The world’s most complicated watches 2
The doubledialled Calibre 89 from Patek Philippe was created to celebrate the manufacture’s 150 years. Only four of these exist in the world.

The world’s most complicated watches

Masterpieces from Patek Philippe and Franck Muller prove that mechanical watches go head to head with the latest digital technology.
Rheea Hermoso-Prudente | Jan 07 2019


Smart watches these days like to highlight their multiple functions, but they’ve still got nothing on the ultra-complicated mechanical watches that have been made. Take the Calibre 89 from Patek Philippe. Launched in 1989 in celebration of Patek Philippe’s 150th anniversary, the Calibre 89 held the distinction of being the world’s most complicated timepiece until it was dethroned by Franck Muller’s Aeternitas Mega 4 in 2010.

When you’re a watch house like Patek Philippe, known for classical timepieces and technological know-how, you’d naturally want to showcase all your skills and expertise when coming up with an anniversary watch. Such was the case for the Calibre 89. The mandate was for the timepiece to have the most complications in the world and should feature all the traditional watchmaking techniques Patek Philippe had mastered in the past 150 years.

The finished Calibre 89 boasts of 33 complications (a complication is a watch function that goes beyond the basic three hands of time—hours, minutes, and seconds) in five function categories: timekeeping, calendar, chronograph, sound, and operational functions. There are other ways to categorize the complications depending on which expert you refer to. Work on the watch started in 1980, with nine engineers and watchmakers collaborating over five years for the research and development alone, and another four years to come up with an acceptable, working prototype. Only four pieces of Calibre 89 were made, one of each in yellow, pink, and white gold, and another in platinum.

The world’s most complicated watches 3
The Caliber 89 took a total of nine years to make, with five of those dedicated to research and development. The timepiece is meant to showcase the skills and expertise honed by Patek Philippe over the century-and-a-half of its existence.

Despite its magnificent attributes, the Calibre 89 is not a timepiece that you’d want to lug around. All those complications require quite a number of parts; 1,728 in this case, all hand-finished and assembled. These parts, including three barrels, two dials, 24 hands, eight discs, a thermometer, and a star chart fit into a case that is 3.5 inches wide and 1.5 inches thick, and altogether weigh an alarming (pun intended) 1.1 kilos. The sapphire crystals over both dials are cut from a hollow sphere, giving them gentle curves. All the functions of the watch are controlled via 12 external slide-pieces, push pieces, and winders. The watch bears the Poinçon de Genève, or the Geneva Seal of excellence.

So, what can the Calibre 89 do? Pretty much everything you’d need to know about the time, and then some. Some of the more “exotic” functions include the date of Easter, the zodiac (because it’s always helpful to know if Virgo is ascending), time of sunrise, time of sunset, and, of all things, a thermometer. Of course, Calibre 89 also has the more plebeian complications such as the chronograph, second time zone, perpetual calendar, and tourbillon. It also displays astronomical complications such as the sidereal time and equation of time, just in case you need to know the exact time of day, should you want to navigate using the hour-angle of a star, or the altitude of the true sun. Finally, the Calibre 89 also is a grande and petite sonnerie, meaning that it strikes the hours and quarter hours, and a minute repeater, striking the minutes on demand. This calls not only for technical know-how, but also an ear for the melody. This timepiece plays the popular “Westminster Chimes.”

For watch geeks, the more intriguing aspect would be how all the complications fit into the case. If you were to open the watch, you’d see an elegantly-assembled movement on three German silver or maillechort plates on four levels, powered by three barrels (one for the movement and the other two to power the chime and the alarm). The first level, on the main plate, contains the mechanisms for the chime, alarm, 12-hour recorder, and the power reserve indicators for the chime and movement. The second level, on the reverse side of the main plate, holds the mechanisms for mean time, the chronograph, 30-minute recorder, and tourbillon. The third level on the second plate contains the sidereal dial mechanisms: sidereal time, the seasons, solstices, equinoxes and zodiacs, the times of sunset and sunrise, the equation of time, the date of Easter and the star chart. Finally, the fourth level on the third plate supports the mechanisms of the secular perpetual calendar, second time zone indicator, moon phases, and thermometer.

The entire four-piece set was initially bought by a single royal family, but the collection was broken up in the early 2000; the yellow gold one went off to an anonymous collector, the pink gold to an Italian collector, the platinum to a Middle Eastern royal family, and the white gold one was auctioned off by Antiquorum at USD 5 million. There is a fifth watch, the original prototype of the Caliber 89, which is proudly displayed at the Patek Philippe Museum in Geneva.



Compared to the venerable Patek Philippe, Franck Muller is the young upstart (after all, its eponymous founder is still alive and well). When the watch house opened in 1991, Franck Muller, the man, was already known as a genius watchmaker who created exceptional complications. Co-founder Vartan Sirmakes, on the other hand, made cases for luxury watch houses. Together, they shook up the staid Swiss watch industry with their decidedly non-traditional Cintrée Curvex™, case, bright dial colors, and innovative creations.

But it was in 2009, with the launch of the Franck Muller Aeternitas Mega 4 Grande Sonnerie Westminster Carillon, that this watch house sealed its reputation as a force to be reckoned with. Ousting Patek Philippe’s Calibre 89 as the most complicated timepiece ever (though pacifists will point out that the Calibre 89 is still the world’s most complicated pocketwatch, and the Aeternitas Mega 4, the most complicated wristwatch) the Aeternitas Mega 4 one-ups—or rather three-ups—Patek’s offering with a whopping 36 complications, all in a case that you can actually strap onto your wrist.

The wearable Aeternitas Mega 4 is enclosed in the famous Cintrée Curvex™ case in 18-karat white gold, measuring 42 mm x 61 mm x 19.15 mm, or a little over 1.5 inches in width and less than 2.5 inches in length. While that may still seem massive, note that several popular watches measure 42 mm in diameter, and those don’t have anything close to the 1,483 components used in the Aeternitas Mega 4.

The world’s most complicated watches 4
The movement can be viewed through the sapphire caseback, highlighting the watchmakers’ skills and the designers’ brilliant layout of components.

Given the space limitations, designing the mechanisms and laying them out posed quite a challenge. Not only did all the complications have to fit, the visible ones had to be legible, as well as visually pleasing (If you check inside the watch, you can see that Franck Muller made it visually pleasing as well. In fact, you can view part of the movement through the sapphire crystal caseback). The use of the unusual Cintrée Curvex shape for the movement also added to the difficulties in design. It took Franck Muller five years of research and development before the very first watch was released to American collector Michael J. Gould, who, after parting with USD 2.7 million, flew to Monaco to pick up the watch.

Franck Muller’s commitment to creating a magnificent yet useful timepiece manifests in the beauty and logic of the dial. The 12-hour chronograph retrograde counter and the retrograde date indicator spoon at 12 o’clock. Immediately below, on the left and right sides of the dial, are the indicators that show whether the sonnerie is activated and whether it is the grande or petite sonnerie that is engaged. Incorporated into the display are the sonnerie power indicators. Below those are subdials that show the days and equation of time on the left and the months on the right, together with chronograph minute counter. Over and below the central hands—including the minute and hour hands, and the rattrapante hand and chronograph hand—are the small displays of the moon phase and the year indicator. Further below are the 24-hour indicator on the left, and the leap year indicator on the right. Below, flanking the tourbillon at 6 o’clock, are two additional time zones. Nine pushpieces and a crown control all the watch’s functions.

As with the Calibre 89, the Westminster Carillon Grande Sonnerie, Petite Sonnerie, and minute repeater are among the notable complications. Aside from the melodious chiming of the hours, quarter hours, and minutes, the mechanism also features a dummy-proof safeguard: you cannot set the time while the chimes are in use, and the chimes cannot ring while you are setting the time.

The Aeternitas Mega 4 is a by-order-only watch, available in New York and Geneva.


This story first appeared in Vault Magazine Issue 17 2014.