The Tourbillon Controversy: Does a Tourbillon Serve Any Purpose in a Wristwatch?
Ian Skellern 11/23/16
This article was originally published in the Numero 1, Fall 2016 edition of the F.P. Journ[al]. We’d like to thank our friends at F. P. Journe and author Ian Skeller for allowing us to reprint it. Look for more articles from the F. P. Journ[al] in future posts.
Observing that the regular functioning of a pocket watch was influenced to a large extent by the watch’s position, Breguet concluded that the cause of such variations was due to the effects of gravity on the escapement.
Apparently, it did not occur to him at that time (though it did after) that perhaps these variations were also due to the other components in his watch’s movement. Breguet constructed watch components to such a high standard that he considered the perfect craftsmanship and pairing of balance wheel and balance spring to be a given. lt was eventually discovered that perhaps the more major problem affecting accuracy had to do with inconsistencies in
the balance wheel as well as friction. For a watch’s operation to be isochronal (i.e., to produce a stable rate), the balance wheel must be perfectly circular and poised and the hairspring must extend and contract symmetrically from the exact center of its coil. Breguet’s overcoil configuration of the hairspring indicates that he eventually came to realize this, but was it too late and perhaps commercially unwise to retract his belief in the tourbillon’s chronometric brilliance?
Even if the tourbillon did a good job compensating for errors caused by a watch adopting the vertical position for most of its life, compounded by poor oil quality, the modern wristwatch shares none of these characteristics. So the question has to be asked: In the era of modern wristwatches, which are (a) rarely vertical, (b) lubricated with quality synthetic oils, and (c) if well designed, constructed, and regulated, show minimal rate deviation through positions, is there any technical justification for a wristwatch tourbillon? At the heart of the matter is the controversy about whether wristwatch tourbillons are actually chronometric or if they are simply expensive and complicated energy-wasting devices. We asked the experts, but their opinions seem divided.
“From an accuracy perspective, placing a tourbillon in a wristwatch makes it a worse timekeeper. You have to have a smaller balance; the tourbillon cage is affected by forces every time you move your arm and very few tourbillons on the market today are well regulated. Adding a tourbillon to a precision timepiece is like deliberately breaking your ankle before a 100-meter sprint. Adding a remontoir d’egalite is like wearing a splint; it helps, but you would have been better off without the break in the first place”—François-Paul Journe.
“Yes, a tourbillon has a positive chronometric effect but only when the balance is of a substantial inertia. In general terms, only a balance wheel that is greater than 10mm in diameter and that beats at a rate of 21,600 vibrations per hour or higher will have a positive effect on accuracy. Conversely a balance wheel of a smaller diameter will have a negative effect on accuracy”—Giulio Papi, technical director and founder, Audemars Piguet Renaud & Papi.
“For the cage to not influence the amplitude of a watch too considerably, it must have minimum weight. To make it light, it must be made as thin and delicate as possible. This requires a great deal of know-how to build. But even if the cage is extremely light, it still takes a lot of energy. So, as a result, the balance has to be made relatively small. If a balance is too small, you don’t have a stable watch”—Jean Pierre Musy, technical director, Patek Phillipe.
Although it appears that the size of the balance wheel is a factor, this doesn’t address the more glaring issue related to the position of the balance. The general vertical nature of the pocket watch in Breguet’s day was a key factor in the tourbillon’s invention because the tourbillon only has a (positive) effect when the rotation of the cage or escapement is in the same plane as the force of gravity. A tourbillon has no beneficial effect when the escapement is perpendicular to the gravitational force, such as when the watch is horizontal with its dial up or dial down. Unfortunately, this seems to be the position in which the modern wristwatch spends most of its time. Indeed, when the escapement is perpendicular to gravity (dial up or dial down), the tourbillon is not only not contributing toward averaging out positional errors, its very existence increases friction, wastes energy, and obliges a smaller balance wheel. In fact, it can be perceived as Jean-Claude Nicolet stated in his controversial article for Europa Star, as a parasitical organism.
“The principle of the tourbillon has been developed for pocket watches and its benefits are less powerful—almost nonexistent—in a wristwatch”—Philippe Dufour.
“The flat single axis Abraham-Louis Breguet-style tourbillon makes more sense in a pocket watch than for the wristwatch”—Stephen Forsey.
Although averaging out positional errors (in one plane with single axis tourbillon) is great in theory, the reality is that the increased friction introduced by the additional parts of the carriage usually far outweighs any gains … unless of course they are crafted with truly enormous skill by the likes of, for example, Patek Philippe or Audemars
Piguet. But the tourbillon has enormous visual appeal, which is why most are placed on the dial side of the watch. There is something unerringly romantic about the tourbillon—perhaps its reflected glow of past excellence that shines so brightly in the collector’s eyes today.
“It has to be said however that there are some real pieces of art on the market today that feature a tourbillon—thanks to their superb construction, design, and finishing”—Philippe Dufour.
“Perhaps the tourbillon draws attention because it is a highly visible complication that is much more accessible rather than the minute repeater, which has to be activated. The direct association with precision timekeeping is also a plus for the tourbillon. A fine hand-finished tourbillon remains a testament to the fine art of watchmaking”—Stephen Forsey.
“Why make a tourbillon on wristwatch? Because they look good and, done well, are a testament to the skill of the watchmaker. In my opinion, every watchmaker who has made a tourbillon after Breguet, including myself, has done so because they look good and/or to demonstrate skill—not to make a better timekeeper”—François-Paul Journe.
Many, if not most, of today’s tourbillons are certainly expensive, but using modern manufacturing techniques and high-precision CNC machines allows less experienced (compared to the past) watchmakers to craft and assemble them. Assembled and working, yes, but generally, not well regulated.
Tourbillons rule for the moment because they have a strong association with technical and watchmaking excellence; they pirouette and captivate the eye; however, the sheer number of tourbillons on the market today, many by second tier brands you would not normally associate with haute horlogerie, plus the fact that the Chinese are selling ever-better quality tourbillons from $1,000 a pop, means that sometime in the future, educated consumers may realize that most of these emperors have no clothes. People who simply are looking for a pretty whirlwind to ogle at should find them available at much more reasonable prices than those masquerading as handcrafted haute horlogerie, whereas people who are searching for true horological art will find that. Although perhaps chronometrically challenged, the tourbillon will always demonstrate skilled horological art and craft.
Ian Skellern is co-founder of QuillAndPad.com, photographer and a journalist.