IWC Portuguese Yacht Club Chronograph 43.5 Silver (IW3905-02)

A new tourbillon classic takes its place in the Portuguese family, with a hand-wound pocket watch movement - tradition in its purest form. The Portuguese Tourbillon Hand- Wound is an horological gem and a tribute to the founder of the company, F. A. Jones.
Beware of a b whirlwind approaching from 270 degrees West. This is not a weather alert, but the briefest possible description of the new Portuguese Tourbillon Hand-Wound. Tourbillon translates as whirlwind. The escapement in the rotating carriage is also clearly visible on the dial at "9 o'clock", in nautical parlance at 270 degrees West. The Portuguese Tourbillon Hand- Wound follows in the wake of the limited-edition Portuguese Regulateur Tourbillon, itself dedicated to devotees of earlier observatory watches, with its hour display in a separate subdial.
The new Portuguese Tourbillon Hand-Wound presents the familiar face of the Portuguese with its elegant feuille hands and a chapter ring in the railway-track style. Any appearance by the Portuguese Tourbillon Hand-Wound always attracts attention: initially, it projects only a little from beneath the cuff of the wearer's shirt. Yet it is unmistakeably a Portuguese, a refined icon, with the sweeping signature of the American founder of the company, F. A. Jones, on the dial. The flying minute tourbillon only emerges with the final third of the dial and reveals its affiliation to the horological nobility. The tourbillon has always been perceived as a statement of expertise and exquisite horological taste. One simply never tires of marvelling at this precision mechanical performance.
The allusion to continuing tradition is also embodied in the watchmaking technology of the Portuguese Tourbillon Hand-Wound. The mechanical IWC-manufactured 98900-calibre movement can be observed through the seethrough sapphire-glass back. It lies at the top of a long ancestral line of famous pocket watch movements from the Schaffhausen manufacturer and is ideally suited for large wristwatches with hand winding. The first Portuguese watches dating from the late 1930s were already equipped with pocket watch movements. Based on the 98000-calibre family that has been built and nurtured since the 1920s, it now combines tradition with the latest watchmaking advances. The finely decorated nickel-silver three-quarter bridge evokes the design principle of the earliest Jones calibres. Its visual counterpart is the bridge for the minute tourbillon provided with a gold medallion (Probus Scafusia). The balance frequency of this drive mechanism has been increased from 18,000 to 28,800 beats per hour. The index-free balance thus oscillates four times per second as it rotates in its cage. Precision adjustment is carried out via four adjusting screws. The higher frequency in conjunction with the modern escapement system assures excellent accuracy.
The Portuguese Tourbillon Hand-Wound, with a chunky crown used to supply a power reserve of 54 hours, is housed in a case with a diameter of 43.1 millimetres and a height of only 11 millimetres. Extraordinary things come in small numbers, however: this horological gem in 18 carat red gold is limited to 500 pieces.

IWC-manufactured pocket watch movement with hand winding and nickel-silver threequarter bridge, flying minute tourbillon with 47 parts; limited edition of 500 pieces
Calibre : 98900
Beats : 28,800/h /4 Hz
Jewels : 21
Power reserve : 54 h
Winding : hand-wound
Tourbillon weight : 0.689 g
Materials :   

watch in 18 ct red gold with a black dial and a black alligator leather strap, folding clasp in 18 ct red gold
Glass : sapphire, convex, antireflective coating on both sides
Back : see-through sapphire-glass back
Water-resistant : 3 bar
Diameter : 43.1mm
Height : 11mm