We’re all familiar with skeleton watches, but this Richard Mille tourbillon timepiece is more accurately described as a skull watch, hence its name: the Tourbillon RM 052 Skull. The watch, which made its debut at SIHH 2012, was released in a limited edition of 21 pieces — 15 in titanium and six unique pieces set in rose or white gold.
The watch’s signature feature, of course, is its striking, skull-shaped baseplate made of grade 5 titanium. However, it’s not just a clever design element but also integrated into the movement: the upper and lower “jaws” hold the ruby of the tourbillon cage, and the back of the skull is also the movement’s center bridge. The four bridges that connect the movement to the case are arranged in a “skull-and-crossbones” pattern inspired by flags from pirate ships. The baseplate and bridges (skeletonized, naturally) have been subjected to rigorous testing to ensure a high level of strength and rigidity. The titanium alloy used for them is also used frequently in the aerospace, automobile and aeronautical industries due to its high corrosion-resistance.
Among the other technical touches are a free-sprung balance, which provides protection from shocks and allows for more precise adjustments; a fast-rotating barrel (six hours per revolution rather than 7.5 hours), which helps increase performance by diminishing mainspring cohesion; a barrel pawl with progressive recoil, which helps in distributing the mainspring’s internal tension; and spline screws made of grade 5 titanium, used for the bridges, which permit better torque control during assembly. The tripartite case requires 255 machining steps, including 86 stamping operations. Richard Mille has made the big case lighter by creating openings in the bezel and caseback. The case also uses spline screws in titanium for greater torque control, and has a torque-limiting crown, an additional security feature to prevent accidental overwinding.
Be prepared to pay a premium for this horological headbone: the retail price is $500,000.
Movement: Caliber RM052, manual-winding tourbillon. Dimensions = 32.8 x 30.9 mm, 10.9 mm thick. 19 jewels. Glucydur balance wheel with four setting screws. Frequency = 21,600 vph (3 Hz). Elinvar by Nivarox balance spring. Kif Elastor KE shock protection. Finishing includes hand-polished beveling, micro-blasted milled sections, and drawn or polished outer faces. Power reserve = 48 hours.
Functions: hours, minutes, tourbillon.
Case: Tripartite titanium case, assembled with 20 spline screws in grade 5 titanium. Abrasion-resistant washers in 316L stainless steel. Dimensions = 42.7 mm x 50 mm. Water-resistance to 50 meters ensured by two O-ring seals. Upper flange in carbon, lower flange in grade 5 titanium with DLC coating. Sapphire crystal front and back with anti-glare coating.
This article was originally published on March 1, 2012, and has been updated.