Harry Winston (who was recently acquired by the Swatch Group) has just released a preview of the Histoire de Tourbillon 4. It is the fourth in a series of five highly complicated tourbillon watches, and it will be officially launched at Baselworld this April. The highlight of the Historie de Tourbillon is a tri-axial tourbillon — which I will explain below.
The Histoire de Tourbillon 4 is presented in a massive 47 mm by 21.7 mm 18K polished white gold case with a DLC treated Zalium case band, arches, lugs and tourbillon bezel (Harry Winston invented Zalium and has a patent on it). The dial is protected by a sapphire crystal with a curved sapphire crystal on the tourbillon. The Harry Winston logo is engraved on the tourbillon bezel.
The dial is three dimensional, with apertures on the movement. It has a black galvanic flange and appliques. Black and silver applied hours, minutes and power-reserve indicator with horizontal satin-brushed counters. In the center of the hours counter is an engraved an “HW” emerald logo. Indexes are filled with black, grey, orange and blue varnish.
The H4 is powered by caliber HW4501, the manually wound movement consists of 345 components, 59 of which are jewels. It runs at 21,600 vph (3Hz). Rapid rotating twin barrels in series (1 turn in 3.2 hours) ensure power for up to 50-hours. The balance spring has a Phillips curve with a Geneva-type stud. Variable-inertia balance fitted with 18 gold adjustment screws.
The mainplate is in titanium and has been micro-blasted, hand-chamfered and PVD treated. The bridges are in titanium and are polished, hand-chamfered, PVD treated. The intermediate carriage bridge is in polished gold and is hand-chamfered. The Carriage pillars are in titanium, and feature circular graining and a PVD treatment.
Functions include hours, minutes and a 300 second indication on the tourbillon, as well as a power-reserve indicator.
The tri-axial tourbillon, as the name would suggest, is a single tourbillon on three axis which simultaneously rotate via internal, intermediate and external carriages. The internal carriage contains the balance spring and escapement pinion, rotating completely every 45 seconds. The intermediate carriage rotates every 75 seconds. The external carriage rotates every 300 seconds.
Hand-sewn black alligator leather strap with 18K gold buckle. Water-resistant 30 meters. Limited edition of 20 pieces.
The tourbillon is designed to offset the affects of gravity in order to make the watch more accurate. Creating a piece where three different cages are rotating at three different angles and three different speeds, is extremely complicated. Moreover, watching the tourbillon in motion is surely a visual treat. But, is it any more accurate? (Ref. HCOMDT47WZ001)