GREUBEL FORSEY – GMT Quadruple Tourbillon White Gold Edition 2019
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Four tourbillons orbiting the Earth
Robert Greubel and Stephen Forsey have shown creative daring and boldness in uniting their second Fundamental Invention, the Quadruple Tourbillon, with their ground breaking interpretation of the GMT with its outsized rotating globe.
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Displaying three time zones along with a universal time function,
this exceptional timepiece is distinguished by its three-dimensional
architecture created with extreme attention to fine craftsmanship. A Unique edition of 66 pieces in total, the first 11 of which are in white gold.
Huygen’s invention of the hairspring in
1675 was a milestone in the watchmakers’ long-running quest for precision. It did not however eliminate the issue of gravity, which is detrimental to the timing of watches, particularly in vertical positions. To seek to remedy this,
Abraham-Louis Breguet (
1747-1823) conceived the idea of housing the regulating organ (hairspring, balance wheel and escapement) within a rotating cage.
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By turning around its axis, generally in one minute, the cage carried the ‘heart’ of the watch through different successive positions, thereby averaging out timing variations. The tourbillon was born (
1801). Striving to improve chronometry still further,
Robert Greubel and
Stephen Forsey re-imagined the tourbillon principle and then developed their first three Fundamental Inventions: the
Double Tourbillon 30° (
2004), the
Quadruple Tourbillon (
2005) and the
Tourbillon 24 Secondes (
2006).
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In their
GMT Quadruple Tourbillon, the two watchmakers have chosen to revisit their second invention and to take it even further by combining it with a multiple time-zone display. This is a nod to both history and technology, since the ingenious device created to compensate for the effects of gravity… actually gravitates around the Earth – four times over!
A highly complex mechanism
Working on the principle that the more different positions the regulating organ moves through, the more precise the timekeeping will be,
Robert Greubel and
Stephen Forsey invented the
Quadruple Tourbillon with a spherical differential. Right from the original idea the concept was clear. While coupling four separate tourbillons would have been challenging, they sought a more compact solution. To save space in all three dimensions, they chose to construct the tourbillons in pairs within a unique system of compact cages, an extremely challenging feat.
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Each of these two systems is modelled on the
Double Tourbillon 30°, with a first cage rotating in one minute and angled at
30°, fitted inside a second upright cage performing a full rotation in four minutes. The combination of the inclination of the inner cage and the different rotational speeds of the two cages focuses on cancelling out the timing variations due to the earth’s gravitational attraction in all the usual positions a wristwatch can adopt, particularly in stable positions. The spherical differential serves to average the timing of the two autonomous oscillators and thus improve chronometric performance, a system for which two patents have been filed.
Bringing the planet to the wrist
Having mastered the tourbillon,
Robert Greubel and
Stephen Forsey have continued to investigate and reinterpret other horological mechanisms, notably a practical and much appreciated complication: simultaneous multiple time zones display.
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In
2011,
the two Inventor Watchmakers expressed their own vision of this modern
day function in the ground breaking timepiece aptly named the GMT, more
recently joined by the GMT Earth. In this patented system, the second
time zone indication on a separate subdial is paired with a universal
time display providing an intuitive reading of the time around the world
thanks to a world first: an outsized globe completing one full rotation
every 24 hours, following planet Earth itself.
An impressive three-dimensional sight
In bringing the
Quadruple Tourbillon and the GMT mechanisms together,
Greubel Forsey not only accomplished a major technical feat that led to the creation of a new hand-wound calibre comprising
705 parts, including three fast-rotating barrels. The Inventor Watchmakers also tackled this challenge from an architectural angle to create a timepiece in which the three-dimensional approach is expressed on many levels. The main hours/minutes dial between 1 and 2 o’clock forms the highest point of the dial, where it is underlined by the subtle asymmetry of the case and complemented by a 72-hour chronometric power-reserve display. The next level is it at 4 o’clock, with the coaxial small seconds and second time zone display which is adjustable in one-hour increments by means of a pusher.
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Located between 8 and 9 o’clock, observers can admire the spectacular sight of the Earth in motion, surrounded by a fixed 24 hours ring around the Equator and displaying local time for all the longitudes – simultaneously taking account of the day/night indicator (on respectively light/dark zones).
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A lateral window in the asymmetrical section of the case provides an
unprecedented view of the Equator and the Southern hemisphere. The four
tourbillons gravitate in two pairs on either side of the blue planet,
each featuring an open and transparent construction, secured by flat
black polished bridges and adorned with gold chatons as well as
hand-polished bevelling and countersinks. A truly enchanting and
exquisitely light choreography.
A practical but refined case back
Universal time is visible through the case back, with a fixed 24-hour scale bearing day/night zones and a disk with three-letter abbreviations of 24 cities representing the various time zones. This disk also distinguishes between the time zones that implement Summer Time (Daylight Saving Time) appearing in a light colour; and those that do not (shown on a dark backdrop). The case back also provides a chance to admire the Quadruple Tourbillon as well as frosted bridges with jewels set in gold chatons. The two complex asymmetrical convex sapphire crystals protecting the dial and case back also called for the utmost expertise.
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This masterpiece of contemporary aesthetics comes in a unique edition of
66 pieces. The first
edition of
11 of which are in white gold, numbered from
01/11 to
11/11 on a plate in the centre of the dial. The
GMT Quadruple Tourbillon: a new encounter between technical complexity and aesthetic audacity, signed
Greubel Forsey.
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TECHNICAL SPECIFICATIONS
Collection: GMT Quadruple Tourbillon
- GMT Quadruple Tourbillon - Unique edition of 66 pieces
11 pieces in white gold
Hand-wound movement with 3 patents
• GMT • 2nd time zone • rotating globe with universal time and day-and-night
• universal time on 24 time zones • cities observing summer time
• lateral window showing the equator and southern hemisphere
• GMT pusher • Quadruple Tourbillon • hours and minutes
• small seconds • power-reserve
Movement
Dimensions
• Diameter : 39.50 mm
• Thickness : 13.00 mm
Number of parts
• Movement:
705 parts
• Four tourbillon cages:
260 parts
• Total weight of the cages: 2.25 g
• 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 (10.70 mm 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, nickel-palladium treatment
Bridges
• Nickel silver, frosted and spotted, polished bevelling and countersinks,
straight-grained flanks, nickel-palladium 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 openworked cage pillars
• 1 gold counterweight per double cage bearing the individual number
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 white gold 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
• White gold GMT pusher with raised engraving on a handpunched background
• Hand-engraved individual number
Case dimensions
•
Diameter : 46.50 mm
• Height : 17.45 mm
Water resistance of the case •
Water-resistant 3 atm - 30 m - 100 ft
(standard
NIHS 92-20/SN ISO 22810:2010)
Crown
• In white gold with engraved and black lacquered
GF logo
Dial
• Multi-level in gold, anthracite colour
• Gold hour-ring, circular-grained with polished bevelling, black treatment
• Gold hour markers
• Power-reserve and 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
• Hand-sewn alligator
• White gold folding clasp, hand-engraved with the
GF logo
Unique edition
Limited Edition of
66 pieces.
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Press Release -
2019
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GREUBEL FORSEY SA
For further information:
Communication Department
press@greubelforsey.com – +
41 79 194 2884
Eplatures-Grise -
16 P.O. Box
670
2301 La Chaux-de-Fonds -
Switzerland
+41 32
925-4545
+41 32
925-4502
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