For the first time in an IWC watch, the Portugieser Constant-Force Tourbillon Edition “150 Years” combines a constant-force tourbillon with a single moonphase display. Available in a limited edition of 15 pieces for each dial variants and cased in a generous but very elegant platinum case measuring 46 mm in diameter, one can choose between a blue lacquered dial ref. IW590203 or a white lacquered one ref. IW5902002. Featuring a dial that seems a little busy at first, the constant force tourbillon takes the center stage at 9 o'clock. In horological poetry, the moonphase indicator between 12 and 2 o'clock takes elegance and grandeur a step further and both watches are fitted with a black alligator strap by Santoni with folding clasp.
With a prominent gauge-type power reserve indicator between 4 and 5 o'clock, a moonphase aperture between 12 and 2 o'clock and a very prominent opening for its constant force tourbillon with running seconds hand at 9 o'clock, the new IWC Portugieser Constant Force Tourbillon '150 Years' Limited Edition is a very good looking. Featuring Arabic numerals and a railway minute track in black, the blued hands create a perfect symphony along with the blue disc on the moonphase indicator.
The Movement94805 Calibre
The new IWC Portugieser Constant Force Tourbillon '150 Years' Limited Edition is powered by the manual wound IWC in-house calibre 94805 with a power reserve of 96 hours —4 days. This slow beating 41-jewel movement beating at a frequency of 18,000 vph features a tourbillon with integrated constant force mechanism. For this movement, IWC integrated a patented constant force mechanism into a tourbillon, which ensures that the amplitude of the balance — and thus the watch’s accuracy— remain absolutely constant, initially by disconnecting the escapement from the direct flow of energy generated by the gear train. The energy is stored temporarily in a balance spring and dispensed to the escape wheel. In the process, the tension in the spring is increased once a second and the seconds hand in the tourbillon advances in one-second steps. This ensures an extremely regular and precise rate over a period of at least 48 hours. After approximately 2 days, the mechanism switches from constant-force mode to normal mode, as indicated by the one-fifth-of-a-second movements in the seconds hand.
On the Wrist & Pricing
On the wrist, the new IWC Portugieser Constant Force Tourbillon '150 Years' Limited Edition wears slightly larger than its actual case size and more like a 47 mm watch. While both watches are really nice, we think that the blue lacquered dial is even more beautiful. Unfortunately at the time of our review, the blue dial reference wasn't available for us to photograph it.
Without a doubt one of the most impressive watches from our friends from Schaffhausen and a great looking watch that deserves a lot of attention due to its incredible Constant Force Tourbillon. For the money, not sure if we'd rather go with a Richard Mille instead.
Sticker Price $249,000 USD. For more info on IWC click here.