Greubel Forsey GMT Quadruple Tourbillon Titanium Limited Edition

The GMT Quadruple Tourbillon by Greubel Forsey is now available in a titanium version. Limited to 11 pieces, this ground breaking horological marvel incorporates new materials, new colours and new finishes.

Greubel Forsey GMT Quadruple Tourbillon Titanium Limited Edition

The Quadruple Tourbillon is Greubel Forsey’s second Fundamental Invention and it averages out positional errors due to gravity in all situations, especially in stable wristwatch positions. To achieve this, the original tourbillon has been elevated to realise its full potential: inclined at 30°, doubled and then quadrupled.

The result, two synchronised Double Tourbillon 30° mechanisms, where a first cage, inclined at 30° and rotating in one minute, is nested within a second horizontal cage, completing a full rotation in four minutes. A spherical differential transmits the average timing rate of the four tourbillon cages, improving the overall chronometric performance of all the regulating organs.

Greubel Forsey GMT Quadruple Tourbillon Titanium Limited Edition

The 46.5mm case of the GMT Quadruple Tourbillon is made of titanium, which is both stronger and lighter than steel, while also being extremely resistant to corrosion and magnetic fields. This exclusive limited edition in titanium with striking blue accents ensures modern and dynamic feel on the wrist.

Greubel Forsey GMT Quadruple Tourbillon Titanium Limited Edition

The toughness of titanium presents a significant machining and hand finishing challenge for the components made from it, such as the GMT pusher or the folding clasp or the crown. In addition, new hand finishing details have been specially created for this timepiece.

The circular-grained hour ring with polished bevels and 72-hour chronometric power reserve indication appear for the first time in a brilliant blue. The mainplate is now frosted and spotted with polished bevelling, countersinks and straight-grained flanks, executed in a grey finish.

Greubel Forsey GMT Quadruple Tourbillon Titanium Limited Edition

Set near eight o’clock, the rotating terrestrial globe in blue livery offers the simultaneous display of several different time zones: on the dial side, with a 24-hour ring around the Earth, for Day/Night indication and on the caseback side, displaying 24 major cities their respective time zones while distinguishing between those which use summer time (on a light coloured backdrop), and those which do not (on a dark backdrop).

Greubel Forsey GMT Quadruple Tourbillon Titanium Limited Edition

The sapphire crystal window around the equator completes the timepiece, offering a complete view of the Earth in motion, with its continents immersed in the deep blue ocean waters, complementing the exquisite blue finish of the power reserve, hour circle and strap.

Greubel Forsey GMT Quadruple Tourbillon Titanium Limited Edition

Technical details

Model: GMT Quadruple Tourbillon
Edition: 11 pieces in titanium

Movement

Hand-wound movement with 3 patents

Movement dimensions
• Diameter: 39.50mm
• Thickness: 13.00mm

Number of parts
• Movement: 705 parts
• Four tourbillon cages: 260 parts
• Total weight of the cages: 2.25g
• Spherical differential: 28 parts

Number of jewels
• 84
• Olived-domed jewels in gold chatons

Chronometric power reserve
• 72 hours

Barrels
• Three 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 white gold mean-time screws (10.70mm diameter)

Frequency
• 21’600 vibrations/hour

Balance spring
• Phillips terminal curve
• Geneva-style stud

Main plates
• Nickel silver, frosted and spotted with polished bevelling and countersinks, straight-grained flanks, grey treatment

Bridges
• Nickel silver, frosted and spotted, polished bevelling and countersinks, straight-grained flanks, grey treatment
• Gold plate engraved with the individual number
• Flat black polished gold plates with relief engraved text, polished bevelling and countersinks, straight-grained flanks
• Four flat black polished steel tourbillon bridges, hand-polished bevelling and countersinks, straight-grained flanks

Inner tourbillons
• Inclined at a 30° angle, 1 rotation per minute

Outer tourbillons
• 1 rotation in 4 minutes
• Hand-bevelled and open-worked cage pillars
• 1 gold counterweight per double cage bearing the individual number of the timepiece

Gearing
• Involute circle profile
• Conical gearing with profiled teeth

Displays
• Hours and minutes
• Small seconds (mean performance)
• 72-hours power reserve on a sector
• 2nd time zone GMT
• 24 time zones universal time
• Rotating titanium globe with universal time
• Cities observing summer time
• Day-and-night

Exterior

Case
• In titanium with asymmetrical convex synthetic sapphire crystal
• Transparent back with asymmetrical convex synthetic sapphire crystal
• Lateral window with shaped synthetic sapphire crystal
• Three-dimensional, variable geometry-shaped lugs
• Raised polished engraving “GMT Quadruple” and “Greubel Forsey” on a hand-punched background
• Gold security screws
• Polished bezel, caseband with hand-finished straight graining
• Titanium GMT pusher with raised engraving on a hand-punched background
• Engraved individual number

Case dimensions
• Diameter: 46.50mm
• Height: 17.45mm

Water resistance of the case
• Water-resistant 3atm – 30m – 100ft (standard NIHS 92-20/SN ISO 22810:2010)

Crown
• In titanium with engraved GF logo

Dial
• Multi-level in gold, anthracite colour
• Gold hour-ring and power reserve, circular-grained with polished bevelling, blue treatment
• Gold hour markers
• GMT in gold, hand matt lapped
• Small second, circular-grained

Hands
• Hours and minutes in polished gold, with Super-LumiNova
• Small seconds in polished steel, black treatment
• Power-reserve in polished steel, hand-polished countersink
• 2nd time zone GMT indicator, red

Strap and clasp
• Rubber or hand-sewn alligator
• Titanium folding clasp, engraved with the GF logo