A growing, albeit still relatively small, number of luxury watchmakers have embraced the challenges of using sapphire as a material not only for the crystals covering their watches’ dials, but for entire cases as well (a handful of these transparent timepieces are represented here) — but it is Hublot that is clearly (you should pardon the pun) leading the charge. At Baselworld 2018, the Swiss brand known for its bold forays into unconventional materials and envelope-pushing technology took the still-exclusive category to a new level with the introduction of the Big Bang Sapphire Tourbillon, which boasts not only a crystal-clear case but a see-through skeletonized movement as well.
In addition to the transparent sapphire case and crystal, the resin dial, and the matching translucent strap made of structured lined rubber, the Big Bang Sapphire Tourbillon also boasts a painstakingly skeletonized version of Hublot’s in-house HUB6016 manual-winding tourbillon movement — yes, the same five-day-power-reserve caliber we’ve seen in previous Hublot tourbillon models like the Big Bang Tourbillon Power Reserve 5 Days Titanium, but here with one big difference: the components, except for a few metal gears, are also see-through, constructed of high-tech polycarbonate materials. At center stage is the bridge supporting the tourbillon cage, which, like the majority of the exterior parts, is made from a strip of nigh-indestructible sapphire. The effect is somewhat mesmerizing, with the clear mechanical parts seemingly floating inside the case while the tourbillon performs its balletic motions.
Like its predecessor from 2016, the Big Bang Unico Sapphire, this watch’s 45-mm case is milled from blocks of solid sapphire, a material nearly as hard and as scratch-resistant as diamond and, consquently, extremely difficult to machine. The few non-sapphire elements in the case include the six H-shaped titanium screws that hold fast the bezel to the case body, the metal crown, and elements of the lugs and buckle, which is also titanium. The hands on the dial are rhodium-plated brass, and both they and the large Arabic hour numerals have been treated with Super-LumiNova.
As one would expect, the case is thick — 14.26 mm — and offers only modest water resistance, at 30 meters. The movement has been stripped down to a relatively sparse 175 components, including 25 jewels, and beats at 21,600 vph. The movement’s touted five-day power reserve (actually 115 hours, which translates to 4.79 days, but really, who’s counting at this point?) is displayed on the dial as well; again, transparency in all areas is the watchword here.
The Hublot Big Bang Sapphire Tourbillon is limited to 99 pieces and priced at $148,000.