The Earth turns and Greubel Forsey keeps moving. Today, the Atelier unveils the third terrestrial interpretation of its GMT Earth. This unique and now even more modern creation features a new titanium case and is adorned with an even more elegant intense black finish: limited edition of 11 pieces.
The Earth is a global village that man cannot explore in a single glance: the vastness of its spaces and curved geometry present us with a never-ending horizon. At least, until now. With 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.
A third version in Titanium
The first version of the Greubel Forsey 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.
A clear and intuitive display
The Greubel Forsey 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.
Finally 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 tourbillon 24 seconds, an unrivalled invention
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.
Greubel Forsey GMT Earth The Final Edition Technical Specifications
GMT Earth – Limited edition of 11 pieces in titanium
Hand-wound movement with 3 patents
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
Movement
Movement dimensions
• Diameter: 36.40mm
• Thickness: 11.55mm
Number of parts
• Movement: 453 parts
• Tourbillon cage: 86 parts
• Weight of the cage: 0.39g
Number of jewels
• 60
• Olived-domed jewels in gold chatons
Chronometric power reserve
• 72 hours
Barrels
• Two coaxial series-coupled fast-rotating barrels (1 turn in 3.2 hours), one of which is equipped with a slipping spring to avoid excess tension
Balance wheel
• Variable-inertia with gold mean-time screws (10mm diameter)
Frequency
• 21’600 vibrations/hour
Balance spring
• Phillips terminal curve
• Geneva-style stud
Main plate
• Nickel silver, frosted and spotted with polished bevelling and countersinks, straight-grained flanks, black treatment
Bridges
• Nickel silver, frosted with polished bevelling and countersinks, straight-grained flanks, black treatment
• Flat black polished steel tourbillon bridge, hand-polished bevelling and countersinks
• Flat black polished steel screws, blued by heat treatment
Tourbillon
• Inclined at a 25° angle, 24-seconds rotation
• Light alloy cage pillars
• Titanium cage bridges
• Gold counterweight
Gearing
• Involute circle profile
• Tangential inclined gear on fixed wheel
and profiled teeth on escape wheel pinion
Displays
• Hours and minutes
• Small seconds
• 72-hours power reserve on a sector
• 2nd time zone GMT
• 24 time zones universal time
• Rotating titanium globe with universal time
• Complete view from North Pole to South Pole
• Summer time
• Day-and-night
Exterior
Case
• In titanium, with titanium plates, engraved, hand-finished with text, screwed to the caseband
• Lateral window with shaped synthetic sapphire crystal
• Three-dimensional, variable geometry-shaped lugs
• Three-dimensional synthetic sapphire crystal caseback, with integrated dome
• Three-dimensional, asymmetrical, synthetic sapphire crystal bezel
• Raised polished engraving “GMT Earth” and “Greubel Forsey” on a hand-punched background
• Gold security screws
• Titanium GMT pusher with raised engraving on a hand-punched background
• Engraved individual number
Case dimensions
• Diameter: 45.50mm
• Height: case 16.18mm (height on synthetic sapphire dome 18.00mm)
Water resistance of the case
• Water-resistant 3atm – 30m – 100ft (standard NIHS 92-20/SN ISO 22810:2010)
Crown
• In titanium, synthetic sapphire insert with GF logo
Dial Side
• 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
Movement Side
• Synthetic sapphire disc displaying city names surrounded by 2 gold rings (UTC and summer time) engraved and lacquered
• Gold “summer time” plate with individual number, raised engraving
• South Pole of the globe with UTC indicator, engraved and lacquered, hand matt lapped
Hands
• Hours, minutes, small seconds and power-reserve in polished steel, hand-polished countersinks
• 2nd time zone GMT indicator, red triangle
Strap and clasp
• Rubber or hand-sewn alligator
• Titanium folding clasp, engraved with the GF logo
