The Portugieser Perpetual Calendar Tourbillon (Ref. 5045) brings together the two complications that give the watch its name. 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.
IWC Portugieser Perpetual Calendar Tourbillon IW504505
One of IWC’s most ambitious watches yet, the Portugieser Perpetual Calendar Tourbillon has two extremely rare complications, namely the perpetual calendar and a tourbillon. The prior means that the date needn’t be adjusted on short months, and the latter is a visual spectacle of watch over-engineering. Please call to pre-order.