A short story from the first breath in 1977 to the new Calatrava Ref. 600640 years Patek Philippe caliber 240

At Baselworld forty years (or 7.6 billion semi-oscillations at a frequency of 3 hertz) ago, a movement started ticking that would go on to write history: the Patek Philippe caliber 240. It advanced the slender gold hour and minute hands of a Golden Ellipse men's wristwatch which redefined elegance by virtue of its unique shape in a decidedly svelte format.

But unlike ultra-thin watches in that epoch, it did not need to be manually wound. It was self-winding. In the middle of the watch crisis, during which cheap quartz timepieces threatened the very foundations of the Swiss watchmaking industry, the Genevan manufacture had the courage to invest in a new mechanical movement and build up fresh momentum for the more than 500-year-old heritage of genuine watchmaking artistry.

Those years were critical for the world-famous Swiss watch industry, at a time when Philippe Stern prepared himself to assume the directorship of Patek Philippe in 1976. In 1932, during the Great Depression, the Stern family had acquired the manufacture from the descendants of its founders, and now, he and his father, company president Henri Stern, were tasked with guiding the eminent enterprise out of a crisis that meant sink or swim for an entire industry. Many competitors had already switched over to quartz watches and liquidated their manufacturing resources. But the Sterns always had somewhat different perspectives, even though in the late 1960s, Patek Philippe was involved in the development of the legendary Beta 21 quartz movement. The manufacture mastered the technology, but its heart kept beating for mechanical timepieces.

An elegant strategy for safeguarding the future

This is why, in 1976, manufacture president Henri Stern and his designated director Philippe Stern formulated a bold plan: the development of an irresistibly elegant self-winding movement that would outperform its quartz counterparts. Not with respect to rate accuracy and not in the low-end price range, but instead in indisputable categories such as beauty, reliability, longevity, intrinsic value, and elegance. They were convinced that the values upheld by Antoine Norbert de Patek and his partner Jean Adrien Philippe were timeless. They would outlast generations of people and technologies. Yet in the middle of the watch crisis, it took considerable entrepreneurial mettle to invest money in the development of a new self-winding mechanical movement. It would have to be a very slender movement because svelte watches radiate elegance. This ruled out a central rotor. Nevertheless, the first prototype landed on Philippe Stern's desk six months later. Its most prominent feature was a very small, off-center winding rotor completely recessed in the plate plane. Accordingly, the movement wasn't thicker than a flat manually wound movement.

Of course, a small planetary rotor could not build up the same winding power as a large and massive central rotor. But the engineers in technical director Gérard Berret's team had the answer. The mass of the off-center rotor was increased with 22K gold. The unidirectional winding concept reduced friction losses because no reversing gear was required. Overall efficiency from the winder and the spring barrel to the escapement was further improved with a totally new going train featuring optimized toothing geometry and polished teeth. And not least, the frequency of 3 hertz (21,600 vph) reduced the energy consumption of the movement by more than 20% in comparison with conventional 4-hertz movements. Even today, it is clear that this is not a disadvantage: All movements based on the caliber 240 operate at 3 hertz and have a rate accuracy that fulfills chronometer precision standards.

The caliber 240 constitutes the foundation of an entire movement family

The career of the caliber 240 began in 1977 when it was chosen to power the ultra-thin Ref. 3738 Golden Ellipse with hour and minute hands. Since 2001, it also ticks inside the classic Calatrava Ref. 5120 with a hobnail bezel and since 2014 in the Ladies' Calatrava Ref. 7200 with the Officer's-style case. From its launch onward, the caliber 240 has proven to be a movement that can consummately handle many other functions.

In 1985, it stood out in the caliber 240 Q (Quantième Perpétuel) version with a height of only 3.75 mm in the legendary ultra-thin Ref. 3940 Perpetual Calendar which in the course of time was followed by a series of elegant successors. From 1991 on, in the caliber 240 PS version, it ticked inside the Ref. 5000 with its unusually positioned subsidiary seconds dial between 4 and 5 o'clock. The same subdial is a hallmark of the Ref. 5015 that dates back to 1994. With moon phases and a power-reserve indicator, it was the first model of the "useful complications" collection, a milestone in the history of the manufacture. From 1997 to 2004, its caliber 240 PS IRM C LU also powered the celebrated Ref. 5055 with the broad, smoothly polished bezel.

Further horological highlights that thrilled both the public and insiders followed, including the World Time watch Ref. 5110 (caliber 240 HU) in 2000, the Celestial Ref. 5102 (caliber 240 LU CL C) in 2002, the first complicated Nautilus Ref. 3712 (caliber 240 PS IRM C LU) in 2005, and the Ladies First Perpetual Calendar Ref. 7140 in 2012. All of them demonstrated the versatility and dependability of the basic caliber 240 movement.

Launched in 2008, the Calatrava Ref. 5180/1 "Squelette" with the caliber 240 SQU movement is an extraordinary timepiece. It is skeletonized and engraved entirely by hand and offers fantastic views and insights into its mechanical heart.

The caliber 240 as an innovation driver

Since its world debut in 1977, the caliber 240 has been optimized in many respects but still retains its original DNA. It still beats with a frequency of 21,600 semi-oscillations per hour but now with a patented Spiromax® balance spring in Silinvar® manufactured by Patek Philippe that achieves even better rate accuracy. The tooth profiles of the going train were further optimized as well to reduce wear, improve accuracy, increase the power reserve and boost long-term reliability. In the Ref. 5550 Perpetual Calendar "Patek Philippe Advanced Research", the caliber 240 movement delivered another innovation thrust in 2011: The Spiromax® balance spring and the Pulsomax® escapement (lever and escape wheel in Silinvar®) paired with the GyromaxSi® balance in Silinvar® and 22K gold constitute the Oscillomax® ensemble that attains previously unmatched results in rate accuracy and autonomy – more than 70 hours as opposed to at most 48 hours in the normal version.

Forty years or more than 7.6 billion semi-oscillations have elapsed since the caliber 240 movement had its debut at Baselworld in 1977. To pay tribute to this anniversary, Patek Philippe is presenting three new models at Baselworld 2017. They emphasize the versatility of the movement and of the manufacture. The debut models are the artistically skeletonized and engraved Calatrava Ref. 5180/1 "Squelette" in rose gold, the Calatrava Ref. 6006 with its strictly graphic look, and the ladies' haute joaillerie Ref. 4899/900, which is set with flawless rare white Top Wesselton diamonds and rose sapphires of different color intensities.