ith the GMT Earth, Greubel Forsey has created a watch that, for the first time, makes it possible to appreciate the entirety of the world in a single glance. This technical feat first appeared in 2011. At the time of the first “GMT”, the Earth was not yet fully revealed.
Seven years later, the design of the Earth was finally complete: visible from all angles in its new sapphire alcove, it appears as though it is floating in space. On the front as well as the back, the laser-engraved Earth shows world times that are both quick and easy to read.
The first version of the GMT Earth was in white gold. The second, in platinum. Today, this timepiece is available with a new titanium case. Almost twice as light as steel, it is impervious to temperature variations, non-magnetic, hypoallergenic and eight times stronger than gold or platinum, but requires extremely technical know-how and equipment to be manufactured and finished.
The GMT Earth in titanium will be available in a limited edition of 11 pieces, three times less than the original version. Weighing just 117g, the weight of the strap has been reduced by two-thirds. The case has lost just over a third of its weight. Titanium is used not only for the entire case, but also the bridges, the GMT push-piece, the crown and the folding buckle, the latter two being the components most exposed to shocks and scratches.
To accompany the light and matt tones of titanium, Greubel Forsey opted for a black finish on the dial. It is applied to the spotted bottom plate and to all the frosted bridges, with straight flanks, polished bevelling and countersinks. This finish is also featured on an all-black natural rubber strap, whose inner face is engraved with the cardinal values of the Greubel Forsey Atelier and which are visible on the bezel.
The GMT Earth displays four key pieces of information on its dial side. The first is the off-centre hours, minutes and seconds display. The first two feature large openworked hands finished with a Super-LumiNova tip, complemented by a small seconds hand on a sapphire disc at three o’clock.
On the left is the GMT indicator, whose red hand effortlessly stands out against a hand-engraved black gold disc filled with lacquer. The third, located opposite the crown, is the power reserve, designed following the same process: a black, engraved gold segment, filled with lacquer and covered by a silver-polished steel hand.
Between 7 o’clock and 9 o’clock, the Earth occupies the largest space, completing a full rotation in 24 hours. The engraved sapphire ring around the equator acts as a day / night indication and allows you to instantly see which hemisphere is in the daytime and which is at night.
Located on the side of the caseband, a final window opens to show the equator. Thanks to this, the Earth really can be seen from all angles. Finally, on the caseback side, the worldtime display indicator completes the design. 24 time zones indicate the UTC of 24 major cities - with those that observe daylight savings on a white background.
The GMT Earth boasts Greubel Forsey’s third invention. The Tourbillon 24 Secondes uses a fast rotation speed and is set at an angle to resolve the positioning problem in relation to gravity and which is crucial for the operation of the oscillator. The 25° angle and the rapid rotation of the tourbillon cage significantly improve the chronometric performance of a system containing only one tourbillon, especially those in fixed positions.
FUNCTIONS GMT • 2nd time zone • rotating globe with universal time and day-and-night • complete and global view from northern to southern hemisphere • universal time on 24 time zones • summer and winter time • cities observing summer time • lateral window showing the equator • GMT pusher • Tourbillon 24 Secondes • hours and minutes • small seconds • power-reserve
CASE In titanium, with titanium plates, engraved, hand-finished with text, screwed to the caseband • Three-dimensional, asymmetrical, synthetic sapphire crystal bezel
CASE DIMENSIONS Diameter: 45,50mm • Height: 16,18mm (height on synthetic sapphire dome 18.00mm)
WATER RESISTANCE Water-resistant 3atm - 30m - 100ft
DIAL Multi-level hour-ring in synthetic sapphire, galvanic growth hour indexes, engraved and lacquered minutes and small seconds • Power-reserve and GMT indicators in gold, engraved and lacquered, circular-grained, black treatment • Rotating globe with day-and-night UTC indicator in synthetic sapphire, engraved and lacquered
STRAP AND CLASP Rubber or hand-sewn alligator • Titanium folding clasp, engraved with the Greubel Forsey logo