Ten years in the making and $750,000 in the pocket, this is IWC’s stunning / outrageous /incredible / .. Portuguese Siderale Scafusia Tourbillon.
Available only via custom order, each model will be unique: the star chart on the rear is modelled on the 500-1000 stars visible from the owner’s chosen location.
This is a manually wound piece – you can read more of the technical details below – and ships with a manual-wind capable box to ensure you’re always ready to roll with this bad boy fully wound.
Not that being fully wound is essential to the watch’s accuracy – the watch has a ‘constant force’ tourbillon to ensure power is evenly spread over the bulk of its 96-hour reserve.
The broader movement – an IWC Calibre 94900 – has over 500 parts!
Given the custom nature of this piece, around 200 possible combinations of case type, strap, colours etc are available.
Although, for $750K I’m sure IWC would be willing to ‘talk’ should require something off the menu.
Here’s the press release:
[Press Release] The Portuguese Sidérale Scafusia is the first watch from IWC to feature a patented constant-force tourbillon together with many other complications and individually calculated astronomical displays. Every watch is made on special request and will be unmistakably unique.
Movement is the Swiss hand-wind IWC in-house caliber 94900 with 56 jewels, 18,000 vph and a power reserve of 96 hours. The balance features two adjustment cams and two adjustment weights, a Breguet spring, twin barrels, and constant power tourbillon.
The design of the dial is in the same characteristic style as that of the entire IWC Portuguese watch family. Apart from standard time (or solar time), it also has a display at “12 o’clock” showing sidereal time (or star time), which is vital to astronomers. The newly developed constant-force tourbillon, which combines a tourbillon with a constant-force mechanism, guarantees a regular and precise rate for a period of at least 48 hours. The 90-hour scale of the power reserve display at “4.30” underscores the enormous power generated by the two barrels.
On the rear side of the watch, the night sky disc reveals the full glory of the star-studded heavens. A location chosen by the customer provides the basis of the calculations for the celestial chart and the astronomical displays. Realistically, it is possible to show around 500 to 1,000 stars. The sky disc rotates in a clockwise or anticlockwise direction, depending on whether the chosen geographic location is in the northern or southern hemisphere. The horizon, identifiable as a yellow ellipse, shows the movements of the stars and the section of the sky currently visible in the real night sky above the chosen coordinates.
These coordinates indicate the precise location for which the planisphere has been calculated. The red circle projects the apparent orbit of the Sun in the course of a year on the celestial sphere (ecliptic). The dashed grey circle indicates the celestial equator that separates the northern and southern hemispheres. The red arrow with the dot shows solar time on the outer ring of the 24-hour display while the yellow arrow with the star shows sidereal time, likewise on the inner ring. The two red triangle hands at the edge show the current sunrise and sunset times at the chosen location. The perpetual calendar displays the current date as the number of the day of the year (absolute day). The 1st of January, then, is day 1, the 31st of December day 365, or 366 in a leap year.
As part of its special service, IWC Schaffhausen enables customers to personalize the Portuguese Sidérale Scafusia wristwatch with countless different combinations of features.
Taken together, the choice of materials for the case, the five different colours for the dial, the various colours for the appliqués and straps and the material used for the straps, result in over 200 different design options. IWC is only too pleased to honour special requests in the interests of exclusivity.
The case is made of precious metals such as platinum, 18kt white or rose gold, and measures 46mm x 17.5mm. The crystal is an AR-coated sapphire and it is water resistant to 30 meters. Straps are manufactured from the finest alligator leather or equus-hide.
The Portuguese Sidérale Scafusia is personally presented to its new owner in a top-quality watch case. It contains a removable casket, covered in alligator leather, in which the watch can be safely stored. Integrated into the case is an automatic winder, which was developed especially for this watch with IWC’s engineers. It winds the watch independently once a day via the crown.
The large celestial chart on the inside of the watch case lid is, like the watch’s own celestial chart, individually calculated.
Portuguese Sidérale Scafusia Watch Ref. 5041
Mechanical movement, new balance with two adjustment cams and two adjustment weights, Breguet spring, two barrels, constant power tourbillon. 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
Frequency 18,000 A/ h / 2.5 Hz
Power reserve 4 days (96 h)
Materials Case 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-resistant 3 bar
Diameter 46 mm
Height 17.5 mm