3 Standout Complicated Watches from Hong Kong “Watches & Wonders” Fair Written byMark BernardoOctober 10, 2013 Vacheron Constantin introduced several new models at Watches and Wonders, including the new Patrimony Traditionnelle 14-Day Tourbillon (click here for our article); the most complicated of the selection, despite its elegantly clean exterior, is the Patrimony Contemporaine Ultra-Thin Calibre 1731, which Vacheron says is both the world’s thinnest minute repeater watch, at just 8.09 mm thick; and the thinnest minute repeater movement, at just 3.9 mm thick. Calibre 1731, named for the birth year of brand founder Jean-Marc Vacheron, is only slightly thicker than Vacheron Constantin’s earlier ultra-thin repeater movement from 2009 (which was a mere 3.28 mm thick), due to the addition of a longer, 65-hour power reserve. It also incorporates the “flying strike governor” developed for the company’s 2755 movement in 2007, designed to steady the rate at which the repeater’s hammer’s strike the gongs. This device bears Vacheron Constantin’s Maltese Cross emblem, even though it is not visible to the wearer. To ensure as clear a sound as possible for the chimes, the gongs are stacked, rather than placed side by side, and connected to the case middle. In this way, the case is made to be as one with the movement; the case is constructed without joints so that it and the gongs can interact — metal against metal — for an ideal amplitude of sound. The pebble-shaped case, in 18k rose gold, is inspired by an ultra-thin Vacheron Constantin watch from 1955, which was resurrected in 2004 as the basis of the Patrimony Contemporaine collection. The bezel and sapphire crystal are both curved, and the understated dial has a beaded minute circle, baton-shaped hands and alternating triangle and baton-shaped applied hour markers made of rose gold. The off-center small-seconds subdial at 8 o’clock is a first for the Patrimony Contemporaine line. The movement boasts various decorative finishes, including a circular-grained mainplate and bridges embellished with côtes de Genève. Each watch, which comes on a brown alligator strap with a rose-gold, Maltese Cross-shaped buckle, requires three to six months — and more than 1,200 tools — for a single watchmaker to assemble and adjust. Each is also certified with the Geneva Hallmark. For our recent “Watch Insider” article on new IWC watches for the Watches and Wonders salon, click here.