Modern Escapements
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 an escapement that would rule watchmaking for centuries, that escapement was known as the Lever. It did not, however, make its way into a timepiece until the year 1769, when a watch was produced by Mudge for Queen Charlotte of Great Britain. The lever escapement has reigned supreme ever since that royal watch was first commissioned and is still the main escapement used by most of the watchmaking industry today.
During the last few decades, 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 everyone from the smallest of independents to the giant luxury conglomerates who dominate the scene. 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 and see how the watchmaking industry today is moving ever forward in the quest for the ultimate timekeeper.
In this article we will discuss the big brands trying their hand at escapement manufacturing: Nomos, Rolex and Breguet.
Nomos Swing System
The Nomos Swing system is perhaps the least revolutionary of the escapements, as the term ‘swing system’ is not a type of escapement, it is merely the Nomos terminology for their in-house escapement. Put simply, the Nomos swing system is a lever escapement. What sets the swing system apart though is the manufacturing process, as Nomos produce it in-house, as they do the rest of the movement.
The swing system gives Nomos more autonomy, being able to do away with traditional escapement suppliers to the watchmaking industry, which are few and far between.
Is Nomos reinventing the wheel? No, but nor are they pretending to. They are manufacturing their own quality version of a centuries-old invention that worked in 1754 and works today, and they are doing it well. The can control production, cost and quality which ultimately means a better product for the end consumer.
Rolex Chronergy
The Rolex Chronergy escapement is one of the many features unveiled in the new 32xx family of movements. The Chronergy is an adapted version of the lever escapement and it is 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 tackled was the geometry as the lever escapement has a very specific layout. They all generally look similar. Rolex decided to change that layout and structure when developing the Chronergy.
Rolex has halved the thickness of the pallet stones and doubled the escape wheel teeth, which makes for an interesting-looking escapement indeed. The effect this has on actual performance is non quantifiable with the knowledge that Rolex has made public, but it is true that oil drag will be reduced by decreasing the stone thickness.
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 the sake of it. We can rest assured the reasons were well founded.
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
Oil and water don’t mix and the same can be said for a watch escapement and magnetism. It’s a well-known fact. The majority of watch houses these days are striving to make their watches more anti-magnetic than ever before so as 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 end-stone jewels. In essence, these magnets take the place of a traditional brass spring that in traditional escapements would 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 end stone.
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 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 = decreased 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.”