IWC Schaffhausen Portuguese Sidérale Scafusia – Grand Complication with Perpetual Calendar, Constant-Force Tourbillon, Sidereal Time, Solar Time, Celestial Chart, Sunrise and Sunset Display

Introduced for the first time in 2011, the Portuguese Sidérale Scafusia is a grand complication timepiece which was created after a decade of research by a team of engineers, watchmakers and scientists of IWC Schaffhausen.

Portuguese Sidérale Scafusia, the most complicated timepiece ever made by IWC combines solar time and sidereal time on a single dial. From the front, this fascinating masterpiece is a classical Portuguese watch, from the reverse side an astronomical instrument.

The patented constant­force tourbillon is the most conspicuous feature. The tiny space on the reverse side accommodates a celestial chart, horizon, geograph­ical coordinates, solar time, sidereal time, sunrise and sunset display as well as a display showing daytime, night­time and twilight. Also not to be forgotten is a com­pletely integrated perpetual calendar behind the display showing the number of the day.

The Portuguese Sidérale Scafusia combines the romanticism of the night sky with science at the cutting edge, while combining complex watchmaking technology with unbelievably simple oper­ation and a craftsman’s love of detail with forward thinking vision. For all its precision and attention to detail, the Portuguese Sidérale Scafusia watch is eminently suitable for everyday use: it is water-resistant to 3 bar and, considering that the mechanism is so delicate, astonishingly impervious to shocks.

The Portuguese Sidérale Scafusia is not made in series production. Every single watch is produced exclusively to order by the customer and is an individual project in itself.

Since the star chart and horizon as well as sunrise and sun­set times have to be calculated and displayed for a precise location specified by the customer, individual mechanical parts have to be custom manufactured, then assembled and adjusted individually. This means that every customer is not only wearing a unique watch on his wrist but also his own personalised constellation of stars, as seen in the night sky from the location of his choice.

With the Portuguese Sidérale Scafusia timepiece, individuality is of the utmost importance. As part of a special service, customers can design their own precious watches within the limits set by IWC’s design philosophy. The range of case and strap materials, together with the choice of five different colours for the dial as well as various colours for the appliqués and straps, results in over 200 possible combinations.

In view of this individuality and the highly demanding design work involved, buyers will have to wait approximately one year for delivery.

Technical details
Model: Portuguese Sidérale Scafusia
REF. IW504101

Dial side displays
24-hour display (sidereal time)
Sidereal time and solar time can be set separately
Power reserve display

Rear side displays
Customized celestial chart and horizon
– Sunrise and sunset display
– Sidereal time and solar time
– Day, night and dusk display under celestial chart
– Perpetual calendar with display showing leap years and number of day

Calibre   94900, Hand-wound Mechanical movement
Frequency: 18,000 A/ h / 2.5 Hz
Jewels: 56
Power reserve : 4 days (96 h)
New balance with 2 adjustment cams and 2 adjustment weights
Breguet spring
2 barrels
Constant-force tourbillon

Material as specified by customer (e.g. platinum or red gold), strap as specified by customer with IWC folding clasp
Glass: sapphire, convex, antireflective coating on both sides
Back: see-through sapphire-glass back
Water-resistance: 3 bar
Diameter: 46 mm
Case height: 17.5 mm

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