Ulysse Nardin Executive Skeleton Tourbillon Titanium — Skeletonised Dial | Ref. 1713-139

The Executive Skeleton Tourbillon positions itself at the intersection of Ulysse Nardin's avant-garde architectural ambitions and the practical requirements of a wearable grand complication. The 45mm grade-5 titanium case houses Caliber UN-171, a manually wound flying tourbillon movement whose 170-hour power reserve — just over seven days — is made possible by the same silicon escapement technology that runs through the Ulysse Nardin InnoVision research programme. That programme, which has produced silicon balance springs, silicon escapement wheels, and the Constant Anchor Escapement, represents the most sustained commitment to advanced escapement materials of any Swiss manufacture, and its benefits accumulate most dramatically in the flying tourbillon: reduced friction means less energy loss per oscillation, more efficient mainspring discharge, and a power reserve that exceeds comparable titanium tourbillons from competing manufactures by a significant margin.

Caliber UN-171's skeletonisation is structural rather than merely decorative: the movement's bridges and plates have been reduced to their essential geometries, leaving the tourbillon cage, the wheel train, and the going barrel visible from the dial side in a display of mechanical transparency that the Executive collection's design language demands. The ceramic bezel provides both scratch resistance and a material contrast with the titanium case — its polished black surface absorbing light where the case's satin-brushed surfaces scatter it, creating a layered visual depth. The screw-down security crown maintains water resistance throughout the demanding 30-metre rating that is appropriate for a grand complication.

Grade-5 titanium, with its exceptional strength-to-weight ratio and natural resistance to both corrosion and skin sensitivity, makes the Executive Skeleton Tourbillon's 45mm dimensions wearable in a way that steel could not achieve at equivalent mass. The carbon-structured leather strap with folding buckle continues the high-performance materials dialogue from case to wrist. At its price point, the combination of a genuine flying tourbillon, 170-hour silicon-enhanced power reserve, and titanium case construction from one of Swiss watchmaking's most technically distinguished manufactures represents a compelling proposition for the serious complication collector.