IWC Mark XI Pilot R.A.F Military Issued 6B/346 from 1952

In 1948, the Mark XI watch was jointly developed by International Watch Company (IWC) and Jaeger-LeCoultre (JLC) based on British Ministry of Defense (MoD) specifications. These timepieces prioritized functionality and became classic models. IWC and JLC produced similar-sized watches following MoD standards. JLC stopped production around 1953, while IWC continued until the early 1980s.

The MoD required the watches to be marked with a broad arrow as government property. The example discussed here meets these standards and is engraved with "6B 346 13xx/52," indicating its specific model and production year. The Mark XI featured the reliable manually wound caliber 89, ensuring accuracy for British pilots during missions.

This military watch included key features like fixed spring bars, luminous dial and hands, hacking seconds, and a soft iron cover to protect against magnetism. The one described here was issued to the Royal Air Force (RAF)

To maintain accuracy and comply with changing regulations, these Mark XI watches were routinely serviced. The dials were often relumed, and after 1962, a "T" in a circle was added to indicate the use of tritium luminescent material, similar to other British military-issued timepieces like MilSubs and Omega Seamaster 300s.

Brand: International Watch Co.
Model: Mark XI 
Reference: 6B/346
Year of Manufacture: 1952
Serial Number: 13xx
Material: Steel
Dimensions: 35x46mm
Crystal Material: Plexiglass
Luminous Material: Tritium
Movement Type: Cal.89
Bracelet Width: 18mm
Bracelet: M.O.D issued Nato
Box/Papers: No