Here’s a quick peek behind the curtain, as I’m starting to write this article I have just finished working on the Breguet Marine Tourbillon Equation Marchante 5887 article so my brain is already full of the high end scientific principles at play in that watch. Now we move to an equally technical and astonishing watch in the form of the Greubel Forsey Nano Foudroyante EWT, which they’ve released for their 20th anniversary. If you think that name is confusing, worry not, let’s break it down and understand it together.
Let’s start with ‘Foudroyante’, which is a rare watchmaking term that actually has a relatively simple definition. It’s a seconds function capable of displaying fractions of a second. The most common (if such a thing can be said of a rare complication) way to achieve this is by having a seconds subdial with a seconds hand that rotates 360 degrees in one second. When moving so fast it’s virtually impossible to achieve a smooth rotation and so the second is split into fractions with the hand moving in beats. The Habring2 Foudroyante for example has eight intervals while the Greubel Forsey Nano Foudroyante EWT has just six.
You can see the seconds display on the tiny subdial mounted on the flying tourbillon (Greubel Forsey’s first) at 5 o’clock. It has to be mounted there because the Foudroyante is basically converting the impulses of the balance directly into timekeeping information. What that means though is that as the tourbillon rotates, so does the subdial. Which would be problematic except that Greubel Forsey have implemented an oriented reading axis similar to the planetary gearing found on the Atowak Cosmofleet that keeps the display level for optimal readability.
As you might expect, creating a hand that rotates once per second on top of a flying tourbillon is incredibly energy intensive. That’s where the next part of Nano Foudroyante EWT’s name comes into play, ‘nano’. This watch is a proof of concept that nanomechanics is practical in watchmaking, pushing miniaturisation of components beyond the micro scale to the nanometric scale. What this means is that the watch is capable of managing energy on the nanojoule scale, greatly increasing the foudroyante function’s energy efficiency by a factor of 1,800 compared to previous examples.
In theory this extends the power reserve. However, somewhat frustratingly GF have only supplied the power reserve data with the chronograph (we’ll get to that shortly) engaged, which is only 24-hours. We simply don’t know if the power reserve is longer if the chrono isn’t engaged. Also 24 hours is exceptionally low for a power reserve but perhaps that can be forgiven due to the watch’s experimental/concept status.
A side effect of having such small components is that the movement is itself very svelte. In turn that means the case, which is made from a combination of white gold and tantalum, measures just 37.9mm in diameter. That’s the smallest watch Greubel Forsey have ever produced in their 20 years of operation. Oh yes, this watch is so complex that it’s only now that I have a moment to address the fact that this is GF’s 20th anniversary celebratory timepiece.
But wait, there’s more. As hinted at earlier, on top of the incredible Nano Foudroyante display Greubel Forsey have pushed the boundaries even further by adding a monopusher flyback chronograph into the mix. Which is yet another milestone because this is the first time they’ve created a flyback chronograph on a manual-winding movement. The chronograph consists of a central 60-second chronograph hand and a 60-minute chronograph counter at 9 o’clock. Below that chronograph subdial is a small seconds subdial, which is useful for knowing which of the 60 seconds in a minute the Nano Foudroyante dial is currently showing.
Bringing us to the end of the article is the final part of the watch’s name, ‘EWT’, which is an acronym for ‘Experimental Watch Technology’. More or less telling us that this is a concept watch. However, unlike many concept watches it is actually for sale in a limited edition of 11 pieces at a substantial price of CHF 465,000 (approx. £410,000). Considering the degree of innovation and precision on display here, that makes sense.
Price and Specs:
More details at Greubel Forsey.
