Reinventing the Wheel
Of all the strange and wonderful developments watchmaking has thrown up over the past few years, TAG Heuer's V4 is undoubtedly one of the most radical. The industry has seen almost everything from novel materials being used in the manufacture of hairsprings and escape wheels to the basic architecture being exploded and re-assembled, but everyone has always left untouched the basic idea of power being transmitted through toothed wheels. Everyone, that is, except TAG Heuer.
Although watchmakers have always had to be wary of the way gear wheels mesh and recognise the need to balance precision against the freedom required to stop gears locking up, better answers have been sought in the wheels themselves and, for example, the profile of the gear teeth. Even when TAG Heuer began looking for a project that would cement and support their growing reputation for more 'horologically legitimate' watches, there was no plan to rethink this fundamental of watchmaking. As Stephane Linder, product director at TAG Heuer said 'We wanted to get back our reputation for innovation'.
The process, however, was started. And as is often the way, someone with their eyes open for a solution opened a car bonnet and found one staring him in the face - the timing belts that drive the camshaft and valves of a supercar. The man in question was watchmaker Jean-Francois Ruchonnet and here was an idea that was not only revolutionary but one that was directly inspired by the core brand association that is at the centre of TAG Heuer's being - a stroke of genius that even Archimedes might have appreciated. And even better, there was no need to involve a tourbillon.
After the lightning stroke, the deluge of perspiration. Apparently the idea of using the belts to create a movement that mimicked the form of an engine came quite quickly, but the scale of the challenge emerged more slowly. It took nearly two years to put a basic design together and create a concept watch that worked well enough to prove and demonstrate the idea.
The Drawing Board
Despite involving luminaries such as Philippe Dufour and Ruchonnet, it quickly became clear that conventional watchmaking was not going to find the solution to the technical challenges the concept presented. No watchmaker has ever looked into the ways bands behave - it was a question that had simply never arisen. TAG Heuer's designers did not just have to go back to the drawing board, they had to take a fresh look at the board itself!
According to Linder, the scale of the changes TAG Heuer would need to make was not even fully realised when the concept was unveiled at Baselworld in 2004. Luckily the reception was verging on the rapturous - I distinctly remember seeing knowledgeable watchmakers looking at the prototype in both wonder and horror. I was less aware of quite how extreme an examination of movement design the V4 was, but was still shocked as much as impressed. In turn, Jean-Christophe Babin, TAG Heuer's CEO, was surprised by the enthusiasm the V4 instantly generated, the last words of his presentation were hardly off his lips before offers for the prototype were being made and orders promised. They thought it might make a splash, explained Babin, but the obvious scale of the task was considered beyond the ability and station of TAG Heuer.
Even for a brand as carefully managed as TAG Heuer, the 'if' question was answered by the reception at Basel - the question of whether the project truly met the criteria set within the company of establishing their legitimacy as a prestige watchmaker became irrelevant in the face of the enthusiasm and excitement generated by the idea. But, although doubts about 'if' may have been removed, there were still plenty of serious questions about how (and also, how much).
As normal movement development paths were being revealed as inadequate, TAG Heuer's team decided to treat the project in engineering terms. This might seem surprising in that surely watchmaking is a branch of engineering. In truth, the technology and basic principles of watchmaking are so well established that engineering movements from first principles are almost completely redundant and most developments in watchmaking are at the margins of a system already long established. As a result most movement designers are hardly trained in engineering at all.
So, the first step was to analyse what they were trying to do in engineering terms and discover the steps and processes needed. TAG Heuer defined the task into functions to be performed - broadly the transmission of energy via belts from spring barrels set in a different plane to the escapement and from the escapement to the hour, minute and second hands - and performance parameters - flexibility, stability over time and through a range of environments. These goals were then used to generate a research path designed to ensure a practicable solution for each goal and for the project as a whole. Basically the idea is to avoid developing solutions to one aspect that would have a negative effect on the whole.
The Solutions
Calculating all the variables of tension, temperature, friction, flexibility and myriad other factors meant months of work and several sessions booked on research super-computers. Having come up with a system that should work, the most difficult question the team faced was, unsurprisingly, finding a band material to fit the specification thrown up by the engineering.
Normally this is a question of turning to the appropriate references and dialling in the spec. Unfortunately for TAG Heuer no single material presented itself as meeting the requirements. And, as no one had ever sought for material specifications even remotely similar to the bands wanted for the V4, TAG Heuer's team and partners (a network of companies, universities and research institutes) had to do some hard creative thinking. The closest match was a polymer called Polyphtalamide, which although it had the right characteristics in terms of friction and resistance was not strong enough to cope with the 450g of tension generated by each pair of spring barrels. To cut a long story short, a solution was found which was to reinforce bands with a steel strip.
Naturally enough, discovering how to manufacture the bands was a significant challenge in itself and various techniques were tried, including using femto-band lasers to cut the material. In the end a high-pressure injection system was designed and again the team had to start from a blank sheet of paper as no one had attempted to try this technique on something intended to be 0.07mm wide (almost as thick as an average human hair) let alone around a steel core.
That TAG Heuer came close to abandoning the project despite the enormous investment of money and reputation already committed speaks volumes about the nature of the problems they faced. There were moments when the team thought it could simply not be done. But with the right materials and process and a working, cost-effective design (having to rely on femto lasers could have easily killed the project on cost grounds) the V4 project stayed on course.
The next step was to see if the V4 could actually be made in real life, on a real-world production line and this meant returning the project to the hands of master watchmakers. This too threw up its own challenges, mostly in terms of developing an effective production scheme, but nothing to seriously threaten the project.
The End Result
So what is it that such intense and laborious work finally created? The V4 is full of surprises both visible and hidden, but to start from the beginning: the barrel-springs are wound via a tungsten block that slides along a channel between two banks of barrels - hance the name of the watch. The block's movement drives a rack and gear system linked to one of the more intractable problems - how to transmit the energy effectively to the barrels through a thirteen degree change in plane - the watch really is a V4.
Once wound the barrel springs' energy is released via the reinforced bands to the relatively normal escapement assembly - this too required some adjustments to reflect the different energy profile of the system as a whole, one of the perhaps unsurprising benefits of the V4 being its much smoother energy curve over the period between fully wound and run down.
Apart from its striking looks and form demonstrating the will and capabilities of TAG Heuer's management, the V4 system turns out to confer a number of highly desirable benefits. Most important is that once set-up, the belt system is highly stable in the face of both immediate shocks and long term environmental attack whether that comes through temperature changes, magnetic fields or the simple passage of time. As above, the the belt system delivers energy smoothly to the escapement, there being much lower levels of energy loss due to friction and inertia.
For watch designers, the most exciting aspect is that the belts can be used to place different movement elements anywhere within the movement envelope and to see how valuable this is, just imagine the Concord's C1 Tourbillon with its three extra gear wheels needed to take the tourbillon cage to the edge of the movement. With each wheel needing utterly exact positioning the watch almost looks guaranteed not to work, but with a belt system the cage could have been placed anywhere without loss or compromise.
Perhaps the greatest surprise of the V4 is the incredible leap of faith the idea represents for a company that has few peers when it comes to careful charting of the brands evolution - it is hard to imagine the process that lead to the V4 being intended to produce anything even a tenth as radical. The success of TAG Heuer's evolution and the distance the brand has travelled was thrown into sharp relief just before I started this piece when I was shown the remains of an early 1990s quartz chrono. TAG Heuer really has come a long way.
The V4, which is now on sale, cased in platinum and in a limited edition of 150 at an astonishingly reasonable £65,000, will no doubt have lots of beautifully measurable brand benefits, but far more importantly, the V4 shows what you can make when driven by pure and genuine enthusiasm.
James Gurney, published in QP Magazine #40 (2010)
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