The HW4701 caliber of Histoire de Tourbillon 6 is the most complex in the series. It combines two independent hour indications: one regulated by a tri-axial tourbillon and the other by a karussel.
The Histoire de Tourbillon 6 movement is composed of two independent parts. Hours and minutes are displayed on one side, regulated by the tri-axial tourbillon. They are recognizable by their color coding – orange against a gray background. The right side of the watch is distinguished by its blue hands and markings against a black backdrop. It features a dial with hands that can be started, stopped and reset at will. A blue ceramic pusher at 2 o’clock allows this watch to display the elapsed hours and minutes like a chronograph. This unique and versatile function also drives a dual-time display that may be adjusted via the 3 o’clock crown.
The tri-axial tourbillon is supremely exclusive. The first cage carries the balance wheel and performs one turn every 45 seconds. It rotates inside a second cage, which spins in 75 seconds along its vertical axis. This ensemble is set in motion inside a third, spherical cage, which completes its own revolution in 300 seconds. The latter is the cage featuring the orange seconds hand, visible beneath a sapphire crystal dome that offers a fascinating view of the three-dimensional ballet of time. Meanwhile, the karussel performs a 30-second rotation.
The varying rotation angles and speeds of the tourbillon and karussel counteract the detrimental effects of gravity. Precision is further enhanced by the fast-rotating twin barrels, boasting an exceptionally regular torque.
Caliber HW4701 is made up of 683 parts. Its tri-axial tourbillon alone requires 141 parts and weighs a mere 1.85 grams. This voluminous graphic structure is visible beneath four sapphire crystals, all distinguished by convex and complex shapes.
The complication that makes the Histoire de Tourbillon 6 unique is a subtle and inconspicuous one. If need be, the karrusel positioned at 1 o’clock can remain idle. When started, it acts as the regulator for the independent part of the HW4701 movement, occupying the right side. It is stopped by default, but starts running when the pusher, located on the caseband is pressed. The specific construction of the karussel means that its balance wheel and its cage are simultaneously linked to the movement’s energy source. Even when halted, they are under constant tension and when released, instantly accelerate to cruising speed. This extremely rare karussel, with a 30-second rotation, operates at high speed in order to occupy a maximized number of positions in space.
With this regulator, time displays can be personalized. The movement on the right side is akin to a monopusher chronograph and replicates that function. Its hands, however, are adjustable via a crown at 3 o’clock. Therefore, they can provide a dual-time display that is accurate to the nearest minute.
Despite its exceptional dimensions, 64 mm from crown to crown, Histoire de Tourbillon 6 has a comfortable fit. The mainplate and bridges are made of titanium, a metal chosen for its light weight. The case is fitted with ergonomic lugs.
The case is crafted using a white gold alloy with a high palladium content, giving it an attractive glow and radiating a matte sheen. It is entirely hand-beveled and sandblasted. The rendering is both sophisticated and striking, and entirely in harmony with the technical nature of the timepiece.
Only 20 pieces of the Histoire de Tourbillon will be produced.
