Vacheron Constantin introduced the Overseas Tourbillon Skeleton at this year’s Watches & Wonders. Available in platinum and rose gold, the haute horlogerie timepiece does not only represent top-notch craftsmanship and technical prowess, but also mark some premieres for the Geneva-based manufacture. Firstly, it introduces the tourbillon complication to the Overseas collection. Secondly, it is also the first Vacheron Constantin watch made entirely of Grade 5 titanium, including the bezel and crown. Last but not least, it is equipped with a new in-house regulating organ featuring a balance-spring with a Breguet overcoil. There are only a handful of manufacturers that can pride themselves with producing their own balance-spring.

Vacheron Constantin embarks on a new journey with this Overseas tourbillon skeleton model, a first in this collection that debuted in 1996. The skeletonization work carried out on the selfwinding Calibre 2160 which offers a three-day power reserve has enabled not only a 20% reduction in the movement’s weight but also a complete rethinking of its architecture. Its curvature is thus very slender, at barely 5.65 mm thick – a real technical feat considering the requirements linked to the integration of a tourbillon carriage.

This thinness is notably due to the choice of a peripheral gold oscillating weight, which also enables a completely clear view of the rear of the movement. The work done on the baseplate and the four bridges can be fully admired, with the NAC (N-acetylcysteine) surface treatment applied by electrolysis conferring an anthracite grey tint. This contemporary touch blends beautifully with the classic haute horlogerie finishes in the form of hand-drawn flanks and hand-chamfering with polished bevels to accentuate the light playing across the components. The mainplate and bridges are also delicately decorated to create a finish of very fine, perfectly horizontal grooves.

The same NAC surface treatment can be found on the barrel, of which the drum and cover have been entirely openworked, creating a compass rose shape on the dial side – another original feature of Caliber 2160 SQ. To complete the openworking of this 186-component movement, the wheels have also been made lighter, while the tourbillon is held by a rounded-off upper bridge.

The tourbillon regulator rotating once per minute operates at a rate of 18,000 vibrations per hour (2.5 Hz) and serves as a small seconds indicator via four screws used to secure the carriage. It is grey on the pink gold version and flame-blued on the titanium version.

For this new calibre, Vacheron Constantin’s watchmakers have also redesigned the regulating organ housed in the tourbillon carriage coupled with the escapement. A new balance-spring was designed in-house, equipped with a Breguet overcoil (terminal curve). By folding the outer spring coil towards the center, outside its horizontal plane, this arrangement forces a flat development of the spring, thus ensuring enhanced isochronism.

The sapphire crystal serving as the dial reveals all the details of the calibre, like a horological anatomy taking shape with each component. The hour-markers secured to this crystal are in rhodium-plated 18K 5N pink gold or 18K white gold, depending on the model. The same noble metals are used for the hands which, like the hour-markers, are coated with Super-LumiNova ensuring perfect night-time visibility. The dial ring is available in black lacquered 18K 5N pink gold or in blue PVD-treated 18K white gold.

Particular care has been devoted to the finishing of the case and bracelet. The bezel ring is circular satin-brushed on the 18K 5N pink gold version and sandblasted on the Grade 5 titanium iteration. The case and bracelet of both models are vertically satin-brushed with polished angles on the bracelet links, whose shape is inspired by Vacheron Constantin’s Maltese Cross emblem.

Both watches have a diameter of 42.5mm and a height of 10.39mm  and feature the Overseas collection specific interchangeable strap system. They come with two straps in calfskin and rubber: black with two 18K 5N pink gold pin buckles for the gold model; and blue with an interchangeable titanium folding clasp for the titanium model. Pricing is yet to be publicly announced.

To learn more, visit Vacheron Constantin, here.