Piaget
The Pursuit of Wearing Thin
Piaget
The Pursuit of Wearing Thin
In fact, all three contenders can be said to represent a new generation of ultra-thin watches where performance takes greater precedence than ever before. All of them, for instance, operate at 4Hz, as opposed to the more common 3Hz frequency practiced in this sector of watchmaking as a consequence of a thinner, weaker mainspring as well as to preserve power reserve. Additionally, the use of unconventional materials such as titanium and M64BC offer higher structural rigidity while simultaneously reducing the weight of the watch. Above and beyond all records, each watch has introduced its own unique and at times highly imaginative solutions to saving precious micro-millimetres, making technical comparisons, apart from sheer numbers, far from straightforward.
Piaget Altiplano Ultimate Concept
Additionally, the barrel has an open design revealing its state of wind in a “hanging” construction. However, it is supported on its periphery by ceramic ball bearings in addition to being supported on its bottom pivot. In the same vein, the balance assembly – its hairspring, staff, cock, shock absorber jewel cap – which determines the height of every movement, had to be rethought. For the first time in a watch, the balance is not secured in place by a bridge or a cock. Instead, the shaft of the balance is supported on ball bearings integrated in the main plate. This reduces the height of the movement while eliminating the need for shock absorbers. And as a result of removing the balance cock, the hairspring had to be attached to a circular bridge screwed to the main plate, hence is located under the balance wheel. Consequently, with such a design, the balance had to be free-sprung.
Thanks to the numerous unusual solutions, the Piaget Altiplano Ultimate Concept went unassailed for three years.
Bvlgari Octo Finissimo Ultra
The differential is powered by an additional wheel in the gear train driven directly by the barrel. There are thus five wheels in the wheel train inclusive of the barrel, which results in a counter-clockwise rotation of the fifth wheel, like in the Piaget AUC. While the AUC does away with a seconds indication completely, the Ultra has its seconds chapter ring directly printed on the fifth wheel and requires a separate pointer printed on the bridge below so the seconds can be read more intuitively as it is rotating backwards.
The volume of the movement has been thoroughly optimized, with the barrel occupying half of the movement’s diameter, enabling it to deliver a respectable power reserve of 50 hours on a 4Hz escapement. It has a floating or hanging construction, with its arbour supported only on its bottom end, and is topped by a ratchet wheel, on which a QR code providing access to an NFT artwork is engraved.
While the bracelet, bezel and case band of the Ultra are made of titanium, the case back accommodating the moving parts is made of tungsten carbide, a metal that is even harder than titanium. The sapphire crystal measures just 0.3mm thick, making it prone to flexing when pushed, potentially touching the hands. Thus, a pair of silicon bumpers are installed under the dial to prevent the crystal from reaching the components.
Richard Mille RM UP-01 Ferrari
While it relies on some textbook solutions such as distributing the gears across a single plane, the painfully thin movement has been engineered to withstand accelerations of over 5,000 Gs, which is a hundred times more than a car crash. The movement is made of titanium which offers substantial rigidity. In contrast to its predecessors, the moving parts in the movement is further fortified by an upper titanium plate as well as a case back. Held together by 13 screws, the top plate sits flush with the case back with the main plate sandwiched in between.
The calibre benefits from its particularly wide dimensions. All the components are spread out comfortably with minimal stacking. The motion works are driven by the barrel via an auxiliary train, and in turn, the minute and hour wheels drive a pair of discs respectively for the time display. The barrel is extremely thin and is fitted with an exceptionally fine mainspring. Thus, the floating barrel had to be secured to the base plate by rollers. The winding wheels as well as auxiliary train occupies the right expanse of the movement while the gear train is relegated to the left.
While ultra-thin watchmaking is an ongoing battleground with virtually no end in sight, the RM UP-01’s robustness and shock resistance, particularly in this sector of micromechanics, represent a different level of achievement that is tough to beat, at least not any time soon.