In the 1940s, the German Air Force, or Luftwaffe, commissioned watches for their pilots from manufacturers such as IWC, Laco, Stowa, Wempe, and A. Lange & Söhne.
Produced to the Luftwaffe's specifications, the watches would all have a mechanical movement with centre seconds, and cases measuring 55mm to accommodate the large movements, which were typically used in pocket watches. The watches would all be fitted on an extra-long leather strap so they could be worn over a flight jacket. The oversized crown could be operated with gloves on, and would be able to stop the central seconds for precise time-setting. The movement would be surrounded by an iron core, to protect against magnetism.
These watches became known as the B-Uhr style, abbreviated for Beobachtungs-uhren, or "Observation" watch. The B-Uhr had two dial variations - Type A dials featured a standard outer minute track and large triangle at 12 o'clock, as in this example, while the later Type B dials had an inner hour track and outer minute track.
The watch cases were engraved on the left side "FL23883" to identify the watch as one designed for navigation. On the inside of the case back, it contained further identifying numbers and information: type (Bauart), production number (Werk-Bez.), and order number (Anforderz). As the watches were property of the Luftwaffe, and not of the individual navigators, the pilots had to return their watches after completing their service, thus enhancing their collectability today.
The present watch is a rare example of a B-Uhr model produced by IWC, and features their large calibre 52.
The IWC utilised a different case to those of other manufacturers, as it has an inner, extra anti-magnetic case and spring mounted lugs. Only 1'000 pieces of this model were produced, and this example is in excellent overall condition, benefiting from a recent service from IWC.