Ulysse Nardin’s most riveting release from 2020 was the Blast, introduced at last summer’s Geneva Watch Days, which married a skeletonized self-winding tourbillon caliber with an avant-garde, stealth-aircraft-inspired case configuration. At Watches & Wonders this week, the Le Locle-based brand took the Blast to its next ? and thus far highest ? level of high-horology complication, with the launch of the Blast Hourstriker, a new and innovative take on the classical chiming watch.

The Hourstriker incorporates the groundbreaking technology that UN developed in cooperation with the French audio technology firm Devialet (and debuted in 2019s Classico Hourstriker Phantom) and adapts it to the Blast’s unconventional architecture. The striking mechanism itself is, in fact, unconventional as compared to the traditional type, in which hammers strike a wire gong wrapped around the movement to send sound waves emanating outward, which are then largely muffled by the watch?s exterior materials. In creating Caliber UN-621 ? its first in-house, self-winding striking movement, which powers this new timepiece ? Ulysse Nardin set out to both improve the sound-quality-to-output ration and make the chiming mechanism visible on the dial side.  The movement hosts a flying tourbillon, a variable-inertia balance wheel, and a hairspring, anchor and escape wheel all made of friction-resistant silicon. Sleeker than previous UN Calibers, it uses the ?X? motif of recent UN...