November 2021 17 Min Read

What Came After the Dirty Dozen?

By Kwan Ann Tan

The term “military-grade” can bring to mind images of near-indestructible items. From cars to boots, there is a plethora of everyday objects that have been co-opted by the armed forces over the years, leading them evolving into their purest utilitarian form. While the Dirty Dozen might be synonymous with World War II and the British Army, they were only introduced near the end of the war – and, as such, did not see as much action as we might imagine. But the legacy of these watches lived on, with similar designs and forms that had to adhere to strict military specifications manifesting in watches released after World War II.

We previously covered the original Dirty Dozen in some depth, but we wanted to investigate the pieces that this select group of watches spawned. The 1950s and 1960s saw the creation of increasingly specialised timepieces for different branches of the militaries of the world, and classifications such as field, pilots’ and divers’ watches became even more pronounced, with an emphasis on specific needs like accuracy and water resistance. These pieces bridged the gap between World War II and the use of quartz wristwatches in the military, making use of new technologies and designs, becoming sharper and more keenly attuned to the needs of servicemen.

Changing Specifications

While perhaps not as drastically different from the original Watch, Wristlet, and Waterproof, (W.W.W.) guidelines, the specifications had to keep up with the growing technological developments of the time, each mirroring and anticipating the other’s needs.

According to the 1947 Defence Standard (Def Stan) set out by the British Ministry of Defence, the watch essentially had to “be of the luminous wristlet type in a stainless steel or other approved metal waterproof case, and shall be capable of withstanding tropical conditions”. The document goes on to specify in detail the types of dials that were acceptable, in addition to type of material, and down to the exact measurements of the distance between lugs and the case size

The evolution of the general service case and dial, courtesy of Kenneth Gordon and the Horological Journal.

Alex Barter, an expert who ran Sotheby’s watch department in Geneva for over a decade, and the author of The Watch: A Twentieth-Century Style History, notes that some of the most crucial elements that were shared across these different types of military watches included a legible dial and anti-magnetic properties.

Oren Hartov, watch editor at Gear Patrol and a reserve paratrooper in the IDF (Israel Defense Force), explains that – in strictly practical terms for the wearer – during service “you need something waterproof. You need something mudproof. You need something you can beat the crap out of.” In these terms, it seems that fundamentally this need hasn’t changed much over the years, as we see the same concerns being addressed in the defence and/or military specifications for watches from this period.

Dial and Case

As the most important part of the watch, the dial was given a particular focus in the Defence Standards laid out by the British Ministry of Defence. Standards across the board for most countries specified that a matte-black base should be used with white numerals. This was to ensure legibility, especially at night.

There were also specifications laid out for the luminous material used on the dials, targeted at horizontal batons and strategically placed luminous dots throughout, but a tricky balance had to be struck between the need for legibility and the need for stealth, especially in the dark. The watch could not be too luminous, otherwise the wearer was in danger of being spotted by enemies.

The case shape evolved across this period as well, with the bezel expanding and becoming more solid – compare, for instance, the difference between the relatively slim shape of a Smiths W10 and the protective, tonneau-shaped case of a Hamilton W10.


There was a wide range of movements used across this period, especially because of the specialisation into different types of watches. Pilots required chronographs, while divers needed timer bezels that they could use even while underwater. Shock protection was crucial for all watches, and Incabloc protection became a standard requirement.

For field and general service watches, the “hacking seconds” function was necessary for the agreed-upon centre seconds hand. This meant that the crown could be pulled out to stop the second hand, allowing it to be synchronised to a reference source. This moment in particular has been glorified in many film scenes where, before embarking upon a big or important mission, the men are ordered to “synchronise watches” – and, of course, in crucial, real-life operations, this could quite literally mean the difference between life and death.

The technology behind the Incabloc shock absorber, courtesy of Revolution Watch.

There were also changes made with reference to the pushers on a watch, such as in the British Def Stan of 1969, where two were allowed, while previously only single pushers had been sanctioned.


Military specifications mostly left the choice of glass up to the makers, only noting that an “approved unbreakable type” should be used. Typically, plexiglass or acrylic crystals were used on military watches. Both materials provided an advantage over sapphire as they would crack rather than shatter, making them more durable. Mineral glass was also an option, which was significantly more affordable than sapphire crystal.

Performance Testing

Rigorous performance testing was conducted on all these watches, including for different tropical climates, in consideration of the travel that these watches were likely to have to undergo when soldiers were deployed overseas. The general service watches were tested at temperatures from 32°C, even going up to 49°C and down to 12°C, for both mean variation and mean daily rate, in various positions.

Accuracy was a main focus, as in 1947, the British Def Stan specified that the watch could only have an error of +/- 15 seconds, a number that was narrowed down between 1951 to 1969 to an allowable difference of +20/-10 seconds. With the advent of quartz watches in the 1981 Def Stan, the new general service wristwatches now had to be accurate to +/- 0.5 seconds, a tighter and tighter margin of error.

Notably, these demands on accuracy were for the general service watches – navigators’ watches had to be twice as accurate and were held to stricter standards.


Anti-magnetism was a strict requirement for watches during this period, as the influence of a magnetic field on the movement would cause it to lose accuracy, as metal parts in a watch could become magnetised.

The watches were required to undergo testing that placed them in magnetic fields of up to 150 oersted. Kenneth Gordon notes in his article for the Horological Journal (“Zulu Time – The British General Service Wristwatch”) that these initial tests were conducted by the British Royal Aircraft Establishment in 1946 and tested against “the maximum field strength likely to be encountered in aircraft and was based on the known leakage amount of a powerful magnetron used in airborne radar equipment”.

The “soft iron cage” protecting the watch’s movements from becoming magnetised, courtesy of Sinn.

The concept of anti-magnetic watches had been around for some time, and came to a head with the IWC Mark XI, a pilots’ watch. Dr David Seyffer, the museum curator of IWC, says, “The idea of shielding the movement via a soft iron cage against the magnetic field was a smart move. IWC had been making anti-magnetic movements since 1888, so they had plenty of experience with this. However, the idea that was introduced with the Mark XI was completely new and changed current paradigms. It was no longer the movement that had to be anti-magnetic; it was the construction of the case that made it anti-magnetic. An advantage for the Royal Air Force was that inside was a ‘normal’ high-quality and precise movement without any anti-magnetic alloys or something complicated from a material point of view.”


The “General Service” requirements that were written for wristwatches aimed to set out the guidelines all manufactures had to abide by in order to have their watches bought by any of the armed forces. This would multiply into many different types of specifications as the technology progressed and the needs of the service men and women changed. The field watch is one of the prototypical examples of a military watch as laid out in these guidelines and one that many would instantly recognise as a military-style timepiece.

In exploring the direct successors to the Dirty Dozen, we find that traditionally the British military stuck to using Swiss makers such as IWC, Jaeger LeCoultre, or Lemania – all found in the Dirty Dozen line-up from the late 1940s. The Smiths W10 was one of the last watches used by the British military that was manufactured entirely in the UK to reduce costs by using locally made movements and in an attempt to revive the flagging British watchmaking industry.

The caseback and movement of the Smiths W10, courtesy of Sean Song.

First issued in 1967, the movement used for the W10 was the Smiths 60466E, based on the 27.CS. The movement could specifically allow for a “hacking seconds” function. The Smiths W10 were mostly used as field watches, but there was a 6B designation that was created for the RAF. In general, the styling of the Smiths W10 is reminiscent of the original Dirty Dozen – we can clearly see that, in terms of design, military requirements largely stayed the same even during this period, focusing on practicality and utility.

After the Smiths W10 came the Hamilton, with the same W10 designation, produced between 1973 and 1976. The Hamilton W10 was produced during a time when the military was under significant financial pressure, before their production run was cut short and the contract was passed on to CWC. Jonathan Hughes, a collector and researcher at CWC Addict, notes that the early, manual-wound CWC watches were extremely similar to the Hamilton watches as they were produced in the Hamilton factories themselves.

In the United States, we see that watches have developed very similarly, with the military making use of brands such as Bulova, Benrus, and Hamilton. In particular, the Benrus DTU-2A/P, a piece that was made according to the updated 1962 MIL-W-3818A specification, held up the standard for many future field watches.

Ultimately, there were significant revisions and changes to the specifications for general service watches in this period, both to keep up with the other types of military technology that was being produced and to reflect the new discoveries within the watchmaking industry itself.


The 1950s and 1960s were something of a Renaissance for divers’ watches. Many of these pieces are still celebrated today because of the tests they would have been put through by the many navies around the world at this time.

In terms of diving, Hartov remarks, “Diving was in its infancy during World War II. After the war, especially because of people like Jacques Cousteau, diving became more widespread – almost commercialised – and it was still being developed for the military. Because of the advent of diving, both recreational and commercial, you start to see a lot more specialised watches in the post-war era, especially where divers’ watches were concerned.”

Jacques Cousteau testing an early Rolex Submariner around 1942-1943, courtesy of Perezcope.

The most crucial elements of a divers’ watch included a non-corroding case, a rotating bezel, a clear dial, a robust movement, and a durable strap. The watch needed to be able to withstand the underwater pressure, but also had to be relatively resistant to physical and seawater damage.

Two instantly recognisable examples, the Rolex Submariner and the Omega Seamaster, were used as diving watches by the British military. The Rolex Submariner was employed by both the British Special Air Service (SAS) and the Special Boat Service (SBS) between 1957 to 1967, taking around 1,200 pieces of the Ref. 5513, the Ref. 5517, and the double-stamped 5513/5517. Meanwhile, the Omega Seamaster 300M was used between 1967 to 1971, modified for military use, with fixed spring bars and the engraving on the caseback.

The Omega Seamaster 300M, courtesy of Sean Song.

In addition to the divers’ watches used by the British forces, other examples continued to grow and flourish, truly marking a separate area of specialised military watches. Famously, the Panerai Radiomir was used during World War II by Italian frogmen divers, who were notorious for their stealthy missions under the waves. In 1950, the Luminor was introduced, improving upon the Radiomir model with several different versions, including the original Luminor, Luminor Marina Militare, and Mare Nostrum. Made for the post-war Italian navy, they featured reinforced wire-lugs and no longer had a screw-down case. Perhaps more importantly, for the wearer, they were distinguished by the luminous paint that was no longer radioactive.

Meanwhile, the Blancpain Fifty Fathoms was brought to life in 1953. Powered by a self-winding movement, the piece introduced several features that Blancpain was able to patent, such as an O-ring bezel in the crown and a lockable bezel, so that the diver could see how much time had elapsed. The watch was commissioned for official military use by Bob Maloubier, head of the “Frogmen” unit in the French army, and essentially set the standard for diving watches to come.

The Fifty Fathoms alongside ...
... the Tornek-Rayville TR-900, with noticeable similarities.

The 1963 Tornek-Rayville watches used by the US military were essentially copies of the Blancpain Fifty Fathoms during this period, as they rigorously tested several watches, including the Rolex Submariner, using their tests to inform the specifications for the TR-900. The Fifty Fathoms clearly won out, but their adoption by the US Navy involved a complicated history where a New York City entrepreneur, Allen V. Tornek, convinced Blancpain to allow them to present the Fifty Fathoms watch with “Tornek-Rayville” on the dial instead, disguising the watch and giving them the chance to sneak past the 1933 “Buy American Act” that was still in effect. Very few of these now exist, as they were rumoured to have been destroyed because of the radioactive material they held.

A Rolex Submariner 5513/5517 accompanied by a Royal Navy Divers’ Log and knife, courtesy of Phillips.

The Tudor Submariner was also in use by both French (from 1956 onwards), U.S. forces (between 1964 and 1966) and even the South African Navy in the 1970s. The watch was improved upon through experiments with the French Navy.


For pilots and navigators, the most crucial aspect of a timekeeping device was its accuracy. The difference of a few seconds, after all, could mean the loss of precious litres of fuel, or getting lost because the distance travelled could not be calculated accurately. With huge advancements being made in aerospace at this time, there was an increased specialisation of functions, mostly relating to accuracy.

A row of Royal Air Force planes during the Cold War, courtesy of the Daily Mail.

For example, under the general umbrella of pilots’ watches, there were also navigator watches like the JLC and IWC Mark XI’s. In terms of the differences between navigators’ and pilots’ watches, Dr. Seyffer notes: “The navigation and therefore finding the target or the home airbase depended on the watch. In case of the IWC Mark XI, that means the navigator of a Vickers Valiant, Handley Page H.P. 80 Victor, or a Avro Vulcan had to find accurately his target by astro-navigation and his IWC Mark XI flying with some 400 knots in low-level flight in around 300 feet. The skills of the navigator and the precision made that possible.”

In a way, form followed function in this instance, as Hartov considers that new technology, such as rotary aircraft, led to the creation of helicopter pilots’ watches. This is a concept that seems rather strange now, but speaks to the initial conception of this technology as being something separate from other types of aircraft.

In practice, Khurram Khan, Thomas Koenig, and Greg Steer maintain in their article “Man is (Still) Not Lost” in the Horological Journal that “the Mark XI was the most precise watch on duty at that period and therefore, in the beginning, was issued only to navigators on active flying duty and to aircraft captains, while pilots got issued the old WWII 6B/159 or 6B/234 watches or later on the 6B/542 General Service Wristwatch.” This might come as a surprise, since we now tend to think of all these watches as pilots’ watches, since the idea of a navigator might be unfamiliar to a generation that has grown up with commercial flights.

Up close with the IWC Mark XI 6B/346, courtesy of Shuck the Oyster.

The British Armed Forces made use of both the Jaeger-LeCoultre Mark XI RAF Navigators 6B/34 and the IWC Mark XI, with the latter in use up until 1981. For pilots, there were monopusher chronographs from the likes of Lemania, Breitling, and Rodania, as well as an Omega 6B/542 which was an RAF pilots' watch used back in 1953.

A recurring theme that we continue to see within this period is the repackaging of older watches – perhaps leaning towards tradition – alongside more innovative movements.

The period between 1950 and 1956 also saw three separate production runs for the Waltham A-17 for use in the Korean War by pilots in the U.S. military, a modified version of the Waltham A-11 that saw action in World War II. Other pieces made by Elgin and Bulova were also made according to this specification.

The combination of repackaging wartime watches alongside the adoption of newer movements was particularly true for the German and Italian Flieger and B-Uhren watches (pilots’ and navigators’, respectively) as some were reissued versions of wartime Flieger chronographs. The Flieger, or “flyback” function, for instance, was a required specification that stopped, started, and reset the chronograph through the lower button. The 1950s and 1960s saw the introduction of the Hanhart 417 ES, famously associated with Steve McQueen, in addition to pieces like the Heuer-Leonidas Bundeswehr which was supplied to both German and Italian forces, and the Junghans J88.

A Type XX Breguet Flieger watch, courtesy of Phillips.

The French Ministry of Defence had a similar specification for their Type 20 watches, which were, in turn, based on the German Flieger watches. Of these, Breguet stands out not only for its horological significance, but because it was among the first brands to supply military chronographs in 1950 alongside makers like Vixa, and later on, Dodane, and Auricoste.

The Transition to Quartz

Given that quartz was introduced to the world in 1969, which kickstarted the temporary meltdown of the Swiss watchmaking world, it appears that the military was rather slow on the uptake with regards to this technology, with the first quartz watches being introduced to the British military in 1980 with the CWC models.

Ray Mellor, the founder of CWC (fourth from right), when he served in the British Merchant Marines during World War II, courtesy of CWC.

On this transition, Hughes says, “It took several years for quartz to truly be adopted, which didn’t happen until the mid-to-late 1970s.” For the military to seriously consider using it, he adds, the watches had to be “reliable and, in terms of contracts, had to be [driven] down to the lowest unit cost. So, it took some time before quartz watches were as cheap and reliable as the military needed them to be.”

Ultimately, Gordon notes in his paper: “Each of the three Services continued to require specialised timepieces for certain uses in the 1950s and 1960s, but increasingly the development and publication for specifications devolved away from each of the Services to the broader umbrella of the Ministry of Defence.”

With the improvement of accuracy in timekeeping as well as corresponding advances in technology for airplanes and submarines, watches were no longer the only machines that soldiers had to rely on.

The Connection Between Military and Civilian Watches

While we might assume that military watches were the ones that eventually made the transition into civilian watches, the lines aren’t as clear cut. Barter observes that there was “cross-fertilisation” between both areas during the 1950s, given that some military watches made use of movements that were already being used by civilian pieces, while models made with the general public in mind were eventually co-opted for military use. In many cases, the only difference between a military and civilian version of a watch was the lack of a caseback engraving.

Take for example, the surprisingly robust IWC calibre 89, which had previously been used in dress watches and which powered their military timekeepers. Pieces such as the Rolex Submariner, the Omega Seamaster, or the Fifty Fathoms were also popular divers’ watches before they were commissioned for army use.

The IWC calibre 89 found within a dress watch and within many military-commissioned watches of the period - an incredibly versatile and reliable movement, courtesy of Watch Club.

Yet, on the other hand, you saw watches such as the Tudor “Snowflake” Submariner (Ref. 7016/7021) being sold in jewellers’ stores between 1966 and 1968 with modified ETA movements. In the case of the IWC Mark XI, Dr. Seyffer notes that thanks to a restructuring of the British forces and a shift in focus away from the RAF, “planned sales of more IWC Mark XIs to the RAF was stopped in the 1960s. Some 500 watches were sold by IWC as civilian Mark XI or Ref. 2612. They do not have the engravings of the Royal Air Force – the broad arrow and the specifications – [but] were sold without being advertised to watch collectors from the mid-1970s until the early 1980s. Then IWC decided to launch a completely new and civilian-only ‘Pilots’ family.”

The dial of a Tudor “Snowflake” Submariner, courtesy of Chronoshop.

To this day, brands continue to make modern homages to some of their battlefield-tested pieces of the past, and it’s clear that these watches still captivate the modern imagination.

Parting Thoughts

The short answer to “What came after the Dirty Dozen?” can be summed up rather pithily: a lot. The longer answer is that the path set out by the Dirty Dozen diverged into many branches, each affected by the new technologies that were being developed during this period.

Exploring and listing all of the watches that occupied this period would be a herculean task, which speaks to the constant improvement of watches in addition to the changing needs and specifications set out by respective militaries. Furthermore, the influence of commercial markets and other civilian watches that were being developed during this period to meet specific needs, such as diving, created a conversation between the two worlds that still exists today.

An advertisement for the 1957 Rolex Submariner with a distinctly leisurely flavour, courtesy of Jake’s Rolex World.

Moving into the present day, we see that digital watches rather unsurprisingly dominate the scene, with the G-Shock 2000 being the most popular for servicemen thanks to its hardiness and ease of use. The romance of vintage watches may perhaps have been lost for the military in favour of increasingly practical solutions but, for the collector, they still represent an era of expansion and exploration, of a time when heroic exploits relied on the accuracy (and luck!) of one’s watch.

We would like to thank Alex Barter, Oren Hartov, Jonathan Hughes, and Dr. David Seyffer at IWC for taking the time to speak with us and share their insights on these military watches. The research papers published by Kenneth Gordon, Khurram Khan, Thomas Koenig, and Greg Steer were also invaluable resources for this article.

Slideshow credits (in order of appearance) go to HSTE on Watchpro, Bulang & Sons, and Adventures in Amateur Watch Fettling.