When Cartier presented its Rotonde Grande Complication Skeleton watch, the new discourse seemed fairly surprising. After years of launching original, inventive and disruptive watches, Cartier was thus announcing its first Grande Complication watch in the classic sense of the term. Its head of movement creation, Carole Forestier-Kasapi, immediately admitted that Calibre 9406MC was “by far the most complex movement ever created by the Manufacture”. Really? After such an array of such ‘crazy’ models as the Double Mystery Tourbillon, the Astroregulator or the Astrocalendar, could a ‘simple’ watch equipped with a flying tourbillon, a perpetual calendar and a minute repeater truly represent a challenge? As astonishing as it still may seem, the Rotonde de Cartier Grande Complication Skeleton is indeed a Grande Complication in a league of its own.

Let’s start by specifying that this model is the first of its kind to stem directly from the Cartier brains and workshops. While the brand had previously presented tourbillon watches with perpetual calendars and chronographs, these were movements produced by the so-called ‘motorists’ (specialised movement makers) and were thus not entirely exclusive. 2015 thus marks the year when, for the very first time, Cartier Haute Horlogerie has presented a movement that is both exceptional and classic. But classic does not mean simple, quite the reverse!

Cartier Rotonde de Cartier Grande Complication Squelette

Viewed from the front, the Rotonde Grande Complication Skeleton watch shows its flying tourbillon, its perpetual calendar and its minute repeater. But Cartier has chosen to hide its micro-rotor. © Cartier

Contrary to other models of this type, the Rotonde Grande Complication Skeleton is an all-new development and therefore features an integrated movement. This means it does not consist of several stacked complication modules, but is instead an all-in-one-piece system. Fair enough, the flying tourbillon carriage is the one customarily used by the brand. Some elements of its minute repeater are also pre-existent. The perpetual calendar section is however brand-new, and the operation of these parts as an inseparable whole, as well as their arrangement, are also new. It is precisely the degree of interaction between such demanding complications as a minute repeater and a perpetual calendar that creates a challenge.

Cartier is not however the first brand to launch such a movement. So what is so special about it? First of all, it is self-winding and that is extremely rare in itself. Most Grande Complication models save space by sticking to manual winding. In this case, the automatic winding is all the more sophisticated in that it is governed by a micro-rotor. Housed inside the thickness of the movement, this platinum half-disc single-handedly provides the force required to drive the 578 components of Calibre 9406MC. It nonetheless features a rare shape, since it is cut through its centre and appears to be split into two entities: one is visible on the back and the other can be seen through the open dial. It is in fact a single whole that allows the gear trains to pass through its middle in order to achieve that all-important space-saving.

Cartier Rotonde de Cartier Grande Complication Squelette

Calibre 9406MC powering the Cartier Rotonde Grande Complication Skeleton watch; in this instance one of the prototypes. © David Chokron/Worldtempus

This option has been chosen to meet the second fundamental objective targeted by the Cartier technical development department right from the outset of the project: the Rotonde Grande Complication had to be wearable. Most Grande Complication models are bulky monsters with a huge diameter and a totally unreasonable thickness. Calibre 9406MC measures just 6.72 mm thick, meaning less than the average seen in the most elementary chronograph and the same as many three-hand self-winding movements. The entire watch is just 45 mm in diameter, a pretty standard size in Haute Horlogerie, and only 12.57 mm thick, a record in the field.

The Rotonde Grande Complication Skeleton has two other distinctive features. The first is clearly visible and implied in its name. Its components are skeleton-worked apart from its mainplate, which is too busy holding hundreds of parts to be able to indulge in any open spaces. With that many parts and complications, one cannot really speak of transparency. Secondly, Cartier has undertaken a particularly advanced research programme on the acoustic quality of its minute repeaters, from which this model is the first to benefit. It will doubtless not be the last.

Cartier Rotonde de Cartier Grande Complication Squelette

The Rotonde de Cartier Grande Complication Skeleton watch on the wrist: a 45 mm-diameter case in 950 platinum that is just 12.59 mm thick. © David Chokron/Worldtempus