In this multi-part series, International Watch explores the variety of escapements available within a wide range of timepieces. As you’ll see, the Swiss lever escapement has come a long way since it was first devised in the late 18th century.
In 1754 an Englishman by the name of Thomas Mudge invented the lever escapement, which would rule watchmaking for centuries. The lever did not, however, make its way into a timepiece until 1769 when Mudge used it in a watch he produced for Queen Charlotte of Great Britain. Since then, the lever escapement has reigned supreme. It remains the primary main escapement used by most of the watchmaking industry today.
Over the last few decades however, and for various reasons, we have seen a bigger push from the watch industry to produce in-house escapements, steering away from the traditional lever.
This endeavor has been carried out by the smallest of independents as well as the giant luxury conglomerates that dominate watch production. We see a range of new escapements being released on an ongoing basis, from minor upgrades of the lever to downright mind-blowing fresh concepts.
This four-part series will cover a range of those escapements. In these articles, we’ll briefly outline how the watchmaking industry today continues to tweak or replace traditional escapements as it seeks to create the ultimate timekeeper.
In this article we’ll discuss how Nomos, Rolex and Breguet are developing their own escapements.
Nomos Swing System
The Nomos Swing System is perhaps the least revolutionary of the new escapements, as the term ‘swing system’ is not a type of escapement but is instead the Nomos terminology for its in-house escapement. Put simply, the Nomos Swing System is a lever escapement. What sets it apart though is the manufacturing process. Nomos produces it in-house to complement its in-house movement production.
The Swing System gives Nomos more autonomy, allowing the brand to do away with traditional suppliers of escapements.
Is Nomos reinventing the wheel? No, but nor is it pretending to. Nomos is manufacturing its own quality version of a centuries-old invention that worked in 1754 and works today, and Nomo is doing it well. With the Swing System, Nomos can control production, cost and quality, which ultimately means a better product for the end consumer.
The Rolex Chronergy escapement is one of the many features unveiled in Rolex’s new 32xx family of movements. The Chronergy is an adapted version of the lever escapement Rolex has designed to be more efficient and increase accuracy.
The first area Rolex addressed was the weight. Rolex has opted for a pierced style of escape wheel, meaning excess material from the inside of the teeth and body of the wheel has been removed, which will reduce inertia and allow more efficiency.
The second area Rolex tackled was geometry. The lever escapement has a very specific layout, but Rolex decided to change that layout and structure when developing the Chronergy. Rolex has halved the thickness of the pallet stones and doubled the contact surfaces of the escape wheel teeth, which makes for an interesting looking escapement indeed. The effect this has on actual performance is not immediately quantifiable (Rolex claims 15 percent greater efficiency), but it is true that by decreasing the stone thickness you’ll also reduce oil drag.
The Chronergy is offset, which means the pallet fork is no longer manufactured at a traditional 90-degree angle. Without studying the in-depth mathematical aspects we cannot know exactly how this performance increase is achieved, but a company like Rolex doesn’t do things for without a strong technical reason, which leads me to believe this technique is more efficient.
Having personally trained on the new Chronergy escapement I can say that it is a beautiful piece of horological engineering and a step forward for Rolex.
Breguet Magnetic Pivot
Like oil and water, a watch escapement and magnetism do not mix. The majority of watch houses these days are striving to make their watches more anti-magnetic than ever before to improve timekeeping and accuracy.
However, Breguet decided to take a different route. By adding two magnets into an escapement and making it an integral part of the structure, Breguet’s watchmakers have managed to achieve the exact opposite of magnetic interference, resulting in greater accuracy and improved timekeeping.
To ensure the watch stays antimagnetic, the entire escapement is constructed from silicon - escape wheel, balance springs (the watch has two) and pallet fork. This ensures magnetic interference does not affect the escapement functions.
The escapement features two magnets, both hovering above the pivots of the balance staff located on top of the endstone jewels. In essence, these magnets take the place of a traditional brass spring that would in traditional escapements absorb impact.
The magnet, which sits above the dial side pivot, is stronger than the magnet located on the movement side pivot, which forces the balance towards the dial, in turn allowing the bottom pivot to appear suspended. This means that the tip of that movement side pivot is not in contact with the endstone.
The purposes of the magnets are twofold: to allow the balance to return quicker to regular oscillations after a shock and to reduce friction in various positions.
If the watch receives a small blow, the magnets are powerful enough to keep the balance in its position, which allows the escapement to continue functioning without interruption. If a larger blow is received, the balance will return to its original position faster due to the magnetic pull.
This is an interesting concept put forth by Breguet but whether this has actual increased performance in a real-world scenario is something to be looked into further.
Where this escapement shines in my opinion is the vertical positions. Many watches spend their life in these positions simply due to the fact that this is how your arm naturally hangs. The friction placed on the balance pivots at this point is greatest, as the length of the pivot, no longer just the tip, is in contact with a jewel. Simply put - more surface contact (more friction) decreases performance.
With the magnets in play, the stones no longer rest on their length but stay suspended by the magnetic field, which will decrease friction and increase accuracy and performance.
The Breguet magnetic pivot is certainly an interesting design and I think Breguet sums it up nicely: “It is likely that the impact of this important invention will not be fully assessed for some years yet.”
WOSTEP-trained watchmaker Ashton Tracy operates Ashton Tracy Independent Watch Repair in Ottawa, Canada.