Exclusive: Romain Gauthier Logical One Constant Force Timepiece

Romain Gauthier Logical One

It has been quite some time since we have seen a new model from high-end independent watchmaker Romain Gauthier, and with good reason, he has been hard at work developing his new masterpiece, the Logical One. Breathtakingly beautiful, this highly complicated timepiece tackles one of the age-old challenges of mechanical watchmaking; constant force.

Constant Force
For those not familiar with the concept – at least in the context of watchmaking – it’s worth spending a couple of lines discussing it, otherwise most of this article will probably not mean much to you. The premise of constant force is quite straight-forward; essentially the idea is that the output remains constant regardless of the level of input. For example, your 7-series doesn’t suddenly start running more slowly because you have less fuel in the tank. It’s probably not something you even think about on a regular basis as the concept is so intuitive it is almost just taken as a given. Except in mechanical watchmaking.

As many of you would know already from anecdotal experience, the power supply that runs and regulates the vast majority of high precision mechanical timepieces varies greatly according to the state of wind of the mainspring. Although accepted largely as the norm this concept has always baffled Gauthier;

‘Coming from an engineering background, it appeared strange to have a high precision machine forced to run at varying power levels. So I started with the premise that it would be better to have constant energy.

Romain Gauthier Logical One

Sounds simple enough, but really it’s not, which is why constant force timepieces are so highly prized.

The Logical One
For his own interpretation of how a constant force system should work, Gauthier took one of the oldest and most traditional methods of supplying constant force to a watch/clock movement – the chain-and-fusee – and re-engineered the entire process to overcome the weaknesses inherent in the original design.

By the way of background, a fusee (‘fusée’ is French for cone) is a cone-shaped pulley wound with a cord or chain that attaches to the mainspring barrel and compensates for the diminishing torque/power of the mainspring as it runs down. It has been in use in watchmaking since about the 15th century and as modern technology has continued to improve – allowing for the manufacturing of ever smaller chains – it has always presented two main challenges.

Firstly, the stacked, conical shaped construction of the pulley requires multiple layers of chain (often eight turns on the fusee) and so this means that the individual links have to be incredibly small to accommodate this, instantly making them weaker. Secondly, again due to the cone-shaped design, the chain is often transmitting force between the fusee and mainspring barrel at an angle, which is both inefficient and adds stress.

Romain Gauthier Logical One

To overcome both of these shortfalls Gauthier has come up with an ingeniously simple solution. He has replaced the traditional conical fusee with a slowly rotating snail cam, which is situated at 10 o’clock to the left of the hour/minutes dial. This clever design not only puts the fusee at the same level as the mainspring barrel, ensuring force is always transmitted in a straight-line, it also means less chain is required overall and so the links can be significantly bigger and stronger.

Now, like any good engineer, Gauthier took a step back, surveyed the improvements he had made to the existing system, and then found ways that further improvements could be made as a result of the originals. To wit, he has taken full advantage of the larger chain links by making the links in low-friction hard-wearing synthetic rubies. The physical benefits of this are obvious, but the consequent visual affect is also quite stunning.

Similarly he has done away with the traditional crown-winding system, replacing it instead with an innovative push button winding system, with the pusher set neatly into the left caseband. This system transmits force to the barrel on the same plane, as opposed to the 90° between a traditional crown and mainspring barrel, making it more reliable over time.

As if that wasn’t enough he has also placed the mainspring barrel between two sapphire plates to eliminate any sources of friction that may develop over time as the spring winds and unwinds within its housing. In traditional movements the main spring is contained within a brass barrel, and as the spring unwinds it scratches the metal housing, even when freshly greased. This can lead to issues over time as the barrel can stick to the spring and does not rotate smoothly.

Romain Gauthier Logical One

It Has To Look Good Too
Now as we all know, function is nothing without form. It doesn’t matter how complex a timepiece is, if it doesn’t look good too than it is simply not a winner in my book. Fortunately Gauthier more than has us covered in that department.

The movement for Logical One was entirely conceived, developed, designed, produced, decorated, assembled and regulated by Manufacture Romain Gauthier. The design is relatively simplistic from an aesthetic point of view, with a strong focus on symmetry and balance. It is characterized by hand-finished, highly polished sharp internal bevelled angles in the movement plates and bridges and double-angle bevels with sharp internal angles, which effectively ‘frame’ the movement.

Presented in a 43mm red gold or platinum case, official pricing and availability have not yet been confirmed, but expect the former to be a rather large number and the latter to be rather small.

The Final Word
Although Gauthier may be lesser known than some of his independent watchmaking contemporaries, he is no less accomplished, and the Logical One certainly proves that. This is traditional watchmaking at its best, find a problem and then find an innovative way to solve it without compromising on quality or aesthetics. Perhaps created with collectors and aficionados in mind, this is nonetheless a timepiece that can be appreciated by all.

We will be getting hands on with this incredible timepiece very soon, so stay tuned for a hands-on review in the next few days!


Tom Mulraney
Tom is the founder and editor of The Watch Lounge. Together with his team he is dedicated to bringing you the best, original content you won't find anywhere else on the net.

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