Monochrome Watches
An online magazine dedicated to fine watches

Review – Patek Philippe Advanced Research Aquanaut Travel Time Ref. 5650G (And History of the Advanced Research Program)

| By Tom Mulraney | 10 min read |
Patek Philippe Aquanaut Travel Time Ref. 5650G Advanced Research

Earlier this year, Patek Philippe unveiled the limited-edition Aquanaut Travel Time Ref. 5650G, featuring the latest technology developed by its Advanced Research program. With its unusual aesthetics and impressive technological advances, it quickly became one of the most talked about watches at Baselworld. Today, we’re going hands-on with this incredible timepiece to learn more about what Patek Philippe is calling ‘two important innovations in the field of horological design’ and to see just how practical the watch is for everyday wear and use.

Patek Philippe Aquanaut Travel Time Ref. 5650G Advanced Research

Patek Philippe Advanced Research

For many people, Patek Philippe is a prestigious but conservative watch brand, focused primarily on traditional designs and historic complications. And while there is some truth in that description, the Geneva-based watch manufacturer is also highly innovative, constantly seeking to develop new technologies and improve on existing ones. Throughout the course of its 178-year history, the Maison has developed dozens of complications, displays and technical solutions, including the Gyromax balance patented in 1949/1951, which allows for the inertia of the balance to be adjusted without changing the active length of the hair-spring, and of course the invention of the annual calendar in 1996. It was this same pioneering spirit that led to the establishment of the Patek Philippe Advanced Research project in the early 2000s.

Ad – Scroll to continue with article

The turn of the century was a very fruitful time in watchmaking, with new technologies, and more particularly, new materials being discovered and developed. One material which caused significant debate and which is now widely used and accepted, is silicon. Observing the growing importance of this material and of the manufacturing processes linked to it (such as LIGA and DRIE technology), Patek Philippe moved quickly to get involved. With its independence ever a priority, the company chose to focus on close cooperation with independent development facilities such as the CSEM research laboratory and the Ecole Polytechnique Fédérale de Lausanne (Swiss Federal Institute of Technology Lausanne) that operates world-leading micromechanical and electronics research institutes in Neuchâtel. The researchers at Patek Philippe also often collaborate with colleagues at other respected manufactures, but the primary focus is on creating proprietary innovations.

Patek Philippe Advance Research 5250 Annual Calendar

The Ref. 5250 Annual Calendar Patek Philippe Advanced Research

The goal of the manufacture in establishing this project was to launch an avant-garde innovation program that enriched traditional development activities with research in the domains of “new materials,” “new manufacturing technologies,” and “new conceptual fundamentals.” The first big development was Silinvar®, a patented material based on monocrystalling silicon, which was developed jointly by Patek Philippe, Rolex, and the Swatch Group together with the CSEM in Neuchâtel, and unveiled in 2005. In addition to being virtually unaffected by temperatures ranging between -10°C and +60°C, this new material was extremely lightweight (only a third of the mass of steel, whilst being twice as hard), required no lubrication, was corrosion resistant and antimagnetic.

In that same year, the first escape wheel made of Silinvar® was unveiled, housed in the limited-edition Ref. 5250 Annual Calendar Patek Philippe Advanced Research. Aesthetically the watch was very classic looking, however, the sapphire exhibition caseback of the Ref. 5250 revealed a magnifier over the escape wheel and a specific bridge formation to allow for unobstructed views of this innovative escape wheel.

patek philippe advanced research Oscillomax

Since then, several notable innovations have followed from the Advanced Research project, including the Spiromax® balance spring made of Silinvar® (2006), the Pulsomax® escapement made of Silinvar® (2008), and the Oscillomax® ensemble (Pulsomax® escapement with GyromaxSi® balance and Spiromax® balance spring) (2011). As with the original unveiling of the Silinvar® escape wheel, each time a new technology was introduced, the manufacture launched special limited-edition timepieces that were the first to be endowed with one of the state-of-the-art solutions developed by the Patek Philippe Advanced Research venture. Each model featured a distinctly classic design aesthetic on the dial – consistent with what we’re used to from Patek Philippe – and a sapphire exhibition caseback for displaying the latest innovation in the movement.

The Aquanaut Travel Time Ref. 5650 continues this proud tradition of showcasing the latest technology from the Patek Philippe Advanced Research team in a limited-edition timepiece, albeit with some notable differences. For a start, it’s the first Advanced Research model not to be presented in a round case. It’s also the first that doesn’t feature an annual or perpetual calendar. Lastly, and more obviously, one of the technical innovations being presented is displayed boldly on the dial side, resulting in a watch that is far more futuristic-looking than we’re used to seeing from Patek. Before we get side-tracked with the aesthetics – we’ll come back to that later – let’s talk some more about these two innovations.

Patek Philippe Aquanaut Travel Time Ref. 5650G Advanced Research

Innovation. 1: A new Spiromax® balance spring with a patented terminal curve and an inner boss

It’s been just over a decade since Patek Philippe introduced the Spiromax® balance spring and ever since, the company has been working to make it even better. Following several years of R&D, the manufacture unveiled its new spring, which sees the original outer boss now paired with an inner boss. The outer boss, also referred to as the Patek Philippe terminal curve, improves the isochronism of the balance in all positions by assuring the adequately concentric expansion and contraction of the balance spring. Conversely, the inner boss offsets positional changes of the centre of gravity to assure the highest possible rate accuracy in vertical orientations. This means that the watch will not run slower or faster regardless of its orientation.

Patek Philippe Aquanaut Travel Time Ref. 5650G Advanced Research

As a result of these new developments, Patek Philippe announced that watches fitted with this new balance spring could be adjusted with a mean rate of -1 to +2 seconds per 24 hours. The Patek Philippe Seal imposes very stringent requirements on all the manufacture’s mechanical watches. The mean rate of movements with a diameter of more than 20 mm must range within -3 to +2 seconds per day. For Patek Philippe tourbillon timepieces, the tolerance is a strict 3 seconds per 24 hours, which means that models fitted with the new Spiromax® balance spring can match the rate accuracy of a Patek Philippe movement with a tourbillon. The objective is to gradually integrate the balance spring with this geometry into the current production schedule, demonstrating that the role of the Advanced Research Project is to benefit the entire Patek production and of course the eventual owners of the watches.

Innovation. 2:  Time zone corrections with compliant (flexible) mechanism in steel

Patek Philippe Aquanaut Travel Time Ref. 5650G Advanced Research

The second innovation, which is on display on the dial side of the watch, is a time zone correction system that uses a single flexible piece of steel to adjust the GMT indication forwards and backwards. The main part of this mechanism consists of four crossed leaf springs – two for each corrector button (one for the setting lever, one for the beak that advances the gear rim), each with defined pressure points. Each individual leaf spring is extremely thin, and they cross over each other at a distance of just 150 microns. Also manufactured in conventional horological steel, the development of the whole system required sophisticated computer simulations and over 500 hours of computer modelling. Cutting-edge, computer-programmable machines were then used to manufacture the components, which explains why this type of technological advancements using simple steel was not feasible before.

The result is really quite impressive. Before the development of this new part, the standard GMT mechanism was comprised of 37 individual parts. Now, it has been reduced down to just 12 parts, and perhaps more importantly, there are no gears or pivots. This means there is no mechanical play, no friction, and no arbor wear, which means completely lubricant-free functionality. It also means faster assembly – there are just 4 screws holding it all together – and a flatter silhouette (1.24 mm versus 1.45 mm). Excitingly, according to the brand, this first foray into “flexible mechanisms”, a new domain of research inspired by Professor Henein who holds a chair funded by Patek Philippe, has also opened-up totally new perspectives for numerous future applications in mechanical horology. In other words, watch this space.

The Aquanaut Travel Time Ref. 5650G

Patek Philippe Aquanaut Travel Time Ref. 5650G Advanced Research

So, what about the Aquanaut Travel Time Ref. 5650G itself, what’s it like on the wrist? And what about the unusual decision by Patek Philippe to have a semi-open worked dial to display the new time-zone mechanism? Well, for starters, on the wrist it is very comfortable. Presented in a 18K white-gold case measuring 40.8 mm in diameter and 11 mm thick, it’s not quite as polarizing as the press photos might suggest once you have it on. Like the Patek Philippe Aquanaut Jumbo 5168G, which was also unveiled at Baselworld, it has a gorgeous navy blue gradient dial with contrasting applied Arabic numerals and indices in white. As with the other Travel Time watches in the Patek Philippe collection, it displays the local time and date as well as a second time-zone, and a day/night indicator for both time zones. The pushers on the left-hand side of the case can be used to advance the time forwards or backwards by one hour when you travel, which also updates the day/night indicators and date as necessary.

Patek Philippe Aquanaut Travel Time Ref. 5650G Advanced Research

The big kicker of course, for hardcore Patek fan, in particular, is the partially open-worked dial, which puts the time-zone correction mechanism on full display. This was a bold decision by Patek as it’s a much more futuristic look from the brand than its buyers are used to but ultimately, I think it was the right one. Showcasing the technology in this way immediately allows the user to not only see it in action in real time but also to marvel at how apparently simple in construction it appears.

Patek Philippe Aquanaut Travel Time Ref. 5650G Advanced Research

The other thing to keep in mind is that this Patek Philippe we’re talking about, which means that all the surfaces of the new mechanical setting have been carefully finished and decorated according to Geneva watchmaking traditions. The visible surfaces are precision ground, the invisible undersides carefully brushed, and the insides of the leaf springs sandblasted. All edges are meticulously chamfered and polished (except, for functional reasons, those of the leaf springs). The surfaces around the bores for the mounting screws are circular grained. Under the loupe the level of detail is astonishing but even just looking at it with the naked eye it is visually quite attractive, albeit somewhat unexpected at first.

Patek Philippe Aquanaut Travel Time Ref. 5650G Advanced Research

Visible through the sapphire caseback is Patek’s automatic calibre 324 S C FUS, complete with the new Spiromax® balance spring. Measuring 31mm in diameter it beats at a steady 28,800vph and offers a max power reserve of 45 hours. Adorned with the Patek Philippe Seal, the movement is beautifully finished and is rated to -1/+2 seconds maximum daily rate deviation. Limited to just 500 pieces, the Patek Philippe Advanced Research Aquanaut Travel Time Ref. 5650G retails for 53,500 Euro. Aesthetically, it may not be to everyone’s taste but the importance of the technology it houses is undeniable. The big question, of course, is what’s coming next?

Patek Philippe Aquanaut Travel Time Ref. 5650G Advanced Research

Technical Specifications – Patek Philippe Advanced Research Aquanaut Travel Time Ref. 5650

  • Case: 40.8mm diameter x 11m thick – 18k white gold, polished and brushed – sapphire crystal on both sides – 120m water resistant
  • Movement: Caliber 324 S C FUS, in-house – Patek Philippe Seal – automatic – Spiromax® balance spring with a patented terminal curve and an inner boss – 4Hz frequency – 45h power reserve – hours, minutes, seconds, date, second time-zone, day/night indicator
  • Strap: Night blue composite strap embossed with same checkerboard pattern as dial – double-security fold-over clasp in 18K white gold
  • Price: 53,500 Euro – Limited Edition of 500 pieces

5 responses

  1. This looks appealing, unfortunately I have 1 more child to put through Uni 🙁

  2. Would I love to own a Patek Phillipe of course I would, could I afford to buy one, no! (Unless someone’s willing to give me one?). That’s not going to happen. So I continue to buy lower priced watches, and you know, even they still work.

  3. “The big kicker of course, for hardcore Patek fan, in particular, is the partially open-worked dial, which puts the time-zone correction mechanism on full display.”

    The timepiece appears “undone” in a word. Appearance unbalanced.
    At first glance, a woman doesn’t display her inner self.

  4. Great article!
    I am just getting interested in watches and there seem to be a ton of watches out there!
    I am considering buying a new watch but considering my very limited watch knowledge, I thought I’d ask you for some advise.
    A watch that caught my eye was this one: but I am not sure it’s good? So I thought I’d ask for your advise.
    What do you think?
    Thank you in advance

  5. Dial looks like half cyborg, the watch having part of it’s face missing.Not pretty, especially at the price. I’ll just have the regular Aquanaut please, Don’t understand why anyone would pay more for this.If I’m buying Patek I expect elegance not something that looks like it’s from Terminator 6 or whatever number they are up to. I’m sure it’s a fine watch but it’s definitely the ugly version.

Leave a Reply