This is the first time IWC has produced a watch with hard gold, a special new version of 5N gold. The microstructure of the alloy is modified in a sophisticated manufacturing process. Hard gold is therefore significantly harder and around 5 to 10 times more wear-resistant than conventional 5N gold. As a result, the material is perfectly suited to the large case and the crown of a Big Pilot’s Watch.
The patented constant-force tourbillon is the IWC engineers’ answer to a centuries-old challenge in the field of watchmaking: As the tension in the spring of a mechanical wristwatch slackens over time, less force is transferred to the escapement via the dial train, which in turn decreases the amplitude of the balance. This has a negative impact on the precision of the watch. The patented constant-force mechanism separates the escapement from the direct flow of force from the dial train and with every second re-tensions a balance spring, which serves as temporary energy storage and transfers absolutely even force pulses to the escape wheel. Integrated into a tourbillon, which also eliminates the influence of gravity on the oscillating system, the result is extraordinary precision.
The IWC-manufactured calibre 94805 combines a constant-force tourbillon with a perpetual moon phase display, which takes 577.5 years to require adjustment by one day. The “Petit Prince” stands on the moon. Two barrels store enough power for 96 hours. A display notifies the wearer of the remaining power reserve.