Chronometry: new precision solutions

By David Chokron

Precision has always been the key driver of progress in watchmaking. However, at one point in its history, chronometry became secondary to issues of price and image. A few watchmakers are once more placing it at the core of their concerns and legitimacy. Who are they? What are they doing? How are they doing it? Here are a few explanations.

rotonde de cartier It is three or four years now since chronometry once again became a live watchmaking issue. This is for several reasons.
The first is that research into new materials is one of the keys to loosening the Swatch Group’s grip on a few basic parts, namely escapement, balance wheel and, above all, spring. However, when an alternative is created, it must be proven that it is at least as good as that which it is replacing. And operating precision is a synthetic indicator that provides this proof.
The second is that competition between brands is fierce in the high-end market. They seek to differentiate themselves using everything that comes to hand. Of the entire array of arguments on offer, technology plays a major role, especially for the smallest, more recent or more breakthrough brands. For those brands, a chronometry-based approach is doubly legitimate. It re-establishes their link with historical watchmaking and it offers a pragmatic line of research. Useful when someone is accusing you of creating a concept that does not work, which is sometimes the case with these small timers.

Proof and tests
Finally, the comeback of the Chronometry Competition has put the subject back on the table after thirty years’ absence.
A few brands (some of them major) have agreed to meet on neutral and objective ground. This proves that the issue of precision is the (only?) one able to transcend group logics and egos. Indeed, the fact remains that, for a certain exacting clientele, a mechanical watch worth a certain price tag has to be precise.
Without that it is worthless. It was long believed that the tourbillon was a device intended to improve precision. But it is a device like any other: we get it to do what we want, which, in the present instance, is to appeal to visual aesthetics and affirm a degree of superior exclusivity. It took the 2009 Chronometry Competition to prove its relevance. And that was probably due to a handful of watches, a non-representative sample of the 50 or so brands selling a tourbillon. However, chronometry stems from multiple origins. Operating precision is the result of … absolutely everything. It is influenced by all factors of the watch, internal and external. And it occupies a special place in the minds of some manufacturers who focus on it and make a success of it. They work on the side, gradually clawing back precious seconds every week or every month. This is quality. What, therefore, are the techniques and applications of the new chronometry?

Walking the spring
Enough has been said on the subject, the tourbillon places the balance wheel and spring in a varied number of positions, getting them to rotate around each other as they beat. In doing so, it reduces the impact of gravity on the regulating organ. However, it is a highly complex movement and one that can be approached differently, even though this may reduce the number of positions the spring can adopt.
While some (Jaeger-LeCoultre, Greubel Forsey, Franck Muller) introduce more rotation axes to increase the variety of positions, others do the very opposite. In 2009, Zenith presented its Zero Gravity concept, which is tantamount to a tourbillon and has since been used in the Christopher Colombus model. The escapement is gimballed to ensure perfect horizontal positioning, the position in which regulation works best.
Cartier adopted a similar solution with its Astrorégulateur. There are just two positions for the escapement mounted onto a micro-rotor. Horizontal or just one vertical position. It then simply requires regulating accordingly. Cartier claims to be able to regulate +1 s. a day, on the wearer’s wrist and in tests.
Jacob&Co also proposed the Cyclone, a movement developed by La Fabrique du Temps, in which the escapement is mounted on the rotor. It is to be noted that all three systems make abundant use of complex differentials. Finally, Hautlence consolidated the axis of its balance wheel with a jumping hour. In the HL 2.0 model, the escapement completes a 60 degree rotation every hour, each time the jumping hour advances. All these solutions make it possible to correct the effects of gravity with an alternative technique to the tourbillon. However, while gravity is the enemy of precision, it is even more complex in many other ways .

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