The Pellaton winding system
In 1950 IWC's technical director Albert Pellaton patented a novel bidirectional automatic winding system. Most automatic watches use a reversing-wheel system where the rotor drives wheels that wind the mainspring in either rotation direction. Pellaton's system uses a cam attached to the rotor that drives two pawls alternately as the rotor spins, each pawl pulling on the same ratchet wheel from a different angle. The result is highly efficient bidirectional winding with very few moving parts; the system is so distinctive that it has been a Schaffhausen signature for 75 years.
The 7-day power reserve
The 51111 and related calibers use a single oversized mainspring barrel (compared to the more common dual-barrel approach for long reserves) to deliver 7 days / 168 hours of running. A power-reserve indicator on the dial shows the remaining wind, allowing the user to see when to wear the watch versus letting it run down. This was, at launch, one of the longest single-barrel reserves in the industry; modern long-reserve calibers from other brands have caught up but typically use multiple barrels.
In the Big Pilot 5009
The most famous use of the 51111 is the IWC Big Pilot ref. 5002 / 5009, the 46 mm Pilot's Watch that defines the modern oversized pilot category. Pellaton winding, 7-day reserve, large onion crown, simple matte black dial with applied numerals and large luminous hands. The Big Pilot has been in continuous production since 2002 with relatively minor refinements; the current Big Pilot 5010 uses an updated movement (Cal. 52110) but the architecture and Pellaton winding lineage are preserved. The 51111 also powers the Portugieser Automatic 7 Days (refs 5001, 5007, etc.) in 42 mm cases.
Family variants
The 50000 / 51000 family expanded over time:
- Cal. 51011: with chronograph module (Big Pilot Top Gun Chronograph)
- Cal. 51110 / 51111: standard 7-day automatic
- Cal. 51614: perpetual calendar variant
- Cal. 52000 family (Cal. 52010, 52110, 52615): modernised successors with twin-barrel architecture for refined power delivery, in current production for the latest Big Pilot and Portugieser references
The 52000-family is the modern continuation of the 50000 lineage; both share the Pellaton winding identity.
Where it sits
A used Big Pilot 5009 with the 51111 trades on the secondary market at USD 7,500-12,000; current new Big Pilot 5010 watches retail at USD 14,500. The 51111 is no longer in current new production but is fully supported by IWC service. For collectors, the 51111-equipped Big Pilot represents the pure 2002-2010 generation of IWC's most iconic modern reference, with the Pellaton winding system in its classic single-barrel implementation. The Pellaton system itself remains active in the 52000-family successors.
