Greubel Forsey introduces GMT Quadruple Tourbillon, a timepiece that combines the unbelievable titanium-globed multiple time zone complication from the GMT Earth and the brand’s second fundamental invention, the Quadruple Tourbillon.

Greubel Forsey GMT Quadruple Tourbillon on the wrist

Combining these two stunning elements into one watch is incredibly challenging: necessitating the creation of a whole new caliber, the Quadruple Tourbillon GMT demonstrates (again) the mastery of this brand when it comes to the architectural art of precision timekeeping.

GMT the Greubel Forsey way

Robert Greubel, Stephen Forsey, and their team never, ever do anything the way other brands do. So it stands to reason that adding a time zone feature to a Greubel Forsey watch would not be simple – but it would be practical. The Quadruple Tourbillon GMT arose from Greubel and Forsey feeling the need to reinterpret horological mechanisms outside the tourbillon after having focused on that for so long.

Side by side: Greubel Forsey GMT Quadruple Tourbillon (left) and GMT Earth

The “GMT” in the GMT Quadruple Tourbillon derives from 2011’s patented GMT and 2018’s GMT Earth, both of which significantly raised the bar for the GMT complication. This function displays two additional time zones (for a total of three shown on the watch) in addition to an intuitive universal world time function graphically displayed by a large hand-painted titanium globe completing a full rotation once every 24 hours (thereby mimicking the earth in miniature).

While on the GMT Earth the dial’s globe extended to the rear of the movement to include the southern hemisphere and Antarctic, that was not possible on the Quadruple Tourbillon GMT due to the four tourbillons; instead the bottom of the globe is covered by the display of the world time cities.

View though the display back of the Greubel Forsey GMT Quadruple Tourbillon

Most of the southern hemisphere and equator are visible from the  sapphire crystal side window, while the northern hemisphere is visible from the dial.

Greubel Forsey’s Quadruple Tourbillon

The white gold-encased Quadruple Tourbillon à Différentiel Sphérique, introduced in 2005, features four revolving tourbillon carriages within just one movement, an invention patented by the duo in 2004.

The premise of all three of the duo’s first fundamental inventions – the Double Tourbillon 30°, the Quadruple Tourbillon, and the Tourbillon 24 Secondes – is to improve the precision of the tourbillon. As the tourbillon’s inventor, Abraham-Louis Breguet, conceived the idea patented in 1801 for pocket watches, which remain in one position only, Greubel Forsey permanently strives to make the tourbillon as effective as possible for the wristwatch, which continuously finds itself in different positions.

Greubel Forsey Quadruple Tourbillon Blue in red gold

The Quadruple Tourbillon returned in 2009 in red gold and then again in 2017 with platinum and all-black versions, followed a year later by the astounding Quadruple Tourbillon Blue, whose beautiful, perfectly black-polished dial pretty much overshadowed the technical prowess of the tourbillon invention – if that were even possible.

The premise of the Quadruple Tourbillon remains the same since day one: the four tourbillons are arranged in pairs within a system of compact cages and connected by a spherical differential. Each of the two systems is modeled on the Double Tourbillon 30°, comprising a first tourbillon cage angled at 30 degrees and making “normal” one-minute revolutions inside a second cage taking four minutes to perform a complete revolution.

The combination of inclinations and different rotational speeds averages out positional variations in timing, while the differential averages the timing of each of the tourbillon pairs. Two patents have been awarded for this high-precision system.

Greubel Forsey GMT Quadruple Tourbillon

GMT Quadruple Tourbillon: putting it all together

What draws the eye in first? The titanium globe or the tourbillons dancing their mechanical ballets in their cutaways? Or is it the stunning three-dimensional architecture of the case, dial, and everything in between?

Looking over the entire watch there is plenty to be impressed by: the two double tourbillons flanking the globe while spinning on multiple axes; the clean, modern design of the numerals and indications; the black-polished tourbillon bridges; the perfect finishing visible on every millimeter of the entire movement.

Greubel Forsey GMT Quadruple Tourbillon

However, in my humble opinion, the most interesting focal point is the three-dimensional globe at 8 o’clock as it’s a premium example of the intuitive way a world time watch can look when a master of detail like Greubel Forsey gets its hands on it.

And combining this fascinating GMT complication with the Quadruple Tourbillon system was a major feat, leading to the creation of a new hand-wound caliber comprising 805 components.

A close look at the dial side of the Greubel Forsey GMT Quadruple Tourbillon

The architectural case takes its cue more from the GMT Earth model, which had whittled the bulges seen in the original GMT model down from three to one big one to accommodate – and allow a full view of – the titanium globe. While it may look at first glance like there are two asymmetric bulges on this new watch’s case, I would describe them as one jutting out from the case surrounding the globe with a just barely discernible hint of another to highlight the subdial displaying the most important piece of information here: the time. The bulges are used to draw the eye quickly to the right places to get the most basic information first.

Greubel Forsey GMT Quadruple Tourbillon

Greubel Forsey rearranged the volumes and surfaces of the freshly combined elements according to a new technical and aesthetic structure, making the entirety of this watch very three-dimensional with the highest part of the dial is capped by the subdial for hours and minutes. The back is equally as enchanting with its fixed 24-hour scale with day/night zones and 24 abbreviated world cities, each representing a time zone. The time zone disk also gives us information on Daylight Savings Time.

But perhaps even more fun is the opportunity to admire the perfectly finished Quadruple Tourbillon and the gorgeous frosted bridges with their chaton-encased bearing jewels. Greubel Forsey is known for its exquisite finishing, widely lauded as achieving some of – if not the – best in the industry. Every component is perfect, with not a speck of dust or minute scratch to be found within a Greubel Forsey timepiece.

Greubel Forsey GMT Quadruple Tourbillon wristshot

It might seem a bit exaggerated to maintain a workshop Greubel Forsey’s size for an output of one to two timepieces per month, but when you inspect this timepiece you understand why that is.

“This is not a world of marketing strategy and sales plans,” Stephen Forsey once explained to me. “This is first and foremost about two men who are passionate about watchmaking.”

For more information please visit www.greubelforsey.com/en/collection/gmt-quadruple-tourbillon-2/.

Quick Facts Greubel Forsey GMT Quadruple Tourbillon
Case: 46.5 x 17.45 mm, white gold
Movement: manual winding GF caliber with four tourbillons arranged in two sets; 805 components; variable inertia balance; three serially operating fast-rotating spring barrels; 72-hour power reserve 3 Hz/21,600 vph frequency
Functions: hours, minutes, small seconds; power reserve indication, second time zone adjustable in one-hour increments, world time with Daylight Savings Time, day/night indication
Limitation: 11 pieces in white gold; 66 pieces in total to be released
Price: 780,000 Swiss francs excluding applicable taxes

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