Clearly, TAG Heuer has the knack of turning up right where no one is expecting it. Particularly in its 150th year, when the urge to think outside the box is stronger than ever. And deliver it did at this year’s Baselworld, where it presented its Pendulum Concept, a reference to the pendulum clock which Christiaan Huygens made in 1657, a groundbreaking realisation that drew on the work of Galileo. Such references are not by chance. The TAG Heuer Pendulum Concept is the first prototype to date of a watch whose regulating organ has no balance spring, an essential part of any movement and which has major strategic implications for the industry. Put simply, TAG Heuer has decided to revisit watchmaking’s Grail.
TAG HEUER – Pendulum
Why a balance spring anyway?
When in 2004 the company replaced the traditional gears and pinions with a belt-driven transmission in its famous V4, it was hailed a genius. However, enthusiasm waned over the years as the firm battled to stabilise the movement. Not one to give up easily, TAG Heuer called on the highest levels of expertise to reach its goal, ultimately proving the grouches wrong: virtually all 150 of the V4 have now been delivered. The same stubborn determination shines through in this revolutionary new piece. Granted, there are still problems to be ironed out but the end justifies the means a thousand times over, as it opens up countless new perspectives for movements in the third millennium.
The four main principles of a mechanical watch are to store energy in the barrel, to transmit energy through a gear train, to distribute energy through the escape wheel and pallet lever, and to regulate energy via the balance and spring at a given frequency. Says Stéphane Linder, marketing manager at TAG Heuer, “The V4 provides an alternative solution to the gear train. For our 150th anniversary, we turned our attention to the next stage, the escapement, and its biggest weak spot, the balance spring, whose oscillations are vital to a watch’s precision. While major breakthroughs have been achieved in this field, in particular thanks to Elinvar, a relatively thermostable alloy invented in the 1920s, then silicon, gravity and shocks still have an undesirable effect on the balance spring. Not to mention the difficulties of industrial production. Hence our decision to do away with the balance spring and that niggling question: what to use instead?”
The problem of magnetic forces
The solution came from magnetic fields and forces that attract and repel. The energy which the balance needs to oscillate is supplied via the pallet lever and the escape wheel, thanks to two magnets on the rotor and two on the stator. “A magnetic ‘spring’ replaces the mechanical spring,” Stéphane Linder explains. Except that a good quality, well-adjusted balance spring provides linear energy, whereas magnetic pull increases exponentially. TAG Heuer worked with the Institut de Microtechnique at the École Polytechnique Fédérale in Lausanne to overcome this hurdle, and define the optimal shape of the magnets that would correct this intrinsic “defect” and provide a constant force. Success was three years down the line. The TAG Heuer Pendulum Concept beats at 43,200 vibrations/hour and works like a dream, as Stéphane Linder happily notes by regularly checking the rate of the movement, which currently equips a Grand Carrera.
“We have found the answer to problems of gravity, shocks and lubrication, not to mention easier machining and production compared with traditional balance springs. This may seem great on first impression. However, magnets are sensitive to temperature, meaning magnetic fields vary with heat and cold. We now have to resolve this problem using either magnetic powder or, probably the most complex solution, alloys which mechanically compensate differences in temperature.” But the Grail is within reach and, knowing TAG Heuer, it will only be a matter of time before it is reached… particularly as the range of vibrations made possible by magnetic fields opens the door to the wildest applications.
This unique concept shouldn’t eclipse TAG Heuer’s core business, which is to produce high volumes of quality timepieces. “We are at the cutting edge of chronograph movements with the need for substantial industrial capacity,” Stéphane Linder comments. “We had to guarantee production by choosing a quality movement. The Calibre 1887 is equipped with a re-engineered version of the oscillating pinion, patented by Edouard Heuer in 1887 and which starts the chronograph in under two-thousandths of a second, and a column wheel, the hallmark of a quality chronograph. The column wheel in our Carrera is a complication in its own right, with its 320 components.”
Thus TAG Heuer has pulled out all the stops: CHF 20 million investment, a new production centre in Cornol, highly-automated processes without yielding on quality control, and a strongly competitive retail price of CHF 3,900. This is TAG Heuer’s major launch for its anniversary year… but did it take short cuts on the way? The firm now willingly admits to buying intellectual property patents from Seiko for its TC78 movement, which it then completely reworked. “An excellent calibre that saved us three years’ development time,” says a pragmatic Stéphane Linder. Better out than in!