured at Agenhor, his complications specialist workshop. The AgenGraphe caliber AGH-6361 is not just a custom chronograph caliber, but also one that incorporates a plethora of technical innovations, and whose architecture allows the unusual central chronograph configuration of the Visionnaire Chronograph.
I pride myself on being able to recognize the major components of a chronograph, but the AgenGraphe caliber AGH-6361 is the first chronograph movement I’ve looked at in many, many years, where my first reaction was, "I have no idea what’s going on here." I don’t feel terribly guilty about it, though; the architecture of the movement, as well as how it works, are dramatically different (to the extent that anything in the fundamentally incremental art of watchmaking is dramatic) from any other chronograph.
We covered some of the movement’s unusual design features in our introductory coverage, and now we’re going to go into a bit more detail. Most chronograph movements have the chronograph works built on top of a standard watch going train. The traditional method is to put a driving wheel on the same axis as the fourth wheel of the going train, which turns once a minute and is thus a natural power source for an elapsed-time train (which is basically what a chronograph gear train is).
The A. Lange & Söhne Datograph (above) is a classic example of a lateral clutch system. The gold wheel in the center is the main chronograph wheel which carries the center chronograph seconds hand, and right next to it, to the right at 3:00, are (from left to right) the intermediate wheel and driving wheels. In the picture above, the chronograph is running. You can see the very fine, pyramidal teeth on the chronograph seconds wheel and intermediate wheel – when the clutch is engaged, it’s possible for the tips of the teeth to clash, and this can create a minute jump of the chronograph center seconds hand on start-up. You can minimize this by making the teeth as fine as possible but it’s impossible, in the classic system, to eliminate completely. A vertical friction clutch doesn’t have this problem, but as it uses friction rather than gearing for engagement, it’s possible for slippage to occur (this in most cases, is an abstract rather than real world problem, but it can happen).
The AgenGraphe caliber, on the other hand, uses a very different kind of layout. The mainspring barrel, going train, and automatic winding system form a ring around a central space, in which the chronograph mechanism sits. Think of it as a donut, with the automatic winding system and going train forming the donut itself, and the chronograph mechanism sitting in the donut hole.
To understand caliber AGH-6361, it’s helpful to remember that unlike a conventional chronograph, all three registers (seconds, hours, and minutes) are on the same axis. This is what allows you to have a very compact layout capable of sitting in a hole in the center of the mainplate (in most other chronographs, the largest diameter of the chronograph train is basically that of the mainplate, which is why the chrono train sits on top of the main going train.
The AgenGraphe caliber AGH-6361 is the first chronograph movement I’ve looked at in many, many years, where my first reaction was, ‘I have no idea what’s going on here.’
The clutch system is one of the most unusual features of the watch (although it’s got a lot of competition; there is hardly any part of the caliber AGH-6361 that isn’t radically different from what you’d seen in an ordinary watch). Technically, this is a lateral clutch system, controlled by a column wheel, but it’s a clutch that operates by friction, which is how a vertical clutch system operates.
The first wheel on the clutch is a driving wheel, which is propelled by the going train.The second wheel is an intermediate wheel. Finally, there are three wheels, stacked on the same axis, like a triple-decker layer cake. Up top is a conventional toothed gear wheel, which is driven by the intermediate wheel. Directly below that is a wheel with no teeth. And finally, below that is a "security wheel" with very fine, relatively widely spaced teeth.
In the image above, the chronograph module is dead center, with the clutch lever to the right. (Please note also that this movement is a prototype; finish is not finalized in this example.) The driving wheel is the large, gold colored gear at 3:00, and the intermediate wheel runs in the jewel just above it; the last set of stacked wheels is right above the central chrono module, at just about 12:00. When the chronograph is activated, the clutch lever pivots on the axis of the gold driving wheel, and the set of stacked wheels drops into contact with the large grey wheel, center. You’ll notice that this wheel has no teeth. The center wheel in the triple stack has no teeth either – both have a slightly roughened outer edge, and the friction between the two – maintained by the pressure of the "tulip" spring assembly at the top of the picture – keeps them engaged.
The lowest gear in the triple stack isn’t visible in the live movement shot but you can see it in the diagram above – this is the "safety wheel." This wheel has very thin teeth, and it has a mate, under the toothless central chronograph wheel. When the chronograph is engaged and running, the teeth of these two gears are not engaged. However, if there’s a shock, and the toothless gears disengage, the safety wheel keeps the clutch mechanically coupled to the chronograph. The size of the gap between the teeth in the safety wheel has been calculated so that no more than a 0.33 second error, maximum, can be created by a shock.
The chronograph assembly uses a stack of snail cams in order to advance the central chronograph hour and minute hands. The first cam is on the pivot of the seconds hand. At the 60th second, a beaked lever riding on the outside of the cam drops onto its lowest point; this indexes a wheel on the pivot of the minute hand one tooth forward, counting off one minute. A second cam on the minute hand pivot does the same to advance the hour hand. The minute and hour hands jump instantly.
The same cam system allows the caliber AGH-6361 to omit the hammer and heart-piece system used in conventional chronographs. When you stop the chrono to read off the elapsed time, a brake system freezes the chronograph wheels in place. Pressing the reset button lifts the brakes out of position, and the pressure of the beaked levers on the cams (under the pressure of spiral springs on their pivots) causes the cams to rotate until the lever rests on the lowest point of the cam, which corresponds to the zero position.
There are several technical advantages to the system – because the clutch is a friction type, there is no jump of the chronograph seconds hand at start-up (which is a characteristic of the classic lateral clutch system) and the safety wheels ensure constant engagement of the driving wheels with the central chronograph wheel. The forces in the reset system of the AGH-6361 caliber are lower than those in a tradition hammer and heart-piece system as well, which reduces mechanical stress.
From a practical standpoint, this allows you to have the hands all on one pivot, which lets you read off elapsed hours, minutes, and seconds in a more natural way; legibility is improved over the usual system of sub-dials as well. The trade-off is greater complexity and a need for very exact adjustment of tolerances. The chronograph pusher feel is noticeably different; during start, stop, and re-set, the Visionnaire chronograph’s pushers move very smoothly and crisply, but it takes noticeably less force to push through the detents and activate each operation.
The whole system is really a hybrid – a combination of a vertical friction clutch and a lateral, toothed-gear clutch; the intention seems to have been to obtain the advantages of both, with the disadvantages of neither. Basically, it’s a lateral friction clutch system, with a reset-to-zero system that also functions as the coupling system for the minute and hour registers. The design is extremely ingenious, to put it mildly. It also seems to require exceedingly exact manufacturing tolerances, and it doesn’t give the impression of being very forgiving in terms of adjustment – there are a lot of springs working against each other that have to do their job without producing excess drag in the system, but in practice and here in our office, it worked very well.
This is a self-winding chronograph, and yet, you can’t see any rotor through the caseback. That’s because it’s actually on the dial side of the movement. Now, normally it would be impossible to place a rotor on the dial side of a chronograph, because the pivots for the chronograph registers are in the way, but it’s possible with caliber AGH-6361 because all the hands are on the same central axis.
Is all this ingenuity and inventiveness really necessary, though? That, as they say, depends. To a certain degree, you could look at this whole thing with a jaundiced eye and judge it as a bunch of very clever solutions looking for a problem. Modern vertical clutch chronographs from the likes of Rolex and Omega aren’t really known for chronic issues with slipping plates; lateral clutch chronographs from the Speedmaster to the Datograph, and on and on, seem to fill their respective functional bills just fine, an occasional minute stutter on startup notwithstanding.
However, there’s also no doubt that though a huge amount of clever watchmaking has been expended on coming up with solutions to somewhat minor problems, it’s also true that they are actual solutions, and that a number of the problems addressed have been longstanding ones in chronograph functionality and reliability. It’s also true that the design of the Fabergé Visionnaire would have been impossible without the caliber AGH-6361. (The movement for now is only being used in the Visionnaire, but will be used in at least one other watch from another manufacture later this year). If you’re looking for something with very unusual aesthetics and some of the most forward-thinking horological engineering out there right now, interestingly enough, you should be looking at a complicated timepiece from the House of Fabergé.
The Fabergé Visionnaire Chronograph: as shown, in rose gold and titanium, $39,500 (also available in a black ceramic and titanium model, $34,500). Movement, caliber AGH-6361, self-winding central chronograph with five hands on a single pivot. Bearingless rotor carried on a film of oil between two metal plates; platinum weight; 477 components, running in 67 jewels at 21,600 vph. Dimensions, 7.18mm x 34.40mm. Adjusted to six positions. Case, 43mm in diameter, and 14.70mm thick; water resistant to 50 meters, with a power reserve of 60 hours. View Fabergé’s watch collections online right here.