One of the most unusual and interesting pieces of horological exotica I can remember ever seeing had a somewhat rocky start in life: the watch (or watches, as there are now several incarnations) made by Zenith and known as the Christophe Colomb.  Zenith was going through a period of experimentation, under its former CEO Thierry Nataf, and the watch now known as the Christophe Colomb was introduced –extremely confusingly –as the Defy Extreme Zero G Tourbillon, despite the fact that it wasn’t a tourbillon at all.  That was back in 2008, and since then, Zenith has, to the joy of many of its old fans and the interest of many new ones, taken a step back from the design excesses so characteristic of much of watchmaking in the first decade of the 21st century and given us a version of this horological invention that’s much more coherent from a design standpoint, as well as improved in certain aspects of its engineering.

Despite the fact that the Christophe Colomb sits squarely at the top of Zenith’s production in terms of complexity as well as exclusivity –or maybe because it’s so exclusive –it’s very rarely that one sees it in the metal, as enthusiasts like to say of a Close Horological Encounter of the Third Kind.  We recently had a chance to photograph one of these rare birds at Cellini, in New York’s Waldorf Astoria Hotel.  Because the watch is so unusual and exotic it is not well known even to many of the Zenith faithful –but it’s very much worth getting to know.

The Christophe Colomb was devised to address the same problem as the tourbillon (this was the rationale for the complication’s being called a tourbillon at first.)  One of the greatest challenges to accuracy in any watch is that watches tend to run at different rates when they’re in different positions with respect to gravity.  Adjusting a watch meticulously to keep, as much as possible, the same rate no matter its position is one of the most essential and most difficult crafts in watchmaking.  The tourbillon, Breguet’s ingenious brainchild, was patented in 1801 and attempts to cope with the problem by producing a single average error in all vertical positions; the watchmaker then need only adjust the flat positions to match the vertical ones and in theory, at least, one should have a perfect timekeeper (at least as far as the problem of positional error is concerned.)

Ever since Breguet made his first tourbillon, horologists have debated whether it actually adds anything in terms of accuracy, and even today opinion is divided.  There are, undoubtedly, extremely accurate tourbillon watches but as the co-maker of some of the most interesting in the world –Stephen Forsey, of Greubel Forsey –once pointed out to us, any improvements are at the cost of considerable increase in complexity and it’s always a struggle to gain more than you lose.

The Christophe Colomb takes its cue, in terms of solving the problem of rate variation across different positions, from ship’s chronometers.  Marine chronometers must keep extremely accurate time and to aid them in doing so, they were usually kept in boxes fitted with gimbals so that no matter how much the ship rolled, the chronometer was always (more or less) flat.  You can’t strap a boxed chronometer to your wrist, of course (though we’re sure at some point, somebody tried) but Zenith’s engineers adapted the idea to the wristwatch and the result is the Christophe Colomb.

The basic idea is to place, not the entire watch, but rather, the escapement and balance, on a gimbal-mounted platform.  This platform is visible in the Christophe Colomb as it floats inside a spherical enclosure built into the sapphire crystal, and can be observed both front and back.  (In case you’re wondering, the watch is actually very comfortable to wear –Zenith CEO Jean-Frédéric Dufour was kind enough to let us wear a prototype last year for an hour or so, and the slight protrusion on the back of the watch became essentially unnoticeable after a few minutes.)

The platform is weighted with gold on the bottom, to help keep it horizontal.

The mounting system consists of an outer gimbal ring, which rotates around an axis slightly angled with respect to horizontal (with the watch sitting with 12:00 uppermost) and the inner platform itself, which rotates on an axis at right angles to that of the outer gimbal; in this way the balance is always flat.

This two-axis system doesn’t compensate for any errors due to rotation around the axis of the balance, but as the balance is a fast beat El Primero type, vibrating at 36,000 vph, it’s not particularly vulnerable to deviation in rate due to rotational movement, which in any case is apt to be minimal with the watch on the wrist under normal conditions.  Zenith also calls the suspension system “gyroscopic” however, there’s no gyroscope –although the suspension system is often used for mounting gyroscopes (in inertial navigation and guidance systems, for instance, where the angular momentum of the gyroscope in its gimbals maintains a constant reference orientation.)  Fans of the movie Apollo 13 may recall a reference to the danger of “gimbal lock” during violent oscillations of the Command Module; this occurs when the deflection of the spacecraft threatens to exceed the ability of the gimbals to maintain a reference orientation.

Now, the idea is simple enough but making it work is far from simple.  For the escapement to get power from the mainspring, a gear system has to be set up that can transmit torque across both axes of the gimbal system.  This is done by arranging a driving gear on each axis, and then connecting them with two differential gear systems.

Most of us, if we’ve heard the term “differential,” are familiar with it from automotive engineering.  In a car, the differential splits the torque from the engine into two power flows –one to each driving wheel.  Since the two wheels will turn at different speeds –in cornering, for instance –the differential allows power to go from one source to two destinations that turn at different rates, without interrupting power flow.

A similar problem is solved by the differentials on the Christophe Colomb, to solve a related problem: getting power across each axis of rotation of the gimbal system, while mechanically subtracting the varying rotation of each of the two gimbals.

The first differential also transmits power across a 90 degree displacement (from the outer gimbal to the rotational axis of the inner platform.)

The second differential is more compact, and lies on the axis of rotation of the inner platform.

The gear train also has to change its plane of orientation 90 degrees where the going train on the mainplate transmits power to the first differential, and again, where the second differential transmits power to the escape wheel.  You can see the last driving wheel in the train on the inner platform, on the same plane as the balance; this wheel drives the (largely hidden) escape wheel, which appears to be made of silicon.

The second major element taken from classic ship’s chronometers is the inclusion of a chain-and-fusée for maintaining even torque across the entire power reserve of the watch (a minimum of 50 hours; the watch is manually wound.)

All this ingenuity, however, would be of intellectual interest only if the design weren’t so engaging.  We find the designs of the current generation of Christoph Colombe watches just irresistible –the spherical housing for the gimbaled escapement system, combined with the classic, even slightly antiquarian design elements in the dial and case, and the beautiful and very well done traditional movement finishing, all combine to make this one of the most tasteful high complications in the world.

Special thanks to Leon Adams, President of Cellini, and the very accomodating Cellini staff, for permission to photograph the Zenith Christophe Colomb Hurricane.  Currently available at Cellini New York; approximate price $280,000 in rose gold. Case, 45mm in diameter; thickness, 14.35mm and at the enclosure for the escapement and balance, 21.40mm.  Limited edition, 25 pieces world wide.  

Jack Forster is the Editor in Chief of Revolution Magazine (USA.) He also contributes to Revolution’s international and digital editions, as well as The Rake.  All photos copyright Jack Forster for Revolution Online.

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