Watch family · Style & purpose
Dirty Dozen Military Watches
Partially verifiedThe informal collectors' name for wristwatches supplied to the British War Office under the 'W.W.W.' (Watch, Wristlet, Waterproof) specification by twelve named Swiss and British manufacturers, sharing a common broad-arrow-marked, plain military dial specification despite differing movements between makers.
Movement & mechanism
- Manual-wind lever movements meeting the W.W.W. specification for accuracy and shock resistance, varying in calibre between the twelve contracted manufacturers
- Common specification dial: black dial, luminous Arabic numerals, railway (24-hour) minute track and a subsidiary seconds dial
- Screw or snap case backs stamped with military issue markings
Identification
- Broad arrow ('pheon') government property mark stamped on the case back
- 'W.W.W.' marking together with a military store reference number on the case back
- Common dial layout across all twelve makers despite differing movement calibres and case suppliers
- Maker name on the dial identifying which of the twelve contracted firms supplied that example
Terminology
- W.W.W. — Watch, Wristlet, Waterproof, the British War Office specification these watches were built to
- Dirty Dozen — the informal, retrospective collectors' name for the twelve contracted manufacturers, not a period term
- Broad arrow — the British government ownership mark stamped on issued equipment
Known variations
- Examples from each of the twelve contracted manufacturers, which differed in movement calibre and case supplier while sharing the specification dial
Pocket-watch ancestry
The W.W.W. specification continues a long British tradition of military timepiece procurement to a written specification that began with pocket watches; the twelve-maker wristwatch contract of 1945 applies the same procurement logic and legibility requirements to the wrist-worn form that had by then become standard general-service issue.
Collecting notes
One of the most actively collected military watch categories; because case backs, dials and movements were sometimes separated or swapped during decades of service and later trading, matching original case, dial and movement configuration to published contract records is central to authentication, and case-back markings are a frequent target of forgery.
Background
British military requirements for a robust and reliable wristwatch necessitated the development of the W.W.W. standard, which stands for watches, wristlet, waterproof. The War Office considered the earlier Army Trade Pattern watches insufficient; the specification was formally approved in 1945, but manufacturers were invited to supply watches to it as early as 1943. These watches are popularly known among collectors as the Dirty Dozen.
Written from the encyclopedia entries listed under Sources; each statement was checked against the cited text.
Defining features
- The specification mandated a high-quality, 15 jewel movement that offered isochronal performance and shock resistance.
- Each watch was required to feature a matte black dial with a subsidiary seconds hand and luminescent markers for legibility.
- Cases were constructed to resist water, dust, and shock, and were fitted with a shatter-resistant perspex plastic crystal.
- The British military broad arrow mark was officially stamped on both the dial and the case back.
Later development
- Delivery of these military watches commenced in 1944, with the majority of units arriving after May 1945.
- One version produced by IWC is noted for serving as the namesake for the Mark X classification.
Photographs





Photographs are illustrative examples of the type, not necessarily the exact object described. Verify details against the source file page.
Sources & references
- Waterproof wristlet watch, Wikipedia (English), retrieved 2026-10-28 (text CC BY-SA 4.0)
- National archive procurement records vary in completeness and are not fully reproduced here.
Where sources disagree, the disagreement is stated rather than resolved silently.