Greubel Forsey GMT Quadruple Tourbillon. Robert Greubel and Stephen Forsey makes a bold move combining their second Fundamental Invention, the Quadruple Tourbillon originally introduced in 2005, with their jaw-dropping interpretation of the GMT with its outsized rotating globe. Displaying three time zones along with a universal time function, the GMT Quadruple Tourbillon is distinguished by its three-dimensional architecture.
Robert Greubel and Stephen Forsey makes a bold move combining their second Fundamental Invention, the Quadruple Tourbillon originally introduced in 2005, with their jaw-dropping interpretation of the GMT with its outsized rotating globe.
Displaying three time zones along with a universal time function, the Greubel Forsey GMT Quadruple Tourbillon is distinguished by its three-dimensional architecture and the imposing asymmetrical case (46.50 mm x 17.45 mm).
Secured by flat black polished bridges and adorned with gold chatons, the four tourbillons are constructed in pairs within a unique system of compact cages. 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.
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 3 Hz (21,600 vph) hand-wound calibre comprising 805 parts, including three fast-rotating barrels.
The dial is all built on different levels with the highest point being the main hours/minutes dial between 1 and 2 o’clock, complemented by a 72-hour chronometric power-reserve display.
The next level, at 4 o’clock, is represented by the coaxial small seconds and second time zone display which is adjustable in one-hour increments by means of a pusher.
The Earth in motion, surrounded by a fixed 24 hours ring around the Equator and displaying local time for all the longitudes, can be admired between 8 and 9 o'clock. A lateral window in the asymmetrical section of the case provides a view of the Equator and the Southern hemisphere.
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 GMT Quadruple Tourbillon 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. Price on request. greubelforsey.com
Displaying three time zones along with a universal time function, the Greubel Forsey GMT Quadruple Tourbillon is distinguished by its three-dimensional architecture and the imposing asymmetrical case (46.50 mm x 17.45 mm).
Secured by flat black polished bridges and adorned with gold chatons, the four tourbillons are constructed in pairs within a unique system of compact cages. 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.
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 3 Hz (21,600 vph) hand-wound calibre comprising 805 parts, including three fast-rotating barrels.
The dial is all built on different levels with the highest point being the main hours/minutes dial between 1 and 2 o’clock, complemented by a 72-hour chronometric power-reserve display.
The next level, at 4 o’clock, is represented by the coaxial small seconds and second time zone display which is adjustable in one-hour increments by means of a pusher.
The Earth in motion, surrounded by a fixed 24 hours ring around the Equator and displaying local time for all the longitudes, can be admired between 8 and 9 o'clock. A lateral window in the asymmetrical section of the case provides a view of the Equator and the Southern hemisphere.
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.
COMMENTS