The tourbillon is one of watchmaking’s most fascinating achievements. Effectively, it involves the balance rotating around its axis in a cage. This not only provides a visual spectacle on the dial: the constant rotation also reduces the influence of gravity on the oscillating system and increases the watch’s accuracy.
The Portugieser Tourbillon Rétrograde Chronograph (Ref. 3940)
This model combines a flying minute tourbillon at 6 o’clock with a retrograde date display at 9 o’clock and a flyback chronograph. The model is available in two versions, both limited to 50 watches. One is housed in an 18-carat Armor Gold® case with a blue dial featuring the maritime inspired design cues of the Boutique Editions. Thanks to its improved microstructure, this innovative new material has considerably higher hardness values than traditional 5N gold alloys. A second version is available in platinum.
The IWC-manufactured 89900 calibre is self-winding and builds up a power reserve of 68 hours. The chronograph displays stopped hours and minutes in a single totaliser at 12 o’clock. Thanks to its hacking tourbillon, the watch can be stopped completely, allowing the time to be set with down-to-the-second accuracy. The pallet lever and escape wheel are treated with Diamond Shell® technology, giving it an extremely hard surface that reduces friction and improves the flow of energy in the movement.
The Portugieser Perpetual Calendar Tourbillon (Ref. 5045)
This piece brings together the two complications that give the watch its name. Two References are available, both limited to 50 each. One will be available as a Boutique Edition with an 18-carat Armor Gold® case, while the second will be available in platinum.
The IWC-manufactured 51950 calibre combines a perpetual calendar with a tourbillon that has 82 individual parts and weighs only 0.635 grams. To make it visible at 12 o’clock, the calendar module’s advance ring was opened, and the moon phase integrated into the month display at 6 o’clock. With its 18-carat gold rotor, the automatic winding system builds up a large, seven-day power reserve. The perpetual calendar’s mechanical programme automatically recognises the different lengths of the months and adds an extra day at the end of February every four years. The moon phase display is so precise that it will need adjusting by one day after 577.5 years