Casually Explained - The Rolex Dynapulse Escapement
5 min read
It isn’t necessarily a requisite for collector-legitimacy to have an inside-out knowledge about the workings of a watch. There are levels to understanding how a watch functions, and whether you practice a total aversion towards this mechanical backstage or define it as a primary collecting objective, there lies no harm with either. Regardless, there comes a stage in our lives when we foster an irresistible urge to draw fierce affinity towards knowing the lesser-known and then, with fervent conviction, illuminate its truths for those yet unaware. Some might dismiss it as a mid-life whim, I simply see it as passion reaching peak.
Having established the impetus as well as the incentive, the following is going to be an explanation of the Rolex Dynapulse escapement, where I promise, the word “Dynapulse” will be the most complex term you’ll encounter. I won’t relegate it as a dry technical breakdown, but more like a casual explanation of the same. And it begins with a simple understanding of the escapement.
What’s The Escapement In A Watch?
While a simple coiled spring does a good job of illustrating the concept of an escapement, it feels a bit too generic for the purpose. So, let’s consider an alternative. Imagine a large tank full of water. If you were to create an opening in it, all the water would rush out at once in an uncontrolled gush. Now, picture a different scenario. Instead of a random breach, you install a simple tap that allows only a small, measured amount of water to flow out with each opening.
In this analogy, the water stored in the tank represents the mainspring’s stored energy in a watch. The tap, opening and closing when required, acts like the escapement. It doesn't produce the energy, but it controls the rate at which the energy (the water) is released, ensuring a steady and measurable flow (the rotation of the escape wheel). A common escapement has two main components - the escape wheel and the pallet fork. The escape wheel is controlled by the pallet fork which itself is controlled by the balance and the balance spring.
Just as the tap regulates the flow of water, the escapement regulates the release of power from the mainspring, making accurate timekeeping possible. So, it’s all to do with controlled release.
What’s A Swiss Lever Escapement And What Are Its Drawbacks?
I won’t be audacious in guessing that you are already familiar with a classic pendulum clock. Even if you haven’t been in close proximity to one, it’s something you might have been taught about in high school physics. While there’s a slim chance that you still memorize the many kinetic intricacies applicable to the same, however the part known as the pendulum itself won’t be something too distant to perceive. The pendulum acts as the timekeeping element in mechanical clocks, ensuring that each swing (or tick) represents a fixed unit of time. It controls the escapement mechanism (anchor and escape wheel), which in turn drives the clock’s hands, hence creating a consistent and predictable flow of time.
Now, in a mechanical watch’s escapement, the balance acts as the pendulum and the balance spring works as the gravity force, limiting the balance’s swing. Almost every watch, usually with an exception of an Omega or Roger Smith (both use Daniels’ Co-Axial escapement) and a few others, is ideally equipped with the lever escapement. This evolution of a clock’s anchor escapement, invented by Thomas Mudge in 1755, and refined through ages to become the Swiss lever escapement, works on the borrowed principle of a mechanical clock’s escapement. Its escape wheel, driven by the mainspring through a series of gears, rotates in regulated steps, subsequently locking and unlocking the pallet fork. This motion gets regulated by the balance and the balance spring, with the resulting continual movement contributing to a consistent rate of energy release from the mainspring as well as maintaining predictable accuracy in timekeeping.
Despite the many attributes favoring a Swiss lever escapement’s reliable efficiency in timekeeping, it’s not totally immune to a few Achilles heels. Here’s where it falls short:
- The sliding friction at the escape wheel teeth and pallets requires lubrication, which eventually thickens and breaks down over time, adversely affecting accuracy.
- The impulse (driving force) delivery isn’t symmetrical with the lever arm being longer on one end than the other.
- It’s susceptible to escapement errors induced by the tiny mechanical losses arising due to friction and geometry constraints.
Despite its inherent limitations, a Swiss lever escapement is a feature in almost every mechanical watch existing on this planet. Although its execution levels as well as material preferences have been distinctly rendered across watchmaking inceptions, the underlying principles defining its form and function have remained largely the same.
Are We Clear Of The Limitations?
Agreed, friction is an enemy of mechanical efficiency, and its detriments can’t be calculated better than in a device for measurement of time units. There have been many attempts at attaining an efficient escapement mechanism by means of friction-reduction and the said has been an area of significant interest in horological innovation over decades. The efforts to yield an efficient escapement have culminated in John Arnold’s chronometer/detent escapement, Breguet’s double-wheel natural escapement, George Daniels’ Co-Axial escapement, Ulysse Nardin’s Dual Direct Escapement (direct impulse) and the Dual Ulysse Escapement (indirect impulse).
The fundamental mechanics of a Swiss lever escapement too have been optimized with altered geometry for the lever and the escape wheel, along with material innovation, in the attainment of a more efficient escapement. These include Rolex’s Chronergy escapement which introduces a modified lever geometry and a skeletonized escape wheel. The result - 15% greater efficiency than a standard Swiss lever escapement. The literal exhaust of the actual list of refinements in escapement design is a pointer of its imperativeness in yielding an efficient timekeeper.
What’s The Rolex Dynapulse Escapement?
Over the decades, Rolex has become synonymous with conservative progression and the Land-Dweller with its heft of ground-up inventiveness is quite refreshing from a brand that exercises the absolute maxima in restraint. With Rolex, the strength of its products is more dominant in the technical than in the aesthetic. They are superlative in engineering, and the same is evident in numbers with the brand’s new caliber 7135 in the Land-Dweller which features the patented Dynapulse escapement. This novel escapement itself bears seven patents.
The Rolex Dynapulse escapement is based on a double-escape wheel architecture so as to compensate for the losses of a conventional Swiss lever escapement - low efficiency, high sliding friction and need for lubrication, while retaining its positives - mass production and self-starting capacity. While it shares the double-wheel architecture of a natural escapement, the Rolex Dynapulse is different in the way that the escapement doesn’t give a direct impulse to the balance. Here, only one of the two wheels derives power from the gear train, subsequently driving the other escape wheel. Instead of a conventional lever, the escape wheels interact with an impulse rocker which gives the driving force (impulse) to the balance.
How Does The Dynapulse Escapement Work?
Let’s use a bicycle with two pedals as an example to make the Dynapulse escapement super clear. Imagine you’re riding a bike where the right pedal (driving escape wheel) pushes down first, reaching the bottom of its stroke. This locks the chain in place (like the Dynalpulse’s impulse rocker locking the wheel). Now, the left pedal (driven escape wheel) stays pre-tensioned (ready to push) with a stored bit of energy from the first pedal’s momentum and its own potential, but doesn’t move yet. The instant the right pedal lifts (unlocks), the left pedal immediately takes over with the same force without any delay or wobble, thus keeping the entire motion smooth and precise. It’s like pedaling a bike where both legs perfectly sync, so you never lose power between strokes. That’s how Dynapulse prevents lag or flutter between impulses.
What Improves With The Dynapulse Escapement?
The key to Dynapulse escapement’s efficiency lies in the interaction of its wheels. In the action of this escapement, there’s virtually no sliding friction anymore, as it’s replaced by a rolling motion, with the contact surfaces pressing, rather than sliding against each other. This almost completely eliminates the need for lubrication and thus serves the benefit of longer service intervals. By eliminating friction and losses from geometric constraints, this alternative to the traditional Swiss lever escapement betters the efficiency ratings by more than 30%.
The Dynapulse is a high-frequency escapement running at 36,000 vibrations per hour or a 5Hz frequency. It yields better accuracy in chronometry. The caliber 7140 is double certified for accuracy, first by COSC to -4/+6 seconds per day as an uncased movement, and then by Rolex in-house to -2/+2 per day as a finished watch, making it a Superlative Chronometer. It’s one of the most accurate movements offered by Rolex today.
The high efficiency caliber despite its high beat rate isn’t significantly power hungry with the movement’s mainspring offering autonomy of approximately 66 hours. The entire escapement, including the impulse rocker, the two escape wheels and the fourth wheel (intermediate wheel powering the escape wheel), is made of silicon, making it substantially paramagnetic.
Despite its complex mechanics, Rolex have succeeded in developing a movement that can comfortably fit inside a 10mm case. The Dynapulse escapement doesn’t take any more space than a conventional Swiss lever escapement.
What Does The Dynapulse Escapement Mean For Rolex?
Rolex bringing out the caliber 7135 with the novel Dynapulse escapement is a solid declaration of the fact that the tradition of innovation is very much alive at the brand, both in incremental upgrades and significant technical progression. The realization of complex escapement mechanisms, which has largely been restricted to artisanal level low-volume works, gets approval for mass production with the new Rolex Dynapulse escapement. The quality of its execution and the scalability of its realization merit the Dynapulse escapement as the most significant Rolex innovation of the 21st century and a potential catalyst for a watchmaking revolution at large.
How the Rolex Dynapulse escapement matures and morphs is something worthy to keep track of.
