Rotonde de Cartier Astrotourbillon

Rotonde de Cartier Astrotourbillon

At SIHH last week Cartier launched the new Rotonde de Cartier Astrotourbillon with their new manual winding movement, Caliber 9451 MC, designed and created by Cartier watchmakers. This unusual movement is the product of 5 years of development at the Cartier Manufacture in La Chaux-de-Fonds.

The Astrotourbillon’s carriage is driven by the third wheel of the gear train. The pinion of the escape wheel rotates around a fixed seconds-wheel (the fourth wheel of the gear train) in order to drive the escapement. The carriage has a special rotational axis, as it is positioned at the center of the movement. This requires a different gear-train design, from the two barrels of the movement through to the display of the minutes and hours. Another feature, responsible for the striking visual effect created by the movement, is that the balance staff and escape-wheel staff are not on the same rotational axis as the carriage. They are located to one side of the carriage, in linear alignment with its rotational axis. The tourbillon carriage is positioned “above” the movement between two dials, rather than being directly integrated into the movement as with classic tourbillons.

This construction is unusual and has both aesthetic and technical consequences. The elongated carriage makes a complete revolution around the entire surface of the dial in one minute. The off-center balance bridge, shaped like an arrow, indicates the seconds. In order to ensure the equilibrium of the carriage, it was necessary to incorporate a platinum counterweight on the opposite side of the carriage, hidden under the central dial. Furthermore, the weight of the carriage had to be limited (0.39 g for the entire carriage, excluding the counterweight) in order to control its inertia during rotation, hence the choice of titanium for its construction.

This new movement is housed in the 47 mm Rotonde de Cartier case, available in white or rose gold, priced as follows:

White gold, Ref. CRW1556204 – $133,000
Rose gold, Ref. CRW1556205 – $124,000

The Astrotourbillon will be available at select Cartier boutiques across the U.S. from June 2010, and Cartier is accepting pre-orders.

Additional technical information appears below the images, which may be enlarged with a click.

Rotonde de Cartier Astrotourbillon
Rotonde de Cartier Astrotourbillon

Rotonde de Cartier Astrotourbillon Watch

Case: 18 carat white or pink gold
Diameter: 47 mm
Crown: circular-grained in 18 carat white or pink gold, set with a sapphire cabochon
Crystal: sapphire
Case back: transparent sapphire crystal
Water resistance: 30 meters / 100 feet / 3 bar
Strap: black alligator skin (white gold) or brown alligator skin (pink gold)
Folding clasp: double adjustable, in 18 carat white or pink gold

Calibre 9451 MC Astrotourbillon

Movement: Cartier Manufacture, mechanical with manual winding, Astrotourbillon
Diameter: 16’’’ ¾, (38 mm)
hickness: 9.01 mm
Number of jewels: 23
Number of components: 187
Frequency: 21,600 vibrations/hour
Power reserve: approx. 48 hours
Individually numbered movement

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