automatic chronograph movement by Zenith/Movado as well as a series of watch models with the same name.
In the late 1960s there was a prestigious race to develop the world's first mechanical chronograph with automatic winding Heuer-Leonidas and Dubois Dépraz had initiated the secret “Project 99” to develop such a movement, bringing in Hamilton/Büren and Breitling. On March 3, 1969, this group presented their product under the name of “Chronomatic” simultaneously in Geneva, New York, Hong Kong and Beirut. The barrel of the Chronomatic is wound by means of an eccentric weight segment, a concept called a “microrotor”.
Realizing that this announcement was imminent, Zenith rushed to preempt them. Their Cal. 3019 "El Primero" movement (“The First”) was unveiled in a quiet press conference in Geneva on January 10 of the same year. They had begun developing their integrated automatic chronograph at the beginning of the decade, with the project stalled and restarted later. By late 1968, a few El Primero prototypes had been produced and these were shown to the world in January. It was not until late in 1969 that Zenith was able to produce customer-ready movements and watches. By this time, both the Chronomatic and Seiko 6139 were already in production and available to customers.
The development of the El Primero had already begun in 1967. While the Calibre 11 “Chronomatic” only made 19,800 semicycles, the El Primero oscillated with 36,000 semicycles, which was unusual for the time. In the 1960s the engineers at Zenith had succeeded in doubling the frequency of 18,000 oscillations. (See also High-beat)
This result is unsurpassed even today and has led many large watch manufacturers to equip its chronograph models with this unique movement. Among others, Rolex used it in their model Cosmograph Daytona, but here the amplitude was taken back to 28,800 A/h. (See Rolex 4030) (In the meantime Rolex has their own in-house made chronograph calibre, the Rolex 4130.)
The first model of the 'El Primero' was available in two versions Cal. 3019PHC had the unmistakable date display at the 4 00 location while Cal. 3019PHF featured the day, month and moon-phase indication. The weight segment in tungsten carbide registered even the smallest, otherwise not perceptible movements of the wearer's arm. The power reserve amounted to more than 50 hours, the weight segment was embellished by the company logo. The El Primero movement has a diameter of 30 mm and with only 6.5 mm is very flat. Due to its high oscillation rate, it is also the only chronograph movement, which permits a short-term measurement of 1/10 seconds. Other advantages are the instantaneous date change and a dry lubrication on molybdenum-sulfide basis.
After twenty years Zenith incorporated a few modifications into the El Primero movement, which should increase its power and reduce the wear of some components. The winding of the chronograph and the operating the chronograph functions, such as zero reset, were simplified. One of the first pieces is exhibited in the Museum Château des Monts in Le Locle.
Years later, TAG Heuer adopted the El Primero as their “Calibre 36”.
For some time, especially in the 1990s, Zenith named also its sports model collection after this movement El Primero. In 2012, Zenith introduced the first non-chronograph El Primero watch series, the Espada. This was expanded for 2014 with a new movement and family of non-chronograph El Primero watches, the Synopsis, which adds hacking and silicon movement components.
The evolution of the El Primero watch movement mirrors the watch industry from the 1960's to today. It was launched at a time of innovation, when design and manufacturing went high-tech. Not only was the original El Primero movement one of the first automatic chronographs, it was one of the first high-beat chronograph as well. All this was made possible by increased industrialization of the watchmaking process, new materials, and the strength of companies like Zenith.
The El Primero seemed to be a sure-thing, and Zenith used it as a halo for their entire line, just as the Constellation chronometer had been. Throughout that 10-year production run, the company modified the original movement just once, producing just 800 full calendar and moon phase movements.
As the 1970's continued, the market for high-end movements like the El Primero had disappeared. The entire industry turned to more-accurate and inexpensive quartz movements and Zenith suffered mightily. The company changed hands and ended production. As with the Valjoux 7750, one watchmaker inside the company saved the parts and tooling from destruction, and saved the movement for the future.
In the 1980's, it became clear that the market for high-end mechanical watches was recovering and the surviving companies went looking for their glorious past movements. The El Primero was one of the best products of the 1960's, and Zenith was lucky that the tooling was saved. They restarted production in 1985, renaming the movement Cal. 40.0 but leaving it largely unchanged otherwise. Renamed Cal. 400 the next year, it remains in production to this day.
As the 1990's arrived, high-end watch companies recovered and Zenith's El Primero became the envy of the industry. Rolex commissioned their own version for the rebooted Daytona, and Zenith began investing in the movement for the first time in 30 years. They moved the date window from 4 30 to 6 00, a mammoth undertaking requiring relocation of the three sub-dials as well. They also added a complication For the first time, Cal. 405 had a flyback mechanism. Another novel version was Cal. 420, a hand-winding version.
In the 2000's, variations on the El Primero base exploded. The 4000 series, introduced in 2002, added hacking seconds and featured many other refinements. There was a perpetual calendar, big date, power reserve indicator, rattrapante, and more.
Zenith also paired a tourbillon with the high-beat El Primero for the first time, with a series of haute horology pieces developed including a tourbillon perpetual calendar and non-chronograph tourbillon version. Then there was the minute repeater and alarm variant, along with the hand-winding, "chain and fusée" and "Gravity Control" gyroscope versions.
In 2013, Zenith finally produced a version of the El Primero that could count tenths of a second using a semi-foudroyante seconds hand. The "Striking 10th" was a technical wonder, especially when a flyback was added. Zenith also began working with silicon in this decade, introducing versions with a silicon escapement in 2014.