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Roberta Naas on Constant Force

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Roberta Naas on Constant Force 52 INFLUENCE elite WATCHES traveler MAY/JUNE 2018 Roberta Naas on constant force Just 20 pieces will be made. Watchmakers are an elite group of Another way to achieve constant force perfectionists who toil every day to create is via a remontoire system (from the French word remonter, or ‘to wind’), the most precise timepieces possible. That which consists of a second spring (or quest has led to the unveiling of mechanical power source) strategically placed between the escapement and the barrel watches that feature what may be the to absorb the mainspring’s energy and ultimate precision concept: constant force release the power to the escapement balance at specific intervals of time. Grönefeld, a Netherlands-based independent watch brand, has mastered this system in its Grönefeld 1941 watch will run for the duration of its Remontoire collection. The watch is power reserve, then stop. Generally, in equipped with a remontoire with a com its fully wound state, it delivers stronger release system that is activated every torque in the first few hours of running eight seconds (10,800 times a day). It time before leveling out. Then, toward IWC winds the second small hairspring and the end of the watch’s power reserve, the ensures that the force serving the torque slows until it stops. This balance does not wane, but rather offers inconsistency of the mainspring’s a smooth and consistent power transfer. unwinding power renders the watch The newest Grönefeld 1941 Remontoire slightly inaccurate. Granted, we are watches are crafted in stainless steel and talking minor inaccuracies, but in haute feature bespoke dials engine-turned by horology, precision is king. As such, watchmaker Kari Voutilainen. certain brands search for ways to A handful of other brands achieve improve the isochronism of awatch. constant force by changing the elements Today, constant force is achieved in in the escapement itself. Often referred several ways. One way is to utilize a to as an elastic constant escapement, this complex fusée-and-chain system. These solution is relatively recent and is systems date back to the 17th century in possible because of the development of While constant force is not a new large-format clocks, but today top brands silicon components. Essentially, the concept in watchmaking, the idea of have perfected and miniaturized them to elastic silicon escapement stores the delivering consistent power to the such a degree that they can fit a chain energy in units, delivering constant watch from the moment it is fully (usually with more than 600 parts) and impulses to the oscillator. wound all the way through to being fusée (pulley) inside the watch. The In its new hand-wound Portugieser completely out of power has taken system works similarly to the gears of a Ferdinand Berthoud Constant-Force Tourbillon Edition 150 center stage with many bicycle. It uses a cone-shaped pulley Years watch, IWC Schaffhausen uses a watchmakers. Though errors of a linked to a chain that is coiled around the patented constant-force mechanism fraction of a second each day may not barrel. As the mainspring unwinds, the integrated into the tourbillon disturb the wearer, they certainly disturb chain rolls on the barrel and off the escapement to transport even impulses top watchmakers who strive to achieve fusée, with its leverage compensating for to the escape wheel. A highlight of the perfection in mechanical watches. waning torque. brand’s Jubilee collection, the limited- Centuries ago, watchmakers utilized the Independent Swiss brand Ferdinand edition platinum watch houses the pendulum and other systems to deliver Berthoud employs a fusée-and-chain IWC-manufactured hand-wound 94805 somewhat constant power. As system in the Chronomètre FB-1R.6-1 caliber with a power reserve of 96 hours, mechanical watchmaking has evolved, tourbillon watch. The barrel of the constant-force tourbillon and new technologies and systems were movement features a Maltese cross moonphase display that needs to be developed that helped to improve stop-work device that limits the winding adjusted by one day every 577.5 years. accuracy immensely. Still, one of the turns of the mainspring to prevent There are many watch pundits who biggest issues in a mechanical watch overwinding. The fusée-and-chain claim that the quest for constant force is Chronomètre FB-1R.6-1, $241,500, available at Les Ambassadeurs in Geneva, +41 223 186 222, ferdinandberthoud.ch stems from minor inaccuracies in timing transmission and the tourbillon unnecessary given the accuracy of due to inconsistent delivery of power escapement of the Caliber FB-T.FC.R can today’s mechanical watches. However, from the mainspring barrel (where the be seen through a sapphire caseback. certain top watchmakers disagree, and 1941 Remontoire, from $64,000 in stainless steel with engine-turned dial, available at Manfredi Jewels in Greenwich, CT, +1 203 622 1414, gronefeld. energy is stored) to the regulator of a The newest version of this watch is given the fact that these expensive pieces Portugieser Constant-Force Tourbillon Edition 150 Years, $249,000, available at IWC in New York, contact Dawn Simonson, +1 212 355 7271, iwc.com watch (which controls timekeeping). rendered in a 44mm stainless-steel case sell, it would seem certain watch When fully wound, a mechanical with a regulator dial in black rhodium. Grönefeld collectors agree. 1. IWC 2. Ferdinand Berthoud 3. Grönefeld.
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