The History of the Zenith El Primero, The Glorious High-Frequency Automatic Chronograph That Almost Died

In our series on historically significant calibres, the best way to honour the El Primero calibre is by highlighting its qualities, functional characteristics, and pivotal role in shaping the watchmaking industry. While the tale of its salvation in 1976, along with that of Zenith as a company, by a courageous man defying the ill will of American owners is fascinating, the El Primero’s legendary status is primarily due to the use of advanced technology available at the time of its creation, excellent engineering and movement design, and a modern, industrial approach to production. 

Still, had it not been for Charles Vermot, a Zenith workshop manager, who disobeyed orders to sell the metal presses and tools for manufacturing the El Primero as scrap and instead hid the necessary drawings and tools, watchmaking history would be missing some thrilling episodes. We will return to Vermot’s story shortly, but first, let us revisit how the El Primero came to be.

Episode I – The Years Before Its Birth

Let’s not be original and start the history of El Primero in 1962, when Zenith management started to plan the company’s upcoming 100th anniversary in 1965, and what best way to celebrate if not to present a new, innovative calibre, a self-winding chronograph movement – something strangely enough the world was still missing in the 1960s – and be the first to make one? Zenith’s president of the time, Jean-Pierre de Montmollin, approved the idea and in 1963, the research and development phase began in the workshops at Les Ponts-de-Martel, with Raoul Pellaton leading the teams – the same Raoul Pellaton, who in 1956 replaced Raoul Perret, president of the Martel Watch Company, and came onboard Zenith in 1959 when it bought the Martel Watch Company and effectively all of its patents, with the 100% acquisition completed by 1966. Martel (founded in 1911 by Georges Pellaton-Steudler) was a long-time supplier of quality chronograph movements to Universal Genève from as early as 1918 and to Zenith. The three enjoyed cooperation for decades, which is worth a separate study. (For fun, look for Zenith branded calibre 122 and compare it to the Universal Genève UG281 family while first getting acquainted with the Martel movement 1226/1226 H).

Interestingly, by the late 1950s, Universal began shifting its focus away from chronographs due to the growing international demand for automatic watches, aligning with a global trend. This change left Martel Watch in a difficult position, as Universal had been a significant client. Seeking stability, Martel turned to Zenith, which was also exploring alliances at the time. As a result, Zenith became the majority shareholder of Martel in 1959.

It’s important to note that while Zenith offered chronograph wristwatches with its name on the dial and movement since the 1930s, it wasn’t until the 1960s that Zenith became a manufacturer of wristwatch chronograph movements. Before then, Zenith relied on ébauches from Martel and later Excelsior Park. Zenith’s expertise was renowned in other areas, particularly precision. For instance, in 1954, the celebrated Calibre 135 won the Neuchâtel Observatory accuracy competition for five years in a row, contributing to Zenith’s impressive tally of over 2,300 prizes awarded to pocket watches, onboard instruments, and wristwatches over the years.

The story of these accuracy competitions is fascinating in its own right. During the 1960s, René Gygax, the Head of the Accuracy Adjustment (Réglage de Precision) department at Zenith, was a crucial figure in this “sport” and played a significant role in the development of Calibre 3019 C, named El Primero much later. Additionally, Pierre-Alfred Roulet, a young graduate tasked with overseeing the engineering of steel components and scaling up production, made significant contributions to the development process.

The specifications for the “anniversary” movement evolved over time. Initially, the goal was to have a traditional operating frequency. Still, Raoul Pellaton later suggested increasing the frequency to 36,000 vibrations per hour, driven by the growing recognition of the advantages offered by a higher frequency in watchmaking and ongoing experiments across the industry.

From the outset, the specifications were ambitious. They called for an integrated automatic winding system consistent with the traditional integrated chronograph design, featuring a column-wheel mechanism and a central rotor mounted on ball bearings. The movement also had to offer a power reserve of over 50 hours, feature bidirectional winding, and have a slim profile, only slightly thicker than existing hand-wound movements. Precision was crucial, and components had to be designed to be stamped with such quality that they could be assembled without the need for traditional filing.

The development of the movement spanned almost even challenging years, way past the 1965 goal. While some attribute the delay to the complex nature of the task, others argue that management’s uncertainty about the timing of a new mechanical calibre also played a role, as quartz technology was rapidly gaining traction. The original 1965 deadline was missed, with fears that consumer preferences shifted towards quartz. However, in 1967, rumours surfaced that a consortium including Breitling, Hamilton-Büren, Dubois-Dépraz, and Heuer-Leonidas was preparing to launch an automatic winding chronograph of their design. This news accelerated the pace of work at Zenith’s workshops and spurred further progress on the project.

One of the critical technical challenges Zenith’s project team faced was resolved with the introduction of the Clinergic 21 in 1966. This advanced Swiss lever escapement, developed by Fabriques d’Assortiments Réunis (now Nivarox), featured 21 teeth instead of the previous 15. This innovation allowed movements to operate at higher frequencies of 4Hz or 5Hz, compared to the conventional 2.5Hz and 3Hz.

However, higher frequencies brought a new issue: lubrication. Traditional oils, affected by the balance wheel’s high oscillation frequency, could be sprayed onto the balance spring and balance wheel, disrupting the movement’s operation. The solution came in the form of a specially developed dry lubricant, which effectively addressed this problem. In the end, the combined expertise of Martel and Zenith, technological progress, and management’s desire to beat the competition bore fruit.

Episode II – The Official Release of the first High-Frequency Automatic Chronograph

On January 10th, 1969, Zenith unveiled the world’s first automatic chronograph calibre, the 3019 PHC. (Movado, Zenith, and Mondia entered into a consortium the same year, and Movado marketed the movement as Datron HS 360). This launch positioned Zenith ahead of its competitors. The calibre 3019 PHC (30 for the movement’s diameter, 1 is the number of order in which the movement of this diameter appeared, 9 being designation for chronographs, and PHC stands for perpetual, hour counting and calendar) featured remarkable specifications, particularly when compared to the rival Calibre 11 Chronomatic, introduced a few weeks later by Breitling, Hamilton-Büren, Dubois-Dépraz, and Heuer-Leonidas.

While the Calibre 11 was 7.7mm thick, operated at 19,800 vibrations per hour, and utilized a microrotor for winding, the El Primero stood out with its 36,000 vibrations per hour frequency, an automatic winding system, 12-hour and 30-minute chronograph counters and capable of measuring to 1/10th of a second, a 50-hour power reserve, and a date indication – all within a movement only 6.5mm thick while comprising 282 components. 

On the other side of the world, Japanese watchmakers at Seiko also unveiled that same year the Calibre 6139, a 27mm integrated column wheel chronograph with vertical coupling and beating at 21,600 vibrations/hour. Even if Seiko’s vision was more modern, cost-effective and focused on industrialisation, this movement was nevertheless technically advanced too – it was the world’s first automatic chronograph with a column wheel and vertical clutch. The 1969 trilogy of inaugural automatic chronographs resulted in highly different takes on the concept, all with true mechanical interest. 

The introduction of El Primero led to a flurry of activity in Zenith’s workshops in Les Ponts-de-Martel and Besançon as they began assembling watches equipped with this groundbreaking calibre. Notable models launched between 1969 and 1972 included the A384, A385, A386, A781, A787, and the triple-calendar version of the El Primero, the A7817 “Espada,” as well as the steel and gold-cased G381, G582, and G7810. Due to management’s cautious approach, production numbers were relatively low (1,000 to max 4,500 pieces). These El Primero watches proved highly reliable, but despite positive media reviews and advertising efforts, El Primero failed to lift the company’s fortunes significantly. Challenging circumstances persisted, ultimately leading Zenith to seek a new alliance, resulting in the sale of the company to American owners.

Episode III – The Temporary end of El Primero under American control

In 1971, Zenith was acquired by the Chicago-based Zenith Radio Corporation, a manufacturer of radios and TV sets. However, the US management of Zenith Watches SA eventually lost faith in the future of mechanical watchmaking and shifted their focus to quartz technology. As a result, the company decided to halt the production of mechanical movements in 1975. In 1976, the decision was made to sell the metal presses and tools required for manufacturing mechanical movements by the ton to the highest bidder. The rest is common knowledge.

Enter Charles Vermot, the man with the guts and the vision. He was the Zenith watchmaker in charge of the El Primero workshop where the chronograph was meticulously assembled through no fewer than two thousand operations. When the suits upstairs decided to scrap mechanical watchmaking in favour of quartz, Vermot knew they were throwing away the soul of the craft. He believed, with every fibre of his being, that mechanical watchmaking had a future. So, he made his case to the US management, asking to keep all the tools necessary for El Primero’s production in a small, dedicated workshop. His request was met with a resounding silence.

But Vermot wasn’t just going to give up. He knew the value of those tools and the unique know-how they embodied. So, he took a risk – a big one. With the help of his brother Maurice, a Zenith employee, they orchestrated a covert operation. By night, they spirited away the presses, cams, cutting tools, and manufacturing plans – all the lifeblood of the El Primero movement. They ferried the heavy equipment through a passage at the back of the building and up some 50 steps to an isolated store on the top floor.

In six months, Vermot and his brother managed to save about 150 presses. Imagine the scene: these two brothers, lugging thousands of Swiss francs’ worth of stuff up to the attic at night, where Vermot went so far as to build a wall to hide the treasure trove. A treasure worth at least a few million Swiss francs, walled in and waiting for mechanical watchmaking to rise again. And so it sat there, hidden away, biding its time for a few years, like a secret waiting to be unveiled. It is interesting to see that an almost identical story came to happen to another legendary chronograph movement, the ETA Valjoux 7750, which survived thanks to a man named Edmond Capt, who defied orders, discreetly stored as many tools and documentation as he could, and then made possible the relaunch of the 7750.

Episode IV – Zenith Back under Swiss control, El Primero revived with Rolex and Ebel backup

Dissatisfied with mounting losses and eager to offload the weight of it all, Zenith Radio Corporation offloaded Zenith Watches SA in 1978. The buyers? A trio of Swiss manufacturers, including Paul Castela from Le Locle, were driven by a noble quest to preserve the Swiss industrial and watchmaking legacy embodied by Zenith. And then, as if by fate’s design, Zenith’s fortunes began to turn – thanks to El Primero.

Enter Pierre-Alain Blum, president of Ebel, who “stumbled” upon a stash of unfinished El Primero movements. Like a treasure hunter striking gold, he snapped them up for use in Ebel chronographs, rebranding them as the Ebel calibre 134. This discovery set the stage for a pivotal twist in Zenith’s narrative. In the early 1980s, Rolex came knocking on Blum’s door, seeking to breathe new life into the Daytona, which had long relied on the manually wound Valjoux 72. Long story short, Pierre-Alain Blum was hired by Rolex to fit El Primero for the Crown’s needs.

The ensuing partnership culminated in a ten-year contract inked in 1984, tasking Zenith with the production of El Primero movements for Rolex. Naturally, without the foresight and audacity of Charles Vermot, this grand deal would’ve been a pipe dream. Thanks to Vermot’s clandestine preservation efforts, the El Primero was ready and waiting to roar back to life (manufactured), poised to power a new generation of Rolex Daytonas.

The first specially modified El Primero-equipped Daytonas (ref. 16520) were unveiled in 1988. Around 200 modifications were made to the Zenith calibre to meet Rolex’s specifications, now referenced as calibre 4030. The date mechanism was removed, the balance wheel was replaced with one made of Glucydur, and the regulator assembly was swapped for Rolex’s Microstella, reducing the operating frequency to 28,800 vibrations per hour. The flat balance spring was replaced with a Breguet overcoil, traditional lubricants were reinstated, and the rotor and column wheel were redesigned.

The arrangement with Rolex brought much-needed stability and funds to Zenith. As the company resumed producing mechanical movement components in 1984, it began updating the El Primero. By 1987, several improvements had been made, including an upgraded shock protection system. This enhanced version was designated calibre 400, moving beyond the classification inherited from the Martel Watch. Similarly, the 3019 PHF, which featured a day of the week, month, and moon phase indications and was initially introduced in 1969, was rebranded as calibre 410.

For the next decade, the calibre 400 remained unchanged until the introduction of the 400Z and 410Z in 1998. However, in 1997, the El Primero family saw a significant addition with the debut of calibre 405, a high-frequency flyback chronograph movement. This development was initially sparked by tenders from the French military, which ultimately did not lead to a partnership. Nonetheless, it resulted in the creation of the El Primero Rainbow Flyback and a welcome innovation that expanded the collection.

In 1998, the 400 Z and 410 Z movements introduced several modifications to enhance the El Primero line. These updates addressed a rare but potential issue where the juxtaposition of teeth could occasionally stop the watch when manually wound, leading owners to believe the mechanism was faulty mistakenly. The changes included a new design for the chronograph bridge and alterations to the seconds wheel and escapement. The seconds (fourth) wheel now featured 120 teeth and six arms, an increase from the previous 100 teeth and five arms. Additionally, the number of escapement teeth was reduced from 21 to 20, a blade was added to the pinion, and the horns of the lever fork were modified. Similar improvements were applied to the El Primero calibres 405 Z and 420 Z, with the latter being a notable curiosity as a manually wound version introduced in 1993.

Episode V – El Primero in the new millennium

In 1999, Zenith joined the LVMH group, ushering in new opportunities for growth and innovation. This change, coupled with a renewed customer interest in mechanical watchmaking, paved the way for further advancements in chronograph development. From 1969 to 1999, Zenith referenced ten El Primero versions. Today, that number has grown to nearly a hundred, with many notable models worth mentioning.

In 2003, Zenith introduced the El Primero calibre 4003, which combined chronograph and perpetual calendar functions, powering the Zenith Academy Quantieme Perpetuel. This was followed by calibres 4005 and 4005 C in 2004, featuring a tourbillon regulator with a disc-type date display on the tourbillon, as seen in the Grande Chronomaster XXT and Tourbillon Concept models. Introduced in 2007, the Grande Class Traveller Minute Repeater calibre 4031 offered a chronograph function with a big date with an instantaneous date change, a minute repeater, an alarm function with two signal tones and vibration alarm, a second timezone and a triple power reserve indicator for movement, alarm function and repetition. Impressive, as a grand complication watch, it is still an El Primero movement, yet it is the El Primero Striking 10th that was introduced three years later that feels more in line with what we’ve come to love about this movement family.

The Striking 10th calibre 4052 with jumping seconds, launched in 2010, offered a clear display of the 1/10th of a second, all thanks to an ingenious invention involving a complex mechanism with three wheel trains, with the one for jumping seconds function, which made 1/10th of a second reading easy.

Zenith pushed the boundaries further with the Defy El Primero 21, which showcased a 1/100th of a second hand on the central axis, made possible by a 50Hz operating frequency. This was done by adding a secondary regulating organ, next to the timekeeping part beating at 5Hz, which engages when the chronograph is activated.

In 2019, to celebrate the 50th anniversary of the El Primero, Zenith unveiled the calibre 3600. This new evolution was designed with a focus on production optimization and featured a modular design, enabling the integration of additional complications. Despite these modernizations, the El Primero 3600 retained the defining characteristics of its high-frequency predecessors. It included an integrated flyback chronograph construction with a column wheel and lateral clutch, capable of measuring time to the 1/10th of a second. The movement also featured a stop-second mechanism and an improved power reserve, now offering 60 hours of autonomy. The design was simplified, with fewer components, making it more efficient and easier to service. Subsequent variations, like the calibre 3620, featured a 1/10th of a second-hand directly driven by the 5Hz escapement, further refining El Primero’s legacy. This movement is found in the Chronomaster Original and Chronomaster Sport.

Editor’s notes

The El Primero 400 was employed across the LVMH watch division, powering timepieces from Bulgari, TAG Heuer, and Hublot. Before the group decided to reserve it exclusively for internal use, this legendary calibre also found its way into Panerai’s creations, serving as the foundation for their OP IV and OP VI movements. Brands like Boucheron, Daniel Roth, and about 20 other companies relied on this remarkable movement to build their chronograph series.

As you can see, El Primero’s history is a captivating journey spanning over 50 years, marked by fascinating technical and technological innovations. It serves as a window into the evolution of watchmaking, the corporate machinations behind the scenes, and the trends that have shaped the industry. We extend our heartfelt thanks to all the trailblazers who previously delved into El Primero’s history, making this summary, aimed at sparking a deeper exploration of El Primero, possible.

Released in the same year as the now long-gone Calibre 11 Chronomatic and Seiko’s 6139 automatic chronograph movements, the El Primero calibres have remained true to their high-frequency roots, continuously exciting and innovating since their inception in 1969. The King of chronographs, as envisioned and designed, keeps its regal beat alive.