For the seventh consecutive year, Harry Winston is unveiling it interpretation of contemporary haute horlogerie. Featuring two biaxial tourbillons and a creative, complex, and graphic aesthetic, the Histoire de Tourbillon 7 takes another step forward in the world of high-end watchmaking. While I thought the recent Opus 14 missed the mark a bit in terms of its aesthetic, this piece is exceptional in its design. Full details, below.
Having already explored other complex variations on the tourbillon – biaxial, triaxial, double or coupled with a carrousel – Harry Winston has with the Histoire de Tourbillon 7 opted to feature two biaxial tourbillons, which I would say are boldly presented. But let’s start at the right side of the dial. It features a pyramid-cut reading area that houses the hour and minute hands. It is surrounded by indexable inserts that form a tilted three-dimensional hour circle, further extended by a long strip in either red aluminum or anthracite (depending on the version) which extends out and to the left to frame the two biaxial tourbillons.
I’ll rely mostly on Harry Winston’s words to describe the construction and intricacies of the double bi-axial toubillons:
The first tourbillon cage moves into a second cage and both turn on a different axis. The tourbillon’s first cage completes its rotation in 45 seconds, with a balance wheel that is tilted 30 degrees. The second tourbillon and the balance wheel rotate once per 75 seconds and its two cages are nested one inside the other. (Ed.’s note: Essentially the interior tourbillon cages have a 45 second rotation while the exterior cages have a 75 second rotation.)
The two tourbillons, though identical in structure, frequency and speed, have their own behavior, due to their different positions in space. To reconcile the operation of these two rotating time-regulating bodies, the Histoire de Tourbillon 7 uses a spherical differential that optimizes performance, by connecting the two tourbillons – which have subtly different operations – and creating an average. The Histoire de Tourbillon 7 leverages the accuracy of two exceptional tourbillons and extracts the best performance.
At the bottom of the dial is a rolling/cylindrical power reserve indicator (up to 55 hours).
The Caliber HW4502 is obiously quite complex — 507 components in total, with 117 components for each biaxial tourbillon, and 84 jewels. It operates at a frequency of 3 Hz (21,600 vph) and requires manual winding. The bottom plate and bridges are made of titanium.
What is not apparent from the images is the rather large size of this watch. The caliber itself is very large, measuring in at 43.5mm in diameter. This then carries forth to the 18K white gold case, which measures in at a whopping 50.9mm in diameter! And thanks to the space required by the tourbillons, it is also on the thicker side, at 17.9mm. Of course crown guard is in the form of the iconic Harry Winston logo – three arches that represent the entrance to the House’s legendary Fifth Avenue flagship salon in New York – a Harry Winston signature.
All said and done, the Histoire de Tourbillon 7 is no doubt an extraordinary timepiece. And like its six predecessors, production will be limited to only 20 timepieces in total: 10 pieces for the red version and 10 pieces for the anthracite version.
Movement Technical Specification List
Type Mechanical, manual
– Diameter 43.5 mm
– Height: 8.65 mm
Number of components 507, including 117 for each biaxial tourbillon
Number of jewels 84
– Two biaxial tourbillons connected by a spherical differential
– Interior cages: 45 second rotation
– Exterior cages: 75 second rotation
– Total weight of each tourbillon: 0.76 g
Barrels Three rapid rotation coaxial barrels
Power reserve Up to 55 hours
Frequency 21,600 vibrations/hour (3Hz)
Balance springs Phillips terminal curve and Geneva-style stud
Balance wheels 30° inclination, variable inertia, gold adjustment screw
Finishes Bottom plate in satin-finish and stippled titanium, bridges in titanium, double Côtes de Genève, tourbillon bridges polished and beveled by hand