Portugieser Constant-Force Tourbillon Edition “150 Years” Platinum / White

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 13.4 mm it is a tall case, and it will catch on a cuff. 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 is hand-wound, so winding it becomes part of the day rather than something the watch does for you. 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.

IW5902-02 is one of 2 executions of the IW5902 base reference. Underneath they are the same watch; what separates this one is a white gloss dial and a platinum case. It was a limited edition. Beyond the time it carries a tourbillon.

IWC manufactured 94805 calibre (94000-calibre family) is a hand-wound movement with a tourbillon escapement. A patented constant force mechanism is integrated into the tourbillon, ensuring a stable amplitude of the balance - visible through 1 second jumps of the tourbillon. After having run for 48 hours, the constant force mechanism is decoupled and the tourbillon will move in regular 1/5th of a second intervals. It furthermore features a day/night indication, double moonphase display and a 96 hour power reserve.

3 other watches in the library run the IWC 94805.

IWC

Big Pilot Constant-Force Tourbillon Le Petit Prince / Red Gold

IW5903-03 · 46 mm

IWC

Portugieser Constant-Force Tourbillon Edition “150 Years” Platinum / Blue

IW5902-03 · 46 mm

IWC

Big Pilot Constant-Force Tourbillon Le Petit Prince / Platinum

IW5903-02 · 46 mm