SIHH 2011: Greubel Forsey Double Tourbillon 30° Technique in platinum
Double Tourbillon 30° Technique
in platinum
mechanical hand-wound movement, Calibre GF02 s
Double Tourbillon 30° • hour and minute display • outer tourbillon 4-minute rotation indicator
inner tourbillon 60-second rotation indicator • power-reserve indicator.
Movement with patented tourbillon
Movement dimensions
• Diameter: 38.40 mm
• Thickness: 12.15 mm
Number of parts
• Complete movement: 385 parts
• 2 tourbillon cages: 130 parts
• Weight of the two cages: 1.22 g
Number of jewels
• 43
• Olive-domed jewels in gold chatons
Power reserve
120 hours
Barrels
• Four coaxial series-coupled fast-rotating barrels (1 turn in 3.2 hours), one of which is equipped with a slipping spring to avoid excess tension
• Gold black chrome fi nished cover with relief engraving
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 Plates
Nickel silver, frosted with polished bevelling, nickel-palladium finish
Bridges
Nickel silver, frosted, spotted with polished bevelling, nickel-palladium finish, gold nameplate bearing the individual number
Gearing
• Involute circle profile
• Conical gearing with corrected profile
Inner Tourbillon
Inclined at a 30° angle, 1 rotation per minute
Outer Tourbillon
• 1 rotation in 4 minutes
• Hand-bevelled and openworked cage pillars
• Solid gold counterweight
Displays
• Hour and minute
• Small second
• 120-hour power reserve on a sector
• 4-minute outer tourbillon rotation indicator
Exterior
Case
• In platinum 950 with convex sapphire crystal
• Transparent back with sapphire crystal
• Raised polished engraving of the name of the Invention on a hand-punched background
• Gold security screws
• Three-dimensional, variable geometry-shaped lugs secured with screws
• 2 platinum engraved and hand-finished plates bearing text screwed to the caseband
• Hand-engraved individual number
Case dimensions
• Diameter: 47.50 mm
• Thickness: 16.84 mm
Water resistance of the case
3 atm - 30 m - 100 ft
Crown
Platinum with engraved and black
lacquered GF logo
Dial
• Sapphire crystal hour-ring
• Small second and power-reserve indicators in gold
Hands
• Hour and minute in gold, black chrome finish
• Small second, power reserve (red triangles)
• Sapphire crystal 4-minute engraved indicator
Strap and clasp
• Hand-sewn black, alligator
• Platinum 950 folding clasp, hand-engraved with the Greubel Forsey logo
Press Release
Can the buyer change the specifications?
Andrew,
Thanks. I note that this is a piece that is 'fun' for the wearer.
It is frustrating for the casual observer. Glancing at the dial (upside down) does not tell you anything.
Probably not for daily use (what shirt cuffs could cope?), just watching the two-speed tourbillons is justification to wear one. 
If, in addition, if there was substantative knowledge that the micro-engineering is justified by performance benefit, that would be the 'cherry on top' for this horological creamcake!
Can the buyer specify a different colour of hands? or does 'chrome black' gold actually give better contrast than is portrayed on the photograph?
Regards,
MTF
Having seen the watch on Monday (and hopefully I can post some
live pictures this evening), the watch is very readable with the black chrome. GF spend a great deal of time with prototypes and trying different set ups (aesthetics) to make sure the time is readable.
GF will consider individual requests, but as far as I know, if you do not like the platinum version, then there is always the white gold with the blacked background.
Will try and post pictures this evening so you can see.
Andrew H