IWC Ingenieur Constant-Force Tourbillon (IW5900)

SIHH 2013…

IWC Ingenieur Constant Force Tourbillon IW5900

IWC Ingenieur Constant Force Tourbillon IW590001 Watch

And the piece de resistance award in the IWC Ingenieur family this year goes to this spectacular Ingenieur Constant-Force Tourbillon.  The $290,000 piece features a 46mm integrated platinum and ceramic case.  The IWC caliber 94800 features a patented constant-force mechanism (which I recently discussed a bit here, if you want some background), integrated in a tourbillon.  The mechanism provides for extremely accurate ratekeeping over at least 48 hours, according to IWC.  It is a double barrel movement with 96 hour power reserve when fully wound; the configuration is surely needed to power the constant-force tourbillon.  There is also a moon phase module (upper right quadrant of dial), with finely detailed moons and showing the 3 of days until the next full moon.  In the lower right quadrant is the power reserve display.  This is no doubt a fine piece, though I do find the interplay of platinum and ceramic in the case to be a bit unusual looking.  High-res and more, below.

 IWC Ingenieur Constant-Force Tourbillon (IW5900)

Price: $290,000

46mm platinum and ceramic case, hand-wound IWC Caliber 94800 (96 hrs power reserve, perpetual moon phase display, double moon for No/So hemisphere, countdown display to next full moon, constant-force tourbillon) IWC Ingenieur Constant Force Tourbillon Watch

IWC Ingenieur Constant Force Tourbillon Dial

IWC Ingenieur Constant Force Tourbillon Moonphase display

Turning to the caseback…

IWC Ingenieur Constant Force Tourbillon IW5900 Backview

IWC Ingenieur Constant Force Tourbillon Caseback

IWC Constant-Force Tourbillon

IWC Constant Force Tourbillon

For the new Ingenieur Constant-Force Tourbillon, IWChas integrated a patented constant-force mechanism into a tourbillon. It 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 the balance spring from where it is transferred to the escape wheel. In the process, the balance spring is put under tension once a second and the seconds hand in the tourbillon advances in one-second jumps. This ensures an extremely regular and precise rate over a period of at least 48 hours. After approximately two days, the movement switches from constant-force mode to normal mode, as can be seen from the second hand, which now starts to advance at intervals of one-fifth of a second.