IWC Grande Complication
This watch has over 650 parts. That’s five times as many as a typical movement, twice as many as the average car engine, all crammed into a space small enough to wear comfortably on the wrist. But it’s not the number of parts that makes this watch a grand complication, it’s the way they’re put together. Let’s find out why.
As you’d reasonably expect, this watch displays your hours, minutes and seconds because—well, it’s a watch, isn’t it. This can be attributed to a good 150 parts of the calibre 79091 movement, which leaves us with about 500-odd to go. So, where have they all gone?
The first culprit in this parts-hog of a watch is what is often considered a fairly simple complication, the chronograph. Believe it or not, this particular movement actually starts life as an off-the-shelf ETA 7750 chronograph, stripped down, refinished and rebuilt with modified and completely new parts to bring it into line with IWC’s standards.
Fact of the matter is that it takes another 150 parts to add a chronograph to a time only ticker—and here’s why: a watch movement, fully wound, delivers a constant stream of information to the hands that we read as time, whereas the chronograph is an on-demand system that we start and stop at will.
This requires the meshing of a whole other set of hour, minute and second hands, as well as the levers to engage them, a brake to pause the motion when they’re disengaged again and hammers to reset them back to their starting positions when all’s said and done. And there are pivoting wheels with fine teeth designed to mesh without jamming, heart-shaped cams that return the chronograph hands perfectly back to zero every time, all without disturbing the obviously important accuracy of the movement.
But a chronograph is no grand complication on its own, oh no. It takes a lot more than that, and when it comes to this IWC, it’s just getting started.
It’s hard enough to remember the day of the week let alone the date, yet somehow the Grande Complication will tell you both of those, plus the month and the year as well. It even knows what phase the moon is in and whether or not it’s a leap year.
And that’s still not the most impressive part—unlike other perpetual calendars, which require the individual setting of each component to get it all going, this has it all figured out, so all you have to do is wind the crown on and let it do the rest. It knows, for example what the date is on the third Wednesday in July 2018, and just how much of the moon you’ll get to see. It even knows when one century ends and another begins.
The whole operation revolves around what IWC calls the program wheel, a gear with 48 teeth of different lengths that determine the number of days to be found in each month of each year over a four-year cycle, incorporating a leap year. It’s remarkable, really, because of its simplicity, and allows an unprecedented level of information to be so accurately displayed on the dial.
Built as a module that sits astride the base chronograph calibre, this perpetual calendar mechanism has IWC watchmaker Kurt Klaus to thank for its inception, designed in 1985 by the legendary man in a bid to combat the decline of mechanical watchmaking. This was in a time before computer aided design, and was the last complication to be penned by hand at IWC—if you can even imagine anyone doing that at all, ever.
We’ll leave the perpetual calendar on one final note, perhaps the most impressive part about it: all this ingenuity, invention, and most astoundingly, mental athletics, and the module requires less than 100 parts—which leaves us with 250 parts still to go.
Two hundred and fifty parts, and only one of them can be seen. The minute repeater isn’t the most visually striking complication, but the straight out fact that it takes a master watchmaker over 300 hours to assemble one is rather telling. This is the icing on the cake that takes the IW3770 from merely complicated to being a grand complication.
Its operation is simple. Pull the slide lever down on the side of the case, and the time will be relayed to your ears by a series of pitched chimes thusly: high notes for hours, dual chimes for quarters—15, 30 and 45 minutes—and low notes for the remaining minutes. It’s such an unassuming complication that it almost belies its own complexity.
Consider this: the watch has to know what the time is. Sounds obvious, but when you peel back the basic timekeeping mechanism, you see that the hands are simply mounted to cylindrical pinions turning at different speeds—the watch has no idea how the hands themselves are aligned on the pinions.
To overcome this, each hand has an associated cam, stepped for the maximum number of chimes it can offer. The last cam, the minute cam, is especially complex, taking into account the four quarters of the dial on to which it must add minutes.
When the slide lever is pulled—which operates on an all-or-nothing mechanism to prevent a failed action—levers with a rack of teeth, also corresponding to the maximum amount of chimes per indication, are drawn back against a spring. They ‘read’ the cams; that is to say the steps on the cams block the levers so only the required number of teeth on the rack are presented to the gong.
The slide lever is released and the tensioned spring drives the levers home one at a time, the rack of teeth triggering the hammers that strike the gongs, telling you the exact time to the minute. It’s a complication in the most accurate sense of the word, each component and each action fine-tuned during assembly to get it working properly. It’s no wonder it takes a master watchmaker 300 hours to put one together.
So, there you have it. There may be over 650 parts that go into this watch, but it’s the genius, the invention, the skill that goes into designing, making and assembling them in just the right way that makes this IWC a true grand complication.
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