Portugieser Sidérale Scafusia

In Context

At 46 mm it is a large watch — well above this catalogue’s 40 mm median, and enough to dominate a narrow wrist. At 17.5 mm it is very tall, and sits high off the wrist. The case back is open, so the movement is visible without taking the watch apart, and the sapphire crystal will resist everything short of deliberate abuse. Rated to 30 m, it is protected against rain and splashes and nothing beyond that.

The movement winds itself from the motion of your wrist. 96 hours of reserve puts it well past a weekend — several days off the wrist and it is still going. At 18,000 vph the seconds hand advances 5 times a second, the slower and more audible rate of an older design.

IW5041-01 stands on its own in this catalogue — no other reference here shares its base number. It pairs a grey dial with a platinum case.

The imposing constant-force tourbillon gives the viewer a fascinating inside view of the delicately balanced mechanism. The tourbillon’s cage and upper section are made of titanium. The rhodium-plated escape-wheel and nickel-silver stop-wheel bridge are painstakingly hand-chamfered. The brushed bottom plate is inlaid with the “Probus Scafusia” stamp – “Good, solid craftsmanship from Schaffhausen” – IWC’s official seal of quality first used in 1903. The retaining plate and power reserve plate are sandblasted and rhodium-plated. The plate for the astronomical module is likewise made of blasted, rhodium-plated nickel silver. It holds all the displays and technical parts such as wheels, levers and bridges that are needed on the rear side.