Constant Force, Silicon and Co.

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Constant Force, Silicon and Co. - Escapement Technology
3 minutes read
Girard-Perregaux and other haute horlogerie brands search for accuracy and precision in the escapement.

In the making for six years already, Girard-Perregaux officially presented its Constant Escapement last week in Zurich. Its name is a double entendre of sorts: it honors both founder Constant Girard and the fact that it is a true constant force escapement. Two things have kept talk of this escapement healthy since it was first shown at the SIHH in 2008: it is breathtakingly different from any other escapement, ever. And it was conceived to accommodate high frequency.

 

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The look of the Girard-Perregaux Constant Escapement places emphasis on the technical aspects © Elizabeth Doerr

 

The finalized form of this escapement is no longer set for high frequency, even though it has been successfully tested at speeds up to 7 Hz. In fact, it is now set to 21,600 vph (3 Hz) so that it is just slow enough to see in action. And this is not something any true aficionado of high watchmaking would want to miss: the view of the two escape wheels performing their ballet along with the buckling of the blade keeps the eye mesmerized. The silicon blade, with its blue color achieved by thermal treatment in the clean room of partner institution CSEM, is only 14 microns thick, six times thinner than a human hair.

 

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This is the first Girard-Perregaux caliber to contain the constant force escapement called Constant Escapement © Elizabeth Doerr

 

Rather than high speed, precision and regularity are the declared goals of this new escapement, which also features various parts made with LIGA nickel-phosphorus. While at the moment, thanks to ten prototypes currently in rigorous testing, it displays a precision more or less equal to that of the standard Swiss lever escapement, it does have one advantage over that ubiquitous horological element: it displays true constant force (meaning little fluctuation in energy provision or amplitude) over the course of its seven-day power reserve, which is possible due to the use of twin double spring barrels, each of which boasts 1.5 meters of mainspring. Yes, that totals three meters of mainspring in this watch.

Other brands established in the experimentation with unique escapements include Breguet and Chopard. Breguet, in fact, came out with its 10 Hz escapement in 2011. This incredible speed was also only possible due to use of silicon as Breguet CEO Marc A. Hayek explained to me last year. Some cryptic comments he made lead me to believe that high frequency in and of itself is not the final goal for his company. This is just a stepping stone to another, not-yet-revealed use within Breguet's movements, which are now all outfitted with silicon escapements. This year at Baselworld, we will see the 10 Hz chronograph come out in a very aesthetic rose gold case.

 

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The Chopard L.U.C. 8HF, presented at Baselworld 2012 © Elizabeth Doerr

 

Chopard, too, has done much research in this area and after a few experimental showings finally released the limited edition 8 HF last year at Baselworld. With HF standing for “high frequency,” it is not hard to imagine that this timepiece ticks at 8 Hz. Its escapement is fully crafted in silicon, and its purpose is higher precision.

 

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The back of the Chopard L.U.C. 8HF allows a view of the silicon escapement © Elizabeth Doerr

 

As British master watchmaker George Daniels explains in his book “Watchmaking,” timepieces containing this component not only run smoother, but are popular among collectors thanks to their rarity. “The use of the remontoir is by far the best method of smoothing the power supply, but it is complex and costly to make. For this reason, watches with remontoirs are very rare, and this, combined with their attractive action gives them a special place in the affections of the connoisseur of mechanics.”

Girard-Perregaux, whose Constant Escapement does not use a remontoir, but boasts true constant force, may now have found a place for itself within those same expressed affections. Time will tell. “This is the first,” exclaimed Girard-Perregaux CEO Michele Sofisti at the presentation in Zurich on March 25. “There is more to come!”

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