The history and development of the wristwatch is inextricably tethered to the military. While the Great War cemented the appeal and credibility of wristwatches among men, it was the Second World War that financed some of the greatest developments in watchmaking.

As aviation became a critical part of modern warfare – much of WWII, in fact, took place in the skies – wristwatches became essential in managing new technologies and deploying strategies, paving the way for some of the 20^th century’s most admirable and desirable watches.

With the coming of the war, various types of watches created with the pilot in mind came into being, some more impactful than others. The British Royal Air Force was issued with the legendary IWC Mk 11 while across the Atlantic, the U.S. Army Air Forces were equipped with the comparatively prosaic A-11, often referred to as “the watch that won the war.”

However, arguably the most fascinating and highly spec’d variety of pilot’s watches, particularly from a mechanical standpoint, was the chronographs, which enabled pilots to make rapid calculations and conduct precise timing. While most of them went undervalued for many years, they are – pardon the pun – flying high at the moment, not least because they offer a synthesis of purpose and beauty inside and out that is worth preserving.

The Flieger Chronograph

It all began with the Germans, who were said to be the only combatants during the Second World War to be strapped with proper stopwatch capabilities. The chronographs made for the Luftwaffe are no doubt among the most important WWII-era watches, being highly sophisticated both inside and out, and to which the more famous Type 20 owes much of its design.

Hanhart in the Black Forest and Tutima (or UROFA-UFAG as it was known) in Glashütte supplied pilot’s chronographs to the Luftwaffe from 1938 and 1941 respectively. The watches’ defining feature was the flyback function, which was a nascent technical accomplishment that played a crucial role in cockpit functionality. First invented by Longines just a few years prior in 1936, this simple yet efficient mechanism offered a considerable advantage as it allowed pilots to quickly reset and restart their watches for dead reckoning navigation.

Several versions of the watch were made by both companies, but the archetypal variant was the dual-button flyback chronograph that was powered by the Hanhart cal. 41 (1939) or the Tutima cal. 59 (1941). Hanhart also produced a version using the monopusher cal. 40 (1938) without a flyback mechanism. Mechanically speaking, the most apparent difference in a flyback chronograph would be the lack of a tab on the reset hammer which allows the chronograph to be reset while running.  Upon reset, a separate lever disengages the chronograph. Then once the pusher is released, the lever is released, and a spring then pushes the gear train to engage the chronograph seconds once again.

These chronographs were of a classical column-wheel design and notably, were fitted with an Incabloc shock protection for the balance assembly. They differed aesthetically from the Type 20 in their nickel-plated brass cases, knurled bezel with a red marker, cathedral hands as well as the occasional red-coated pusher. The Hanhart chronographs with the cal. 41 in particular had an asymmetric position of its pushers for ease of operation.

Alas, military watches, by their very nature, were used and abused, and these chronographs are rarely found in good condition also due to their case material. Their historical significance, however, is undeniable.

The Type 20

Following the Second World War, as part of reparations to France, Hanhart went on to produce Type 20 watches for the French Air Force under the name Vixa. It was one of at least seven firms who produced these Type 20 chronographs, along with Mathey-Tissot, Airain, Auricoste, Seliva Chronofixe, Dodane, and of course, Breguet whose Type 20s are the most coveted today.

The specifications are conventionally reckoned to include a sub-38mm case with a screw-in back and thickness of not more than 14mm, accuracy of within eight seconds a day, and most importantly, a flyback chronograph with a start-stop function that at the point of issue would work reliably at least 300 times. But beyond that, they varied in terms of counters, hands, bezels, crown sizes and shapes.

Mathey-Tissot, who delivered chronograph wristwatches to the U.S. Army’s Corps of Engineers during the first world war, was subcontracted to produce the Type 20 for Breguet.  It is believed that approximately 2000 Type 20 chronographs were delivered by Breguet in the 1950s. They were equipped with the Valjoux 222. Later versions sold to the civilian market were powered by the 222, 225, 235 and 720.

Notably, the Breguet Type 20s produced for the French Air Force differed from those made for the navy in that it had a soft-iron cage to protect the movement from magnetism. Additionally, they also featured a 30-minute counter while the navy versions had an extra-large, “big eye” 15-minute counter.

As manufacturing costs rose, the French government discontinued its use. However, Breguet began selling these watches to the general public with their name on the dial. In contrast to the original, military-issue versions, the watches are identified by the model name in Roman numerals – Type XX.

It is believed that Breguet produced approximately 2,000 Type XX for the civilian market, out of which, only three were made in yellow gold. In 2018, one particular gold example was sold at Phillips for 200,000 Swiss francs.

RAF Lemania

The most famous military watch on the other side of the English Channel is no doubt the legendary IWC Mark 11 issued to the British Royal Air Force. But there was also an interesting monopusher chronograph developed for issue to the MoD in the late 1940s to 1970s by Lemania.

These chronographs are divided into three series, with the archetypal version being the third series, which had a distinctive asymmetric case designed to protect the crown and pusher. They were issued to both the RAF and the Fleet Arm of the Royal Navy, and thus had familial design codes characteristic of pilot’s watches such as a large black dial with Arabic numerals, luminous hands and markers.

Most notably, inside the watch was the impressively robust column-wheel Lemania 2220, which unlike that preceding cal. 15CHT that powered the earlier series, featured an Incabloc shock protection system for the balance staff. Additionally, these Lemania movements were also unusual in that instead of having a finger mounted on the chronograph seconds wheel to advance the minutes every 60 seconds, it had an oscillating pinion that couples the second wheel of the gear train to the minute recorder wheel when the chronograph is engaged. Having a separate system like this would in theory minimise the load on the gear train as it eliminates that jump. It will also create a continuously sweeping motion instead of the semi-instantaneous minutes found in regular chronographs.

A. Cairelli CP-1 and CP-2

Among some of the most highly prized military chronographs today are the CP-1 and CP-2 (Cronometro da Polsa Type 1 and 2) developed for the Aeronautica Militare Italiana (AMI), or Italian Air Force in the 1960s through the 1970s and sold by Roman retailer A. Cairelli. However, the story of the CP-1/CP-2  chronograph began with an even more remarkable watch – the Type HA-1, an extremely rare, oversized split-seconds chronograph from 1953 made by Universal Geneve.

Measuring 44.5mm wide, the watch is massive even by today’s standards and features a white 24-hour dial with a 16-minute counter for pilots to calculate the hour angle. Crucially, the watch is powered by the Valjoux 55 VBR, the same split-seconds movement in the legendary Rolex ref. 4113. Due to its contemporary dimensions, extraordinary movement and rarity, prices for this are now north of 150,000 Swiss francs.

The HA-1 was replaced by the CP-1 produced by Leonidas and later the CP-2 by Universal Genève, Zenith and once again, Leonidas. The two generations differed in size: the CP-1 was 39mm wide while the CP-2 was 43mm. Both, like the HA-1, were powered by movements originally designed for pocket watches, hence their dimensions. The CP-1 was powered by the Valjoux 22-2 movement with flyback and hacking functions.

The CP-2 was characterised by a distinctively wide, black bezel that is hugely reminiscent of the Heuer Bund chronograph. The Zenith watches were powered by the cal. 146 DP (not a flyback) produced by chronograph specialist, Martel which was the movement maker acquired in the late 1950s. The Leonidas CP-2 was powered by the Valjoux cal. 222, the same movement used in the Breguet Type 20. The Universal Genève version, on the other hand, utilised the cal. 265P, but production is believed to be limited due to cost.

All CP-2s featured a three-part case with screw-down case back, an inner dust cover, a black dial illuminated with tritium, a bi-compax chronograph layout and an outer railroad track. In recent times, the CP-2 watches produced by Zenith have fetched sky-high prices on the vintage market.

Bundeswehr Chronographs

From the early 1960s to the early 1970s, Heuer, which acquired Leonidas in 1964, produced the 1550 SG flyback chronograph for the West German Federal Defense Force, or Bundeswehr. Though it is manifestly designed as a pilot’s watch, it was made to conform to the specifications of other service branches as well.

The most intriguing and also the rarest version is the ref. 1551 SGSZ “Sternzeit Reguliert” chronograph made for the artillery forces. While it looks almost identical to the other Bund watches, the movement is actually regulated for sidereal time — meaning it runs approximately four minutes faster a day. This is because the artillery forces used sidereal time to determine true north. Thus, to avoid mistakes, “Sternzeit Reguliert” was printed on the dial.

Like its predecessor the Leonidas CP-2, the Heuer Bundeswehr is a well-proportioned, contemporary-sized chronograph with a strikingly wide, black-coated rotating bezel and oversized sub-dials. They were powered by the flyback Valjoux 222 and later, 230 movements. One quirk was that the case was constructed such that the movement loads from the front. The bezel and crystal are attached to the inner case with four screws visible on the back.

The watches were fitted with a Bund-style leather cuff strap, which was meant to protect the pilot’s skin against extreme temperatures.

In the 1980s, Sinn was engaged to service these Heuer watches. At the same time, a surplus of these watches were also acquired and refurbished by the brand, which used a Sinn-branded replacement dial and sold it to civilians.

While there are numerous versions of the watch, they vary superficially in terms of logo and markings. The earlier radioactive substance was replaced by tritium, hence the dials were marked with “3H”, an abbreviation for Hydrogen-3, the chemical compound for the luminous material. Some versions of the dial included a small “T” above the six o’clock index to denote the use of tritium.

Today, the Heuer Bundeswehr, with the exception of the “Sternzeit Reguliert” version, can be had for 5,000 to 10,000 Swiss francs, which is still a bargain considering its military provenance, contemporary good looks and the superb flyback movement within.

Porsche Design Chronograph

One of the most iconic yet underrated military watches of the 80s was the Porsche Design Chronograph 1 made by Swiss military-watch supplier, Orfina. The watch was originally designed for sale to the public in 1972 by Porsche before it was adopted by various air forces around the world.

Importantly, the ingenuity of its aesthetic design and movement was a sharp reflection of its time as the quartz crisis prompted many inspiring breakthroughs across the board as a last hurrah. The case was ovoid in shape paired with a bracelet, but the key feature was its uniform, matte black finish. The Porsche Design Chronograph 1 was the world’s first all-black watch achieved with a surface treatment then only used on military aircraft – physical vapor deposition (PVD).

Powering it was the Valjoux 7750 movement, which was eventually replaced by the incredibly robust Lemania 5100 a couple of years later. In contrast to the pioneering automatic chronographs of 1969, these movements were designed with the implications of the crisis in mind and reflected a starkly different approach to engineering in which doing the most with the simplest, cheapest and fewest components was considered a virtue.

Though both were cam-switch chronographs, they were worlds apart in terms of construction. While the Valjoux 7750 relied on an oscillating pinion to couple the fourth wheel of the movement to the chronograph seconds, the Lemania 5100 had a vertical clutch integrated with the fourth wheel, which drives the chronograph seconds wheel above directly.

As a result, the Lemania 5100 had excellent shock resistance in contrast to horizontally coupled movements of the time wherein the chronograph seconds hand was prone to stopping when subject to shocks. Furthermore, the Lemania 5100 had an unusual pillar-type architecture which significantly reduced construction costs as the parts were able to be stamped instead of having the base plate milled to hold all the gears inside. On top of that, parts were made of low-friction, shock-absorbent materials such as nylon and Delrin plastic.

While the civilian versions were equipped with a mix of both Valjoux and Lemania movements, all watches made for the military were equipped with the Lemania 5100. In these versions, the Orfina logo on the dial was replaced by the word “military”, the tachymeter is typically replaced by a 12-hour scale while the central minute counter hand is blacked out with a red tip.

Today, these watches are becoming increasingly collectible, though the military versions are naturally harder to come by in good condition as the PVD coating wears off with heavy usage. But all in, the significance of this watch reaches far beyond its military provenance, along with the fact that it was designed by the genius behind the Porsche 911.