Just when you thought it wouldn’t be possible for jeweler and watchmaker Harry Winston to surpass its previous tourbillon wristwatches, the American house continues to push – and break – the limits of traditional watchmaking theory with its seventh edition: the Histoire de Tourbillon 7. The Swatch Group-owned brand drew a lot of attention with this timepiece at BaselWorld 2016 and we definitely think it is one of the star pieces of the year.

The Histoire de Tourbillon model – as the name suggests – is a timepiece series focused on tourbillons. Harry Winston has explored several variations on this theme; last year’s iteration saw a tri-axial tourbillon and previously, a double tourbillon. This year, the watchmaker explores the bi-axial tourbillon – with a twist in that there’s now two, both identical. Since the bi-axial tourbillons are both identical, let’s look at how one works. First of all, the term bi-axial tourbillon simply means that there are two cages here instead of the usual one and that both rotate on different axes. There is still just one balance, hairspring, pallet fork and escape wheel.

In the case of the Harry Winston Histoire de Tourbillon 7, the cage that houses the balance wheel – angled at 30 degrees – completes a rotation in 45 seconds. This assembly is in turn housed in a second cage that completes a rotation in 75 seconds. The two identical bi-axial tourbillons are then regulated by a spherical differential to create an average. Theoretically, if two tourbillons are better than one, the differential would result in the averaging out of two exceptional time keeping mechanisms working double-time to eliminate errors of rate. At the bottom of the dial, a power reserve indicator in roll form fills the little gap left by the dual tourbillons and hour and minute section.

Facade-wise, the Harry Winston Histoire de Tourbillon 7’s 18k white gold case houses a rectangular dial with an anodized aluminum design. Its 50mm diameter and 17mm thickness means this watch is a big fella but that is the trade-off for having angled bi-axial tourbillons in action. The horological masterpiece requires hundreds of hours of delicate artisanal expertise of hundreds of hours. In a limited edition of 20, the watch is available in either a red or anthracite version.

Specs:

• Dimensions: 50mm
• Functions: Off-center hours and minutes, display of power reserve on roll
• Power Reserve: 55 hours
• Movement: Manual-winding calibre HW4502, bottom plate in satin-finish and stippled titanium, bridges in titanium, double Côtes de Genève, tourbillon bridges polished and beveled by hand
• Material: 18K white gold
• Water Resistance: 30 meters
• Strap: Alligator leather