The Moser Pioneer Cylindrical Tourbillon Skeleton (3811-1200)

Moser has a well-earned reputation for doing things its own way, and although the days of making watches decorated with living plants, or that skewer the design language of electronic watches made by a little company in Cupertino, seem to be behind it, what it’s left with is a range of watches that don’t look like anything you can get from anyone else, and which moreover have a pleasingly coherent design language themselves. The company’s product families – Heritage, Pioneer, Endeavour, and Streamliner – all feature strong, clear visuals, daring use of color, and careful deployment of, usually, minimalist details that have made Moser a standout presence in the world of independent watchmaking.

Such a design philosophy might seem a bit at odds with the basic idea of complicated watchmaking, but in fact, Moser has developed a number of interesting variations on classic complications, including the Streamliner Chronograph, which uses the cutting edge Agengraphe caliber, and more exotic and unusual complications as well, including the Endeavour Chinese Calendar. Moser has also created a number of different variations on the tourbillon, one of the most unusual of which is their cylindrical tourbillon, which uses a cylindrical balance spring. We’ve seen this tourbillon in a collaboration with MB&F, and Moser has also produced it in the Pioneer Collection – the Pioneer Cylindrical Tourbillon Skeleton (3811-1200), which we’re looking at this week for A Watch A Week.

The Moser Pioneer Cylindrical Tourbillon Skeleton originally came out at Watches & Wonders 2022, was the second implementation of the cylindrical balance spring following the MB&F collab, which launched in 2020. The cylindrical balance spring is, as they say, just what it says on the tin – a balance spring in the shape of a cylinder, rather than the flat spiral shape of the vast majority of other balance springs. Spherical, hemispherical, and cylindrical balance springs are extremely rare in modern watchmaking for two reasons – the first is that they’re difficult to make, and they’re generally produced in such low volumes that they don’t benefit from economies of scale, so they’re more expensive to boot. (One of the few companies that occasionally produces watches with such unusual balance springs is Jaeger-LeCoultre, whose Watches & Wonders debut, the Duomètre Heliotourbillon Perpetual, also uses a cylindrical balance spring).

As you can see, the cylindrical balance spring is pinned, at the bottom, to the balance staff (the bottom-most coil spirals inward) and to the stud at the top, where the last turn of the spring is shaped like a Breguet overcoil. The cylindrical balance spring as a matter of fact, was invented to offer some of the same benefits of a Breguet overcoil – the first such spring was made by the English watch and clockmaker John Arnold and they were a standard feature for many decades, of marine chronometers.

Most technical innovations in watchmaking were developed to solve a specific problem and so it is with the cylindrical balance spring. A flat balance spring has one major disadvantage. As it expands and contracts, it tends to do so asymmetrically, and the result is that the balance pivots are pushed against the sides of their jewel bearings every time the balance oscillates. This puts an uneven frictional load on the balance pivots as the balance oscillates back and forth and contributes to undesirable variations in rate. To address this, Breguet developed the overcoil balance spring, in which the outermost coil of the spring is raised above the level of the other coils, and then turned inward. This partly solves the problem, but Arnold intended the cylindrical balance spring to address the issue more completely.

John Arnold was of course, a close friend of Breguet’s and in combining the cylindrical balance spring with the tourbillon, you have two inventions which, you could say, symbolize the friendship between two of history’s most important watchmakers (the connection is closer than you might think as there is reason to think that, while Breguet was granted a patent for the tourbillon in 1801, he and Arnold may have cooked up the original idea together).

The cylindrical balance spring was developed in-house, at Precision Engineering AG, a Moser subsidiary and was originally announced in 2018. In 2022, Moser CEO Edouard Meylan discussed some of the challenges involved in producing it with Logan Baker, now at Phillips and then at HODINKEE:

“We looked at ways to redevelop hairsprings that were invented 200 or more years ago, but nobody knew how to do them anymore … There was no tooling anymore. It’s very expensive. It doesn’t make industrial sense, but that’s what we like at Precision Engineering: to try to find solutions for a better isochronism, but also solutions that bring a little aesthetic twist to the watches. So we redeveloped the cylindrical hairspring.”

The movement, Moser caliber HMC 811, has been openworked for this version of the cylindrical tourbillon and the openworking is very finely done. Generally, an openworked watch is judged by several basic criteria, one of which is transparency – the big challenge when skeletonizing a movement, is removing enough material to give the movement an appealing lightness, but at the same time sacrificing as little as possible in terms of rigidity (an important factor in high precision watches – marine chronometers, for instance, typically had very massive movement plates and bridges). This usually makes legibility a secondary consideration but not in this case – the Pioneer Cylindrical Tourbillon Skeleton shows the time in a subdial at 12:00, and the hands and indexes are done in Globolight, a Super-LumiNova-based luminous material which can be made in a wide range of shapes and colors.

The tourbillon for all that it has exploded (relatively speaking) in variety and in production over the last quarter century, still retains its fascination for watchmakers, and for enthusiasts. There is no other complication that offers its unique combination of kinetic appeal, history, and technical interest. It has of course become a much greater challenge to do something really original with Breguet’s invention (or Breguet and Arnold’s, as the case may be) and in the Pioneer Cylindrical Tourbillon Skeleton, Moser has given us one of modern watchmaking’s most aesthetically successful and technically deep versions of the tourbillon.

See It Here