Unveiled at the Salon International de la Haute Horlogerie (SIHH) 2019 in Geneva, the Big Pilot’s Watch Constant-Force Tourbillon Edition “Le Petit Prince” (Ref. IW590302 and IW590303) are the first pilot’s watches from IWC with a constant force tourbillon. It is available with either a hard gold or platinum case, each of which is limited to 10 watches in each material.
The watch comes in two editions: In platinum case with blue dial, rhodium-plated hands and brown calf leather strap (Ref. IW590302) and in 18 carat hard gold case with blue dial, gold-plated hands and brown calf leather strap (Ref. IW590303).
This is the first time IWC has produced a watch with hard gold, a special new version of red 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 red 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.
Power reserve display
Tourbillon with integrated constant-force mechanism
Perpetual moon phase display
IWC-manufactured calibre 94805
Frequency: 18,000 vph / 2.5 Hz
Power reserve: 4 days (96 h)
Case, dial and strap
Ref. IW590302: Platinum case, blue dial, rhodium-plated hands, brown calf leather strap
Ref. IW590303: 18 carat hard gold case, blue dial, gold-plated hands, brown calf leather strap
Crystal Sapphire, arched edge, anti-reflective coating on both sides
Water-resistance 6 bar
Diameter 46.2 mm
Height 13.5 mm
See-through sapphire glass back
Glass secured against displacement by drops in air pressure
Limited to 10 watches