IWC Schaffhausen – Portugieser Perpetual Calendar with a Double Moon (Ref. 503401 & IW503404) and Portugieser Perpetual Calendar with a Single Moon (Ref. IW503301 & IW503302)

IWC Schaffhausen Introduces two new versions of the Portugieser Perpetual Calendar: one with a double moon and one with a single moon, and their nine functions are powered by in-house movements from the IWC 52000-calibre family. Thanks to a number of modest design changes, the Reference 5034 now more closely resembles the Portugieser family and conveys an altogether more discreet and elegant impression.

In the revamped models, the Portugieser Perpetual Calendar with a double moon (Ref. 5034) and the Portugieser Perpetual Calendar with a single moon (Ref. 5033), the moon phase display is not only the visual centrepiece of the dial. It is also the technical highlight of a premium timepiece rich in watchmaking tour de force.

Portugieser Perpetual Calendar with a double moon (Ref. 5034)

The perpetual moon phase display is one of the Schaffhausen manufacturer’s most spectacular in-house designs, primarily for a level of precision unique in a mechanical wristwatch. It takes the moon 29 days, 12 hours, 44 minutes and 3 seconds to orbit the earth. Generations of watchmakers have been frustrated by the attempt to translate these figures into a moon phase display using only the size and number of wheels in a train.

Conventional moon phase displays in mechanical wristwatches need to be corrected at relatively short intervals. Kurt Klaus, the master watchmaker at IWC who designed the company’s first perpetual calendar, succeeded in the mid-1980s in reducing the deviation of the mini-moon of the display compared to the moon’s actual orbit to just 1 day in 122 years.

It was a masterstroke surpassed only in 2003 with the introduction of the large 5000 calibre. Thanks to its considerable size, the calibre’s larger moon phase wheels have a higher transmission ratio. As a result, the display will need to be corrected by 1 day only after 577.5 years.

In the Portugieser Perpetual Calendar with the double moon (Ref. 5034), the moon phase and its mirror image show the state of the moon in both the northern and southern hemispheres. This ingenious achievement was also the work of IWC’s engineers, who had set themselves the goal of giving owners south of the equator a view of the moon phase that corresponds to the way they see it.

Portugieser Perpetual Calendar with a double moon (Ref. 5034)

For the first time, the model no longer features the countdown display that shows the number of days remaining until the next full moon. Instead, the watch designers have transformed the subdial with the double moon display into a star-studded night sky the same colour as the large dial, so  that  the  moon  and  stars  appear  to  hover  in  infinite space.

A further new feature of the design is the introduction of the railway-track-style chapter ring typical of the Portugieser, which puts the model closer in appearance to the classic original. The dial appears more balanced and elegant because the subdials for the date and week are also the same colour. No visible changes have been made to the model with a single moon (Ref. 5033) with the exception of several minimal design modifications. However, the new arched-edge front glass reduces the optical height of the case.

Portugieser Perpetual Calendar with a single moon (Ref. 5033)

The perpetual calendar shows not only the lunar cycles but also the seconds, minutes, hours, date, day, month and year in four digits. Mechanically programmed, the calendar takes into account the different lengths of the months and even the leap years.

Nevertheless, every 100 years (2100, 2200 etc.) a leap day that would normally be due is omitted, which means that a watchmaker will have to advance the calendar on 1 March. Another intervention will be necessary in 2300 in order to replace the current century slide, which bears the numbers 20, 21 and 22, with a new one for the years 2200 to 2499.

Portugieser Perpetual Calendar with a single moon (Ref. 5033)

Both models feature in-house movements from the new IWC 52000-calibre family. Two barrels supply the power needed to provide 7 days’ running time and to drive nine functions and displays. The bidirectional Pellaton winding mechanism with its new ceramic pawls is extremely efficient.

A glance through the see-through sapphire-glass back reveals the sophisticated design of the IWC-manufactured 52610 (Ref. 5033) and 52615 (Ref. 5034) movements. The engraved rotor is made of solid 18-carat red gold.

Thanks to the slimmer proportions and perforated bridges, the technological features inside the watch are now easier to distinguish. Clearly visible are the elements new to the calibre family such as the twin barrels, the new ceramic components and the blued screws. For many watch lovers, the latter are an indispensable adornment of an in-house movement, as indeed are the various decorations on the bridges.

The Portugieser Perpetual Calendar with a single moon is available in two versions: in an 18-carat white gold case (Ref. IW503301) with a slate-coloured dial and in an 18-carat red gold case (Ref. IW503302) with a silver-plated dial and a red gold-plated moon against a midnight blue background.

Portugieser Perpetual Calendar with a single moon (Ref. 5033)

The Portugieser Perpetual Calendar with a double moon is likewise available in an 18-carat white gold case (Ref. IW503401) but with a midnight blue dial.

The 18-carat red gold model (Ref. IW503404) with moon phase displays for the northern and southern hemispheres is fitted with a slate-coloured dial. Both watches are fitted with ergonomically optimized strap horns and luxurious Santoni alligator leather straps.

Technical details

Model: IWC Portugieser Perpetual Calendar (Double Moon)
Ref. IW503401 ∙ IW503404

Functions
Power reserve display
Perpetual calendar with displays for the date, day, month, year in four digits and perpetual moon phase for the northern and southern hemispheres
Small hacking seconds

Movement
IWC-manufactured calibre 52615 Mechanical movement
Frequency: 28,800 A/h / 4 Hz
Jewels: 54
Power reserve: 7 days (168 h)
Winding: automatic
Glucydur® beryllium alloy indexless balance with high-precision adjustment screws on balance rim
Breguet spring
Rotor made of 18-carat red gold

Case, dial and strap

• Ref. IW503401: case in 18-carat white gold, midnight blue dial, black alligator leather strap by Santoni, folding clasp in 18-carat white gold
• Ref. IW503404: case in 18-carat red gold, slate-coloured dial, black alligator leather strap by Santoni, folding clasp in 18-carat red gold

Glass: sapphire, arched edge, antireflective coating on both sides
See-through sapphire-glass back
Water-resistant: 3 bar
Diameter: 44.2 mm
Case height: 15.3 mm

Model: IWC Portugieser Perpetual Calendar (Single Moon)
Ref. IW503301 ∙ IW503302

Movement
IWC-manufactured calibre 52610 Mechanical movement
Frequency: 28,800 A/h / 4 Hz
Jewels: 54
Power reserve: 7 days (168 h)
Winding: automatic
Glucydur® beryllium alloy indexless balance with high-precision adjustment screws on balance rim
Breguet spring
Rotor made of 18-carat red gold

Functions
Power reserve display
Perpetual calendar with displays for the date, day, month, year in four digits and perpetual moon phase
Small hacking seconds

Case, dial and strap

• Ref. IW503301: case in 18-carat white gold, slate-coloured dial, black alligator leather strap by Santoni, folding clasp in 18-carat white gold
• Ref. IW503302: case in 18-carat red gold, silver-plated dial, dark brown alligator leather strap by Santoni, folding clasp in 18-carat red gold

Glass: sapphire, arched edge, antireflective coating on both sides
See-through sapphire-glass back
Water-resistant: 3 bar
Diameter: 44.2 mm
Case height: 15.3 mm

• Know more about IWC Schaffhausen watch brand and its history.

• Discover more IWC SCHAFFHAUSEN watches (from 2011 to 2022).

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