IWC Portugieser Perpetual Calendar 44 IW503702

Over the last two decades, the Portugieser Perpetual Calendar has established itself as a key pillar of the collection. Originally developed by IWC Schaffhausen’s former Head Watchmaker Kurt Klaus in the 1980s, the perpetual calendar complication has been continuously improved and perfected over the years. The first Portugieser with a perpetual calendar was launched in 2003. The moon phase display was enhanced with a larger reduction gear by taking advantage of the more generous case dimensions, increasing its accuracy from 122 to 577.5 years. Another innovation was the patented Double Moon™ display, which shows the moon phase as seen from the Northern and Southern hemispheres. IWC Schaffhausen has now completely reworked and refined this model and presents four new versions.

The Portugieser Perpetual Calendar 44 (Ref. IW503703) features an 18-carat white gold case, a Horizon Blue dial, and rhodium-plated hands and appliques. It is fitted with a gradient light-blue calfskin strap from Santoni. The Portugieser Perpetual Calendar 44 (Ref. IW503704) has an 18-carat white gold case, a Dune coloured dial, and gold-plated hands, and gold appliques.

It is combined with a black alligator leather strap from Santoni. The Portugieser Perpetual Calendar 44 (Ref. IW503702) boasts a case made of 18-carat Armor Gold®, an Obsidian black dial, gold-plated hands, and gold appliques. Thanks to an improved microstructure, Armor Gold® is considerably harder and more wear- resistant than conventional 5N gold. This model is fitted with a black alligator leather strap from Santoni. The Portugieser Perpetual Calendar 44 (Ref. IW503701) impresses with an 18-carat Armor Gold® case, a Silver Moon dial, gold-plated hands, and gold appliques. This fourth timepiece is fitted with a brown alligator leather strap from Santoni.

COMPLETELY REWORKED CASE CONSTRUCTION WITH DOUBLE-BOX SAPPHIRE CRYSTALS AND NEW DIAL FINISH

The most notable design change is the completely redesigned and refined case construction. The slimmer case ring features a more slender side profile.

In combination with the box-glass sapphire crystals on the front and the back, this new construction makes the watches particularly light and elegant. The box- glass sapphire crystal, milled and polished in a highly complex process, allows for an even better view of the iconic Portugieser design cues, such as the characteristic minute scale. The dial graphics have also been carefully reworked and refined. A particular highlight is the elaborately crafted dials. The key to their extraordinary visual depths is the application of 15 layers of transparent lacquer, which is fine-ground and then polished to a high gloss finish. The subdials displaying the calendar information are milled into both the brass base and the lacquer layer. Finally, the appliques are individually mounted on the dials by hand. Comprising up to 60 individual steps, the production process for the dials is incredibly complex and challenging to master.

All four watches feature IWC’s signature Double Moon™ display. Inspired by nautical instruments, it shows the moon as it can be seen from the Northern and Southern hemispheres. Thanks to a precisely calculated reduction gear, the indication will only deviate from the moon’s actual orbit by one day after 577.5 years.

The watches are powered by the IWC-manufactured 52616 calibre movement, which is assembled from 385 individual parts. The escapement has been improved to offer better protection against magnetic fields. The automatic Pellaton winding system features components made of virtually wear-free zirconium oxide ceramic, while the oscillating mass is made of solid gold. Converting the movements on the wearer’s arm into energy for the mainspring, it reliably builds up a power reserve of 7 days in two barrels.

THE PERPETUAL CALENDAR WAS A MILESTONE FOR IWC SCHAFFHAUSEN

The introduction of the perpetual calendar in 1985 marked the beginning of IWC Schaffhausen’s comprehensive expertise in mechanical calendar complications. Kurt Klaus created a complication that is remarkable in many respects. All its displays are perfectly synchronised with each other and can be easily advanced via the crown. The calendar comprises only 81 parts, all housed in a module that is 1.5 millimetres high. With its ingeniously simple design, the complication perfectly embodies IWC Schaffhausen’s engineering approach to fine watchmaking, characterised by functionality, efficiency, and ease of use. The calendar is mechanically programmed for a cycle of four years. In addition to recognising the different lengths of the months, it automatically inserts a leap day every four years at the end of February. The mechanical program only requires a minor adjustment in centuries divisible by 100 when the leap year is skipped, for example, in 2100 or 2200.