Greubel Forsey has unveiled the GMT Quadruple Tourbillon – a horological heavyweight that combines its signature Quadruple Tourbillon and with their unique GMT watch. This is a timepiece with four tourbillons visible on the dial and two separate time zones indicated on two different dials and a 24 hour universal time display on the caseback.

Four tourbillons arranged in two pairs and two time zones on this dial

Robert Greubel and Stephen Forsey first unveiled the Double Tourbillon 30° in 2004. It consisted of a first cage, angled at 30°, that finished a rotation in one minute and was placed inside a second flat cage that performed a full rotation in four minutes.  The different speeds of the two cages helps cancel out the timing variations caused by the earth’s gravitational pull, thus ensuring accurate timekeeping. In 2005, they invented the Quadruple Tourbillon, which combined two sets of Double Tourbillon – a feat that established the watch as a key signature of this haute horology company. 

In 2011, the duo presented their take on a multiple time zone watch, the ingenious GMT timepiece, which was joined more recently by the GMT Earth. By reproducing the Earth's rotation in real time, this timepiece offered an intuitive view of time all over the world and a day/night indication.

How it was all put together on paper

And now in their GMT Quadruple Tourbillon, the Quadruple Tourbillon has been combined with a multiple time-zone display. The watch has an asymmetrical white gold case that measures a hefty 46.5 mm in width and 17.45 mm in height. Don’t try hiding this under your shirt cuff. It has a polished bezel and the caseband is hand-finished to a straight-grained effect. The proportions of the case were constructed to accommodate the high-domed sapphire crystal bezel and feature a lateral window on the caseband to view the earth’s equator and southern hemisphere.

Greubel Forsey timepieces are known for their movement and dial architecture. The main dial between 1 and 2 o’clock has a circular-grained and polished gold black-treated hour ring. It forms the highest point of the dial and underlines the asymmetrical shape of the case. A 72-hour power-reserve display is placed within this main dial.

The dial features many levels and high quality finishing

Below this level at 4 o’clock is placed a small seconds that shares its axis with a second time zone display adjustable in one-hour increments by means of a pusher. A rotating Earth is placed between 8 and 9, 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.

The four tourbillons are placed (in two pairs) on either side of the Earth. Featuring an open and transparent construction, the tourbillons are secured by flat black polished bridges and adorned with gold chatons as well as hand-polished beveling and countersinks.

The nickel silver bridges have a frosted finish

Flip the watch over to view the universal time 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 color; and those that do not (shown on a dark backdrop). The nickel silver bridges have a frosted finish and jewels are set in gold chatons. The movement, as you would expect from a Greubel Forsey timepiece, is finished to an extremely high standard.

The movement consists of 705 parts, of which 206 belong to just the four tourbillon cages. The spherical differential used by the four tourbillons is composed of 28 parts. The movement has a power reserve of 72 hours thanks to 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.

Paired with a black alligator leather strap, this watch is limited to just 66 pieces and the first 11 pieces will be made only in white gold. The watch is priced at $820,000.