At W&W 2024, one trend that eclipsed all others was the return of complications.

The richness of a watch fair is often measured by the scope of brands and the variety of their offerings. With a record 55 watch brands at this year’s Watches & Wonders, from Patek Philippe, Cartier and Rolex to Raymond Weil, Norqain and Bremont, there was no shortage of variety. However, it’s often the watches with the most horological content that leave a lasting impression. This year, we have witnessed a notably high concentration of such watches, perhaps the highest in recent memory.

Amidst a testing year for the industry, a large number of brands have reacted by reminding the world of the true extent of their ambitions and expertise. This has translated into watches of higher value and greater horological substance across the board. There was indeed a resurgence of complications, but what truly distinguished them was their exotic nature. For the majority of brands, these weren’t just ordinary executions of traditional complications; they were fascinating, out-of-the-box, and highly accomplished.

Highly Sophisticated Perpetual Calendars

The two biggest highlights of the fair – at least for those with a sadistic fascination for how long, irregular periods of time can be encoded in a watch – were perpetual calendar watches. The first was none other than the Vacheron Constantin The Berkeley Grand Complication which with a total of 63 complications surpasses the record held by the 57260. Both of these watches were commissioned by finance mogul William Robert Berkley who appears to not only have a deep fascination for highly complicated watchmaking but also the challenges inherent in developing a perpetual lunisolar calendar.

The lunisolar calendar unlike pure lunar ones such as the Islamic or pure solar like the Gregorian aims to reconcile lunar months with solar years, essentially incorporating more astronomical data than any other calendar. As such, it is much more complicated. The Chinese calendar comprises of 12 lunar months that generally alternates between 29 or 30 days a month, based on an approximation of 29.53 days for each month. To synchronize lunar months with solar years, an embolismic month is added periodically, every two to three years, based on the observation of solar terms within lunar months.

The solar year is divided into 24 solar terms, marking specific points along the ecliptic where the sun’s apparent motion corresponds to key agricultural and meteorological events. Each lunar month generally contains two solar terms, each divided into two halves. ‘Zhong Qi’ marks the midpoint, while ‘Jie Qi’ marks the beginning and end of each solar term. If a lunar month lacks one of these halves, it signals a deviation, prompting the insertion of an embolismic month to realign the lunar calendar with the solar cycle. This timing of intercalary month insertion aligns closely with the Metonic cycle, named after the ancient Greek astronomer Meton, who observed that after 19 years, the phases of the moon repeat on or near the same dates of the year. This period of about 19 years (or 235 lunar months) is very close to being an exact multiple of both the lunar month and the solar year. Approximately every two to three years within the Metonic cycle, a 13th month is added to ensure synchronization with the solar year. This occurs about seven times in a 19-year cycle. As you have come to surmise at this point, the timing of the insertion of an embolismic is not fixed yet a fixed cycle has to be established in order to be encoded in a watch. This was achieved based on complex mathematical algorithms, designed to accurately predict lunar and solar phenomena over an extended period. The perpetual calendar is programmed till the year 2200 before a program wheel with internal notches of various lengths on the periphery of the movement needs to be replaced. This program wheel governs whether the year is a common or embolismic year.

The decision not to file a patent, despite having freely shared images of the calendar plate, speaks volumes about the complexity of the mechanism and the manufacture’s sheer confidence in its ability to thwart not just my understanding or yours, but all endeavours to comprehend it. Knowing this quite early on, I must confess that I abandoned any attempt at reading the plate. It is simply an unrivalled masterpiece that gives us a glimpse into the preoccupations and connoisseurship of its owner.

The second perpetual calendar watch that stood out at the fair was the IWC Portugieser Eternal Calendar, which is a secular perpetual calendar that takes into account the common year that occur at the end of every three consecutive centuries and the leap year in the fourth century. The manner in which this was achieved is quite baffling, even more so given that it could be built into the perpetual calendar module developed by Kurt Klaus. In fact, it is difficult to determine if its methods are simple or complex because while the secular module has a low part count of eight, neither the parts nor the arrangement of the parts are conventional and the overall solution is anything but derivable without significant time and effort.

The 48-month cam is designed with four notches of equal depth for the month of February. Every four years, a feeler on the grand lever penetrates the notch and lands on a 400-year cam. This 400-year cam is designed with just three notches distributed successively every 90 degrees to take into account the century years that are common years. It either cooperates with the February notch on the 48-month cam or reduces its depth with its full circumference for the insertion of an additional day. This 400-year cam rotates on an eccentric circular path, meaning it moves in a circular path that is offset from the center of rotation. This offset creates a larger effective path enabling it to dictate the length of February every four years. This arrangement is facilitated through a Maltese cross reduction system. Apart from this, it breaks the record for the world’s most accurate moon phase, accumulating a day of error over an astonishing 45 million years and this was done with just three regular toothed wheels. What was less talked about is its beauty. The effect of having a box sapphire dial that’s lacquered on its underside and further topped by another box sapphire crystal is just so unusual and stunning in person that it almost makes you feel that a patent is warranted.

Tourbillons Everywhere

Tourbillons, while not strictly complications, but regulating devices, made up a significant number, with at least 10 showcased across the board. What’s interesting is the sheer variety, from ultra-thin to multi-axis to central tourbillons, which continues to demonstrate that employing the most basic concept of a tourbillon as a regulating device is no longer sufficient.

What is more keenly felt in these exotic tourbillons is that a tourbillon does not operate in a vacuum; at the very least, the rest of the movement has to be completely re-evaluated to accommodate it, and in some cases, entirely rearranged. Simultaneously, the design of the tourbillon is inseparable from the overarching purpose and design of the watch in addition to their basic function. As such, they are inarguably complicated and a far cry from the original character and construction of the tourbillon invented by A.-L. Breguet. Determining a clear winner is elusive, given the stark contrast in their intended purposes and the distinctly unique solutions they each offer.

For Piaget, the goal of the tourbillon was to demonstrate prowess in ultra-thin watchmaking. The Altiplano Ultimate Concept Tourbillon sets a new world record as the thinnest tourbillon ever created at an astonishing 2 mm high, the same thinness as the original record-setting time-only Altiplano Ultimate Concept from 2018, which is equivalent to two stacked credit cards. While the race to make wristwatches ever thinner has been on in earnest for several years now, Piaget is the only brand that has made the preservation of classical watchmaking part of the equation; the AUC Tourbillon looks and feels like a traditional watch which makes its accomplishments seem all the more remarkable.

While the calibre 970P-UC in the AUC Tourbillon generally appears to be very similar to the AUC’s calibre 900P-UC in terms of fundamental layout, they are almost entirely different. A total of 90% of the components had to be redesigned, most crucially the mainspring, which had to accommodate a 25% increase in inertia caused by the cage, and the going train, responsible for driving the one-minute rotation of the cage. The tourbillon employs several radical solutions to shave off every possible micron from the thickness of a traditional construction. A tourbillon assembly typically consists of four to five layers that is sandwiched between the main plate and a slender bridge – an upper cage bridge, balance wheel, escapement and its bridge, and a lower cage bridge. In the AUC Tourbillon, however, the lower bridge is milled to accommodate the escapement on the same layer while the upper cage bridge accommodates the balance wheel, resulting in just two layers. The upper and lower cage bridges are made of titanium. In contrast to a standard tourbillon whereby the cage is driven by the last wheel of the going train via a pinion beneath the cage, the cage of the AUC Tourbillon consists of a spokeless toothed wheel that is sandwiched between the two titanium plates and secured together by screws.

This wheel is driven on its periphery by the last gear in the going train which further reduces the construction by one layer. The cage itself is fixed in a ceramic ball bearing on its periphery, like the mainspring barrel, eliminating the need for a traditional pivot and a jewelled bearing, which adds height. As such, the balance wheel can be positioned offset from the central axis of the cage in order to avoid overlapping the escape wheel pinion. The balance wheel itself also runs on a ball bearing, allowing it to do away with a jewelled bearing. Normally, the outer end of the hairspring is secured to a stud and attached to a stud holder, which is mounted on the balance cock. Here the hairspring is attached to the underside of the balance wheel rather than above and the stud holder is secured to the lower titanium plate which also serves as the pallet fork bridge. The balance wheel is free-sprung with turnable inertia weights that are recessed into its rim, and it notably maintains a frequency of 4Hz. All things equal, a higher frequency places greater demands on the movement construction and power management, but it is nonetheless key to rate stability in a wristwatch. The AUC Tourbillon is an extraordinary accomplishment and the fact that it feels relatively robust and maintains the look and feel of a traditional watch is deeply satisfying.

On the opposite end of the spectrum are multi-axis tourbillons which are somewhat of a posterchild for the evolution of tourbillons. They are no doubt intended to beguile the eye but their existence is fundamentally rooted in very practical purposes – to compensate for the effects of gravity in the various positions that a wristwatch may find itself in. This year, two multi-axis tourbillons stood out for their uniqueness even within the sub-category of multi-axis tourbillons. The first was Jaeger-LeCoultre Duometre Heliotourbillon Perpetual, which combines a perpetual calendar with the brand’s first ever triple-axis tourbillon. Given the brand’s long history with multi-axis tourbillons, it’s something of a surprise to find that the company has never done a triple-axis tourbillon.

The Heliotourbillon Perpetual makes the most out of the Dual Wing concept by replacing the analog hand for the date with discs as well as adding a four digit year. Discs require more inertia than hands and the Dual Wing concept is most useful when power is used unevenly. One gear train powers the perpetual calendar, which means it powers the motion works and the hours and minutes, while the other gear train is dedicated to the tourbillon which doubles as the seconds indicator.

The tourbillon is visually impressive; the first two cages are perpendicular to each other and completes a rotation in 30 seconds each while the third cage is inclined at a 40 degree angle and makes a revolution in one minute serving as the seconds indicator. In addition, it is fitted with a cylindrical hairspring. One of the primary benefits of the cylindrical hairspring is its concentric development. Unlike flat hairsprings, which may exert force unevenly on the balance pivots due to their non-concentric nature, the cylindrical hairspring works perfectly along the axis of its pivots. This leads to improved isochronism, ensuring more consistent timekeeping. Both the tourbillon and cylindrical hairspring make for a showstopper and that’s often the point of their existence in a watch but it doesn’t diminish the fact that they are valuable innovations in horology developed in a time when advancing the science of timekeeping was the sole priority.

The second multi-axis tourbillon was the Hermès Arceau Duc Attelé which is also a central tourbillon and a minute repeater. Central tourbillons are historically a rather rare genre since Omega patented the first in 1995, and multi-axis central tourbillons are even rarer. The central positioning of the tourbillon within the movement requires a redistribution of components around it, most obviously the gear train, but potentially harder to go about are the keyless works for winding and setting as well as the motion works as there are no traditional hands. Adding to the complexity, the triple-axis tourbillon houses a 5Hz balance wheel, making it the first of its kind. While a triple-axis tourbillon helps to improve timekeeping accuracy by averaging out timing errors caused by gravity in virtually all possible orientations of the balance wheel, the frequency of the balance wheel remains relevant for its resilience to external disturbances; a higher frequency improves the stability of the balance motion in the face of shocks. This in turn also means that additional power must be expended on it in addition to powering three cages.

As a result of placing the tourbillon at the centre on the front, the strike works had to be located on the back while the hammers and gongs are located on the front. Most striking is the unusual shape of the hammers and gongs. In a conventional repeater, there are two circular gongs made out of hardened steel wire, tuned to two different notes that encircle the movement once in opposite directions. In this design, the gongs feature a ‘tuning fork’ structure with elongated U-shaped branches. Despite encircling the movement only once, due to its dual branches, the sound it produces is akin to that of a cathedral repeater, where the gongs encircle the movement nearly twice. The minute repeater hammers themselves at five and seven o’clock take the shape of a horse while the quarter rack visible on the bridge side of the movement forms the silhouette of a horse’s head.

Roger Dubuis also released the impressively executed Orbis in Machina Central Tourbillon. Central tourbillons are generally pursued for their visual impact and this is perhaps the most immersive where aesthetics and mechanics are seamlessly integrated. The presentation of time is characterised by a stunning concentricity; the hours, minutes and seconds are indicated on three concentric rings on different elevations. The seconds is indicated by a gold tipped hand on the tourbillon cage while the hours and minutes are indicated by open-worked hands that are mounted on ball bearings. This required the development of a planetary gear system to ensure the hands can be safely disengaged for time-setting. But while the dial has a machine-celebratory architecture that sets the stage for the tourbillon, the case back reveals classic idioms of traditional fine watchmaking. The wheels are held in place by finger bridges and are decorated with striping and anglage while the base plate is adorned with perlage. The watch remarkably impressive in person and it’s one of those instances where its grandiose case diameter of 45mm is integral to its appeal.

Elsewhere, H. Moser & Cie. unveiled the Streamliner Flying Tourbillon Skeleton with a dramatically open-worked automatic tourbillon movement that is highly captivating in person. Apart from having the tourbillon cage driven on its periphery to reduce overlapping, all the bridges, along with what’s left behind of the oscillating mass, are exceptionally slim and consistent in thickness throughout, creating a visual experience that is unexpectedly striking. Grand Seiko also released a very stunning version of the impressive Kodo Constant-Force Tourbillon, with brighter plating on the movement parts that brings greater clarity to its intricacies and finishing.

Beyond the fairgrounds, there were two watches that were just as outstanding in their beauty as they were incredible pieces of watchmaking. The first was the De Bethune DB Kind of Grande Complication. It is a testament to over two decades of De Bethune’s pioneering ingenuity in aesthetics and mechanics. The watch has a reversible double-sided case suspended in between articulated lugs. The first side displays a perpetual calendar and the high-precision spherical moon phase display against a blued titanium dial scattered with white gold pins, representing the stars. On the reverse is a rather iconic scene, featuring a delta shaped bridge that supports two self-regulating barrels. Flanking it is a power reserve display and a retrograde age of the Moon indication while directly above, a blued titanium bridge supports the deadbeat escapement. At six o’clock is the brand’s signature high frequency (5Hz) and high speed (30 seconds) tourbillon. Notably unusual for tourbillon watches, it has a deadbeat seconds, central seconds, and a hacking seconds.

It seems apt to end the section with a tourbillon that is firmly within the realm of traditional fine watchmaking both in character and execution. The Voutilainen Tourbillon 20th Anniversary wristwatch is one of the finest examples of a classical tourbillon. It was inspired by his very first pocket watch which he completed in 1994 while still working at Parmigiani. Having begun his career restoring antique timepieces, the pocket watch showed the influence of past masters, namely Breguet.

The anniversary wristwatch has an elegant asymmetrical dial with an off-centered chapter ring, a fan-shaped power indicator at eight o’clock and a subsidiary seconds at five o’clock. The movement runs at a traditional 2.5 Hz with a 72-hour power reserve. It has two large mainspring barrels arranged in a parallel configuration for high torque and the layout is a beautiful, logical, classical execution of a traditional tourbillon gear train. The details are exceptional. The gilt colored frosted bridges are beautifully shaped to create significant depth at the centre. Like the pocket watch, the centre wheel is supported by a black-polished and angled steel bridge screwed to the barrel bridge, the tourbillon bridge is domed and polished and the cage has rounded, polished arms.

Chronographs

The only chronograph launched at the fair that was developed from scratch was the Cartier Privé Tortue Monopoussoir Chronograph. It is unquestionably a very handsome watch that draws inspiration from two CPCP models launched in 1999, specifically the Ref. 2356 and the Ref. 2396. Launched in yellow gold and platinum, the case is just a tad larger than the original, measuring 34.8mm by 43.7mm compared to the CPCP’s 34mm by 43mm. More importantly, the Privé Tortue Monopoussoir has a brand new chronograph movement developed in collaboration with Le Cercle des Horlogers. Being a form movement that fills a slightly larger case, there was ample space for a traditional horizontal clutch. The movement was enthusiastically received by both enthusiasts and critics, whose views are valid with regards to the lack of micro-gearing on the chronograph runner; the number of teeth is generally double that of the clutch wheel to reduce the risk of stutter. But overall, you could do a lot worse than a shaped movement with a proper clutch built exclusively for the Tortue. It is a notable upgrade over the movement used in the CPCP, which was circular with a compact and cost-effective oscillating pinion coupling system, and it’s very beautiful.

Another notable launch was the TAG Heuer Monaco Split Seconds, the brand’s first rattrapante chronograph wristwatch. Housed in a titanium Monaco case, the TH81-00 movement was produced in partnership with Vaucher and relies on the superb high frequency base calibre non-rattrapante Vaucher SEED WMF 6710. High frequency rattrapante chronographs are exceptionally hard to come by and I can’t think of any other movement off the top of my head. It relies on a vertical clutch, has the characteristic one-piece reset hammer and free-sprung balance. It uses titanium plates and bridges and power reserve remains at 65 hours.

While it is priced way out of the ballpark of TAG Heuer watches, it is reasonable relative to the other watches with derivatives of the same movement, namely the hand-wound rattrapante watches from Parmigiani, and is about a third the price of the RM 65-01 Automatic Split-Seconds Chronograph.

The newly launched Parmigiani Toric Rattrapante indeed uses the same high frequency Vaucher base movement but with solid rose gold base plates and bridges, which are elaborately skeletonised to showcase an abundance of internal angles. The chronograph is part of the newly revamped Toric collection, featuring full gold cases, dials and movements. The watch is exceptionally beautiful inside and out. Measuring 42.5mm by 14.4mm in thickness, the case is likewise in rose gold with a knurled bezel. But perhaps the most seductive aspect of the Toric watches are the dials. I was told that it was Michel Parmigiani himself who personally demonstrated and instructed the dial makers at the Quadrance et Habillage manufacture on how to achieve the exceptionally fine grained finish. The dials are grained by hand using a mixture of cream of tartar, crushed sea salt and silver mixed with demineralized water to form a paste. Following the application of this paste, the dial is delicately polished with specific brushes to create a refined textured surface that exudes a gentle luminosity.

And then there is the Duometre Chronograph Moon. The new caliber 391 builds on Duometre calibre that was first introduced in 2007. Among the three new Duometre models launched, the twin barrels and gear trains concept remains most useful in a chronograph as it is the complication that requires a substantial burst of power. Such disruption impacts amplitude, which in turn affects rate. The Duometre Chronograph Moon also has a foudroyante with a 1/6th second hand that makes one full revolution per second at the six o’clock counter, a moonphase display in the chronograph hours and minutes counter at two o’clock and a day-night indicator within the mean time hour and minutes sub-dial.

Winding the crown clockwise powers the timekeeping gear train and winding it anticlockwise powers the chronograph gear train. Each gear train also has its own escape wheel and both are mounted on the same axle. Unlike clutchless systems with completely independent gear trains and oscillators, the Duometre does have a clutch in the form of a six-point star wheel that also drives the foudroyante. It is this star wheel that connects the fourth wheel in the chronograph gear train to the escape wheel when the chronograph is activated. When the chronograph is stopped, a lever blocks the star wheel from engaging the escape wheel. Even after years and decades have passed, the concept of the movement remains compelling and moreover, it is now housed in a more refined and elaborate case.

This year also marks the 25th anniversary of one of the most exemplary, complete and beautiful manually-wound chronographs ever created – the Datograph. Even after a quarter of a century has passed and watchmaking has by and large expanded with the rise of independents, the movement remains without peer. For the occasion, A. Lange & Söhne unveiled the glorious Datograph Perpetual Tourbillon Honeygold “Lumen”, along with the first-ever Datograph in white gold. The Datograph Perpetual Tourbillon Honeygold “Lumen” combines a flyback chronograph with instantaneous minutes, an instantaneous perpetual calendar, and a stop-seconds tourbillon, inside a Honeygold case with a Lumen dial. The lustre of honey gold is incomparable – neither yellow nor rose gold – while the Lumen dial makes a magnificent lightshow out of one of the most densely packed Lange dials, thanks to the perpetual calendar mechanism. It’s simply mesmerising and the ultimate Lumen model.

Automatons

One aspect of complicated watchmaking that often doesn’t get enough credit are automatons. While they don’t fit the traditional definition of complications, serving more as mechanical entertainments rather than functions, they are certainly far rarer than complications. Chronographs, tourbillons and minute repeaters in general follow a familiar template – and how far they deviate from the norm to achieve a certain goal determines the degree of innovation – but automatons represent a segment where boundaries are elusive to start with. They are intricate mechanical devices that feature moving parts or figures, often designed to perform specific actions or simulate scenes while indicating the time. These mechanisms are typically powered by springs, and their movement is controlled by a series of cams, levers, racks and gears that are often in configurations you would never expect to see in a watch.

There were two automatons at the fair that stood out. The first was the Chanel J12 Atelier Couture Automaton, which marks the brand’s latest in-house movement – the Calibre 6. The base calibre follows the general theme of Chanel’s calibers with a highly refined architecture, characterised by pair of serially coupled barrels that drives a gear train in a distinctive circular layout. The automata, on the other hand, took five years to realise. The dial features a humorous cartoon figure of Coco Chanel and a dressmaker’s mannequin that come to life on demand. They are powered by a spring located on the dial side which is tensioned when a button at eight o’clock is pushed. The mannequin seems to be driven by an unusual sector gear with an integrated coiled spring.

While the J12 embraces a mechanistic approach to infuse whimsy into its motion, there’s a brand that excels in creating the most naturalistic animations: Van Cleef & Arpels. This year it unveiled the Lady Arpels Brise D’Été Watch which is somewhat of a sequel to the highly complex and magnificent Lady Arpels Heures Florales. This time, two butterflies fashioned from yellow and white gold adorned with plique-à-jour enamel, take turns to mark the passage of time across a 12-hour scale, with each butterfly representing day time and night time hours respectively. However, when the case pusher at eight o’clock is activated, these enchanting creatures gracefully traverse the dial, while the stems of the flowers – whose petals are in vallonné enamel – sway as if gently stirred by a summer breeze. Like the Lady Arpels Heures Florales, the module is built atop and around a small automatic base movement with a full, circular gold rotor visible on the case back. An additional barrel and gear train are implemented on the periphery of the base movement and is controlled by a centrifugal governor which regulates the speed at which the butterflies and flowers move. It is an exceptional piece of watchmaking that wears its complexity lightly and moreover lends itself to highly exotic métier d’arts.