Transparent Tank: The Cartier Tank Cintrée Skeleton

The Cartier Tank has appeared in dozens – maybe hundreds, if you include the Must de Cartier models, and I do – of different versions and once you get outside the fundamental models, like the Tank Normale and Tank Louis Cartier, one of the most popular versions is the Tank Cintrée. The Cintrée (the word means “curved” and the elongated shape of the Cintrée is curved to fit the wrist) was one of the earliest Tank models, having been launched in 1921, and its case design was a radical departure for both Cartier and watchmaking in general. Today the Cintrée still looks every bit as elegant as it did in 1921 and it remains a mainstay of Cartier’s collections. The Cintrée Skeleton was produced for the (supposed) 100th anniversary of the Tank, and it’s a rare example of a Cintrée with a shaped, openworked movement – the Cintrée, contrary to the popular belief that a proper watch has a shaped caliber, used a round, 18 jewel movement designed by Edmond Jaeger, and signed EWC.

Cartier did not produce its first openworked Tank until surprisingly late in its history – one of the first, if not the first, was a 150th Anniversary limited edition of 15 pieces, with a round movement. This was a 1997 release and I’ve seen photos of it in exactly two places – one, in a post by Carson Chan on Instagram from October of last year, and the other, in the 1998 edition of Franco Cologni’s “Cartier: The Tank Watch,” which is out of print but worth looking around for if you want a proper history of the Tank that names names and gives dates. There was the Cartier Tank Noctambule, which was a unique piece with lume applied to the movement bridges; the 2013 Tank MC Skeleton, and the Tank LC Sapphire Skeleton in 2014. It’s a rare bird (well, skeletonized Tanks of any kind are) but there was also a Tank Obus with a skeletonized movement, released in the early 2000s, in the Cartier Paris Privée Collection.

This particular version of the Cintrée (WHTA0022) has a movement which was designed from the beginning as an openworked caliber, and it shows in the logic and clarity of the layout. There are a couple of different ways to make an openworked watch. The most traditional (and also the most time-consuming) is to take an existing movement, make holes in the mainplates and bridges with a piercing file, and then use an extremely fine saw to remove as much metal as possible; ideally you are left with an almost invisible framework for supporting the gear train and other mobile components. The movement, after the excess metal is removed, usually gets further embellishment in the form of anglage and polishing on the inner edges created by the saw, and occasionally the remaining movement plates and bridges also get engraving of their own. The results can be almost unbelievably fine and fanciful, but the one drawback is that you are more or less stuck with the architecture of the original movement. This is not necessarily a problem, though, as part of the appeal of a traditionally skeletonized movement lies in the drama of the transformation of the base caliber.

Openworking nowadays is generally done with wire erosion machines but the sense of drama is the same, although the tools are different. The other way to make an openworked watch is to design a movement from scratch which has an open design, which is what Cartier does pretty much across its entire line of openworked watches. The disadvantage with this approach is that whatever movement you develop is essentially a one-off for the model for which it was designed, although with some caveats – escapements, balances, gear trains and keyless works can all be adapted from other existing movements, even if the plates and bridges can’t. The advantage of course is that you can within reason do whatever you want with the basic movement architecture and in this case, it means Cartier was able to create a movement not only shaped to fit the case, but also with a layout that emphasizes the originality, proportions, and curvature of the 1921 design.

All of the gear train components are arranged along a single vertical axis, with the mainspring barrel at 12:00 and the center wheel, third, fourth, and escape wheels all in one line. The balance wheel is relatively thin and light but this allows the movement, caliber 9917 MC, to produce a very respectable 60 hour power reserve. The movement has no mainplate in the conventional sense of the word; instead, the minute track acts as an upper bridge, and the components are sandwiched between it, and the lower bridge, which is very slightly curved to fit the curvature of the case. The symmetry of the movement is impressive; the only notable asymmetry is thanks to the arrangement of the keyless works and hand-winding gear train, which require a cut-out in the lower bridge in order for the gears to reach the ratchet wheel on the mainspring barrel.

This is a comparatively large watch, relative to a conventional Tank, although that doesn’t imply an excessively large case; the Cintrée was in 1921, a larger watch by design and the curvature of the case means that even at 46.3mm x 23mm x 9.8mm, it’s a very comfortable watch to wear.

Watch movements with an inline architecture for the gear train are a rarity; two other notable examples are the Corum Golden Bridge, and the Jaeger-LeCoultre caliber 101. Both of these watches modify the position of the crown; in the Golden Bridge, the crown is at 12:00, which allows the space on either side of the linear movement bridge to remain completely open; in the JLC 101, which was introduced in 1929 and which is still the smallest mechanical watch movement ever made, the crown is located on the back of the movement. For the Cintrée however, I think either configuration would be out of character; there are things you can change about the basic design of the Cintrée without upsetting its visual identity but the position of the crown isn’t one of them (and hey, you gotta have a blue sapphire cabochon).

Watches with rectangular cases that have a pronounced curvature are a fascinating sub-category of collectibles; other notable examples include the Movado Polyplan, and the Gruen Curvex. They do not of course have the pragmatic air of instrumentality found in round watches, and certainly not in round sports watches (of which we have today, to put it charitably, an embarrassment of riches). They are instead an exercise – especially with a shaped, curved movement – in combining a kind of Roaring Twenties, Art Deco era sophistication – you might say, an elegant instrument for a more civilized age.

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