Feature: How The World’s Thinnest Watch Was Made (Part 1)

Creating the world’s thinnest watch doesn’t happen overnight. It doesn’t happen in a month, or a year, or even a decade. It takes several lifetimes of expertise, development, successes, failures—all to get to this: the Piaget Altiplano Ultimate Concept. This watch is 2mm thick. Let’s find out how it was done.

From the perspective of an outsider, the challenges faced by a record holder are rarely observed. To you and me, the announcement of Piaget’s concept to build the world’s thinnest watch may have come out of the blue, but for Piaget itself, it’s been a journey of constant learning.

It’s an old brand, manufacturing watches and movements since 1874, and one of the advantages of making your own parts is the benefit of having complete control over the design. When you buy someone else’s movement, you’re stuck with what you get, you have to make compromises; when you build it yourself, you can push in whatever way you want to.

For Piaget, that was with slenderness. A wristwatch has, for much of its life, been a measure of a man’s decorum, his refinement—only from the 1970s did it become fashionable to wear one as a statement. Before that, it was a case of being neither seen nor heard, except only on the occasions where it was required.

At the 1957 Basel Fair, a crowd had formed around a small stand—I mean, all the stands were small back then, when it was a trade fair and not a circus—to chance a glimpse at what was to become the marvel of the entire event. At just 2mm, Piaget had created the thinnest calibre in the world, the 9P, a movement that was as pivotal back then as the change of Netflix from physical format to digital streaming.

Three years later, and with a bigger stand this time, Piaget did it again, announcing the calibre 12P, a 2.3mm movement that also somehow included automatic winding as well. How did they do it? By using a micro rotor, a smaller, more compact version of a full-size rotor that typically spans the entire diameter of a movement, Piaget was able to package this fully functioning mechanism into an extremely small space.

To establish just how incredible that movement was, compare it to the modern Altiplano 1205P. An automatic watch, featuring a micro rotor like the calibre 12P, it’s 0.7mm thicker than its older counterpart. Make no mistake, the 1205P is a staggeringly impressive movement and built upon many of the same principles—it’s just not as impressive as the one from the sixties.

But why? How did Piaget go from leading by a country mile, to failing to meet the standards of its own achievements? Between 1960 and 1980, the need for ultra-thin movements—and in fact any mechanical movement—all but disappeared. Quartz watches meant Piaget needed to find a new way to survive, and its increasingly popular jewellery was a great way to do it. Sadly, that meant progress on these physics-defying masterpieces hit a brick wall—and there it stayed for over half a century.

By 2014, Piaget’s 140th anniversary, the watchmaking scene had changed yet again. There was a hunger for mechanical complexity and ingenuity, like there had been back in the fifties and sixties. This reawakening came later than might perhaps be imagined, the turn of the millennium only just starting to pique the interest of modernist watchmakers like Urwerk and MB&F.

For a long time between, customers were happy to have anything going on inside their watches, but as awareness increased and the passion started to rekindle, manufacturers soon started to learn that a dressed-up ETA was no longer going to do the trick. This was a bit of a pain for companies that didn’t have the capability to manufacturer their own movements, and is a big part in why watch prices have gone up so much over the last few decades.

At Piaget HQ, meanwhile, a strokey beard meeting was had, and it was determined that this new interest in mechanical watches gave the brand the perfect opportunity to revive its pursuit of the ultra-thin watch. And it wasn’t to be just a thin calibre, but the thinnest calibre, one that took a complete, ground-up re-evaluation of how a watch is manufactured.

At 3.65mm, the Altiplano Ultimate 900P, the spiritual successor of that original 9P, may not sound too impressive—until it is revealed that this is the thickness not just of the movement, but the entire watch. And it’s no accident that the watch shares its name with the calibre inside, because for the first time ever, they were one and the same thing.

Let me explain. Where most watches have a movement housed inside a case that’s made up of a sandwich of the case back, case middle and bezel, the 900P did not. Instead it used a monobloc, a singular piece of metal that served all those functions—and one more. In the journey to making the thinnest watch ever, the watchmakers at Piaget realised something—the watch and the movement could become one homogenised part.

This meant that all the jewels and screw threads usually found in the baseplate—that is, the structural foundation of a movement—were manufactured straight into the case back instead. The rest of the calibre 900P was built straight on top of it, saving precious millimetres in the quest for thinness. Like the automatic rotor on the 12P, the dial was recessed into the movement, offering more space for the bridges. Wheels were shaved down to thicknesses less than a human hair. The mainspring barrel, attached only on one side, was suspended to eke out yet more slenderness. It’s all as thick as the thickest part—the balance wheel.

But Piaget wasn’t done yet. In 2017, to mark the 60th anniversary of the Altiplano, the 910P was created, an automatic version of the incredible 900P. At 4.3mm thick, the Altiplano Ultimate Automatic 910P smashed the record for the thinnest automatic watch using the same monobloc principle of the 900P, but now with a slender peripheral rotor winding the mainspring. Piaget was finally back where it belonged, making the thinnest watches ever made.

But this was still not enough. There were still microns to spare, wheels to shave, springs to thin. The challenges to do so, however, were far greater than the watchmakers at Piaget could have ever foreseen. In pursuit of the dream of making an entire watch as thin as that 1957 calibre 9P, the team went through hell and back. It very nearly didn’t happen on multiple occasions, demanding the utmost expertise from every single person on the project. Next time we’re going to find out exactly how Piaget managed to make the thinnest watch in the world, the Altiplano Ultimate Concept.

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