A private collector graciously allowed me to play with some of his timepieces to photograph and review for TimeZone. He owns 16 exceptional timepieces and regularly wears each of them. He considers the platinum Invention Piece 1 to be one of his favourites for its creativity, craftsmanship, exclusivity and remarkably good looks.

Announced in 2008 with all 11 pieces long sold out, the Invention Piece 1 pays tribute to the atelier’s iconic Double Tourbillion 30° mechanism that took Robert Greubel and Stephen Forsey four years of research and development to realise. The dial architecture, indications and aesthetics are all modified and redeveloped around the original DT30°.

Greubel Forsey Invention Piece 1, Greubel Forsey Double Tourbillon 30°, Greubel DT30
Invention Piece 1 in platinum (No. 11 of 11)

The Movement: A Technical Milestone in Horology
The patented Calibre GF02N is a robust and accurate mechanical movement. The 38-jewel hand-wound movement comprises of 338 component parts, including a double tourbillon regulator and lever escapement. It is powered by two mainspring barrels with a 72-hour power reserve oscillating at 21,600 beats per hour.

The movement finishing and decoration are superb, with hand-bevelled tourbillon cage pillars, a solid gold counterweight plate, gold chatons and hand-polished screws. Not only is the GF02N a pleasure to look at, it is also a precision instrument.

The Double Tourbillon 30° mechanism derives its name from the 30-degree angle between the two tourbillon carriages, a one-minute tourbillon mounted inside a larger four-minute tourbillon. The double tourbillon was conceived specifically for the constant movements associated with a wristwatch and designed to improve the beat rate in all six positions.

Greubel Forsey Invention Piece 1, Caliber GF02N, Greubel Forsey Double Tourbillon 30°, Greubel DT30

Notably, when Abraham-Louis Breguet patented the tourbillon regulator over 200 years ago on 26 June 1801, the mechanism was designed to offset rate variations induced by shifts in the physical position of pocket watches. The tourbillon’s continuous rotation counteracts the effects of gravity on the balance of a pocket watch in its normal vertical position. However, once the pocket watch was removed from the vest pocket and laid flat with the dial up or down, the entire effect of the tourbillon was voided with no affect on the rate.

The philosophy behind the Double Tourbillon 30° is to average out positional errors on the oscillator by addressing the changes of rate from the horizontal and vertical positions. Indeed, Greubel Forsey found that the combination of the 30-degree inclination with the different rotational speeds of the two tourbillons improves timekeeping and chronometric performance when compared to a classical single-axis tourbillon or timepiece without a tourbillon.

Greubel Forsey Invention Piece 1, Greubel GF02N, Greubel Forsey Double Tourbillon 30°, Greubel DT30

In 2009, the Double Tourbillon 30° earned the Prix Gaïa for “Entrepreneurship” and, in 2010 it earned the Aiguille d’Or for best overall watch at the Grand Prix d’Horlogerie de Genève. Then, in 2011, the Double Tourbillon 30° was put through the ultimate accuracy and reliability test and proved its superior chronometric design by winning the International Chronometry Competition. During the rigorous competition, the timepiece was subjected to 15 days of tests at the Observatory in Besançon, France, then 15 days of tests at the COSC laboratory in Bienne, Switzerland, followed by exposure to a magnetic field and repeated shocks before undergoing yet another 15 days of tests at the COSC laboratory in Bienne. Overall, the Double Tourbillon 30° scored an exceptional 915 points out of a possible 1,000.

To this day, Greubel Forsey remains the only watch brand to have won these three prestigious awards.

Greubel Forsey Invention Piece 1, Greubel GF02N, Greubel Forsey Double Tourbillon 30°, Greubel DT30

Greubel Forsey Invention Piece 1, Greubel GF02N, Greubel Forsey Double Tourbillon 30°, Greubel DT30

The Dial
The level of hand-finishing is executed to the highest level, with a combination of frosted surfaces, straight-graining, flat black-polishing and bevelling that contributes to the dial’s dramatic visual effect. The exquisitely finished dial features a red triangular hours indication and blue triangular minutes indication that rotate in stacked, concentric circles to create a voluminous, three-dimensional architecture that showcases the Double Tourbillon 30° mechanism at the centre of the dial. The subsidiary seconds and power reserve indicator are located at the the top of the dial as if orbiting the double tourbillon cage.

Greubel Forsey Invention Piece 1, Greubel GF02N, Greubel Forsey Double Tourbillon 30°, Greubel DT30

Greubel Forsey Invention Piece 1, Greubel GF02N, Greubel Forsey Double Tourbillon 30°, Greubel DT30

Greubel Forsey Invention Piece 1, Greubel GF02N, Greubel Forsey Double Tourbillon 30°, Greubel DT30

Greubel Forsey Invention Piece 1, Greubel GF02N, Greubel Forsey Double Tourbillon 30°, Greubel DT30

Greubel Forsey Invention Piece 1, Greubel GF02N, Greubel Forsey Double Tourbillon 30°, Greubel DT30

Greubel Forsey Invention Piece 1, Greubel GF02N, Greubel Forsey Double Tourbillon 30°, Greubel DT30

Greubel Forsey Invention Piece 1, Greubel GF02N, Greubel Forsey Double Tourbillon 30°, Greubel DT30

Greubel Forsey Invention Piece 1, Greubel GF02N, Greubel Forsey Double Tourbillon 30°, Greubel DT30

In Motion
The dial architecture, indications and aesthetics accentuate the craftsmanship and hypnotic beauty of the double-axes tourbillon mechanism:

The Case
The massive platinum case measures 43.5mm and is finished with brushed and polished surfaces. The curved lugs are exceptionally comfortable on the wrist. The case is fitted with domed sapphire crystals that are treated with anti-glare on both sides. The sapphire crystal display back is secured by six screws for a water resistance of 30 meters.

Greubel Forsey Invention Piece 1, Greubel GF02N, Greubel Forsey Double Tourbillon 30°, Greubel DT30

Greubel Forsey Invention Piece 1, Greubel GF02N, Greubel Forsey Double Tourbillon 30°, Greubel DT30

Greubel Forsey Invention Piece 1, Greubel GF02N, Greubel Forsey Double Tourbillon 30°, Greubel DT30

The Caseback
The caseback is hand-hammered in bas-relief engraving with a “Message from the Inventor Watchmakers” that recounts the history of the Double Tourbillon 30°.

Greubel Forsey Invention Piece 1, Greubel GF02N, Greubel Forsey Double Tourbillon 30°, Greubel DT30
A “Message from the Inventor Watchmakers” is hand-hammered in bas-relief engraving

Greubel Forsey Invention Piece 1, Greubel GF02N, Greubel Forsey Double Tourbillon 30°, Greubel DT30

Greubel Forsey Invention Piece 1, Greubel GF02N, Greubel Forsey Double Tourbillon 30°, Greubel DT30
Calibre GF02N

The Fine Details
The timepiece is completed by a hand-sewn alligator strap with a platinum deployment clasp that is perfectly finished with mirror-polished and polished surfaces.

Greubel Forsey Invention Piece 1, Greubel GF02N, Greubel Forsey Double Tourbillon 30°, Greubel DT30
The hand-engraved “GF” initials on the deployment clasp

Greubel Forsey Invention Piece 1, Greubel GF02N, Greubel Forsey Double Tourbillon 30°, Greubel DT30

Greubel Forsey Invention Piece 1, Greubel GF02N, Greubel Forsey Double Tourbillon 30°, Greubel DT30
Steven wearing his Invention Piece 1

Jessica