Replica Audemars Piguet released its first Royal Oak Concept watch in 2002 with a case made of Alacrite 602. Another Concept model, in 2008, featured a forged carbon case, and the 2011 model combined a titanium case with a black ceramic bezel. Ahead of the 2014 SIHH watch fair in January, AP has unveiled the newest in the series, the Royal Oak Concept GMT Tourbillon, which adds a white ceramic bezel to the titanium case.
The Audemars Piguet Royal Oak Concept GMT Tourbillon features a bezel, crown and push-pieces in white ceramic (replacing the 2011 model’s black ceramic), contrasting with the sculpted titanium case middle. Audemars Piguet has also incorporated ceramic into the movement itself, using the material for the hourglass-shaped upper bridge, which serves to highlight the symmetry of the watch’s main attractions, its tourbillon and GMT display. Both are visible through the open dial, another hallmark of the Audemars Piguet Royal Oak Concept series, which was initially launched as a tribute to the Royal Oak’s 30th anniversary.
Creating the watch’s white ceramic parts was a complex and time-consuming process, AP says, because ceramic is almost nine times harder than steel and virtually scratch-proof. Special milling-cutter machines equipped with diamond-tipped tools were required (ceramic can only be scratched by diamonds) for the process; each bezel takes about eight hours to make, compared to 45 minutes or so for a comparable bezel made of steel.
The watch’s 44-mm-diameter case is made of titanium, a metal prized for its toughness and lightness (twice as light as steel) and is more rounded than a typical Royal Oak case, the better to highlight the model’s famous octagonal bezel with eight hexagonal screws. The inner flange encircling the dial is made of lightweight anodized aluminum. (Click the photo for a larger image.)
Audemars Piguet Royal Oak Concept GMT Tourbillon
The characteristic that has defined Audemars Piguet’s Concept watches, the integration of case and movement, is also on display in this new model. The movement, hand-wound Calibre 2930, features a twin barrel that provides a 10-day power reserve, providing energy for the tourbillon and second time-zone (GMT) display. The escapement, which beats at a frequency of 21,600 vph (3 Hz), rotates inside the tourbillon carriage every 60 seconds. The tourbillon cage is made up of 85 components, yet weighs only .45 grams. Each cage requires three days to assemble, including two full days to install, and the entire mechanism represents more than two full weeks of work. Each component is beveled, polished, assembled and balanced by hand. Fake Audemars Piguet’s proprietary parallel double barrel system generates a constant force during some 237 hours of autonomy, enhancing timekeeping precision.
The GMT display at the 3 o’clock position, which shows the time in a second time zone, is adjusted using the push-piece at 4 o’clock: each push advances the time by one hour. This indicator, based on 12 hours, combines two superimposed disks. The first, on which the figures are inscribed, completes one turn every 12 hours. The second, just below it, completes one turn every 24 hours and is divided into two colored halves that indicate whether it is daytime (white) or nighttime (black).
The energy from Caliber 2930’s two 10-day barrels is fed into the gear train at the same time by means of a single pinion bridging the two. Audemars Piguet says that this is a gentler means of transmitting energy than the more common system of two series-linked five-day barrels. It also reduces pressure in the gearing, with the friction in the barrels offsetting torque variations, and gives increased running precision, greater power reserve and enhanced reliability, according to AP.
The Royal Oak Concept GMT Tourbillon also features a selection-indicator mechanism. According to the position of the winding stem, the hand positioned on the dial at 6 o’clock indicates its selected function. The “H,” “N,” and “R” indications correspond to the three positions, standing for time-setting, neutral, and winding, respectively.
The watch is on a white rubber strap, which matches the white ceramic bezel, push-pieces and crown and is integrated into the distinctive octagonal case.