Complicated: 33

For almost four years, the Cartier Fine Watchmaking

Collection has been the focus of an unprecedented

burst of creativity, culminating at this year’s SIHH

with the official launch of the incredible Rotonde de

Cartier Astrorégulateur, housing the Calibre 9800

MC, to wide and immediate acclaim. James Gurney

Overcoming Gravity The Rotonde de Cartier Astrorégulateur

The Astrorégulateur and Calibre 9800 MC testifify to Cartier's deep-felt commitment to fine watchmaking. The movement compensates for the effects of gravity on the timing mechanism in vertical positions and is the subject of four patent applications.

34: Complicated

Despite an all-day session at the Fondation Cartier pour l’Art Contemporain in Paris, as well as an hour at the Geneva SIHH this year, Cartier’s fine watchmaking offering remains a bewildering phenomenon to get to grips with. It may be three years since the brand made public its intention to take a lead at the sharpest edge of movement development, but there is still a residual surprise that Cartier is active in this sector at all – this being a pursuit normally the preserve of independent ateliers driven by youth and impetuosity.

Cartier’s output has also been frenetic, with numerous ‘plain’ tourbillon movements, skeletonised movements and a mini-series of extraordinary creations such as the Astrotourbillon and the ID One Concept watch. And not forgetting that this all takes place alongside the production of

fine-jewellery watches and designs such as the Ballon Bleu, which sells in sufficient numbers to make it a'Top 10' brand in its own right. That Cartier has a structure that can cope equally with volume and unique pieces is a tribute to its management.

Such pre-amble is a way of avoiding for a moment quite how complicated the Rotonde de Cartier Astrorégulateur really is. In the search for ever-more reliable movements, there are numerous avenues to explore, from examining the fine interaction of pallets and teeth in the escapement to experimenting with new balance-spring materials. While good work is being done in these areas, see Cartier’s own ID One or Patek Philippe’s new GyromaxSi balance, watchmakers are constantly drawn back to the tourbillon and what they can do to improve it.

Cartier’s 9451 MC Calibre de Cartier Astrotourbillon is a manual-wind movement installed in a 47mm titanium case. The watch has a sporty look and feel unlike other tourbillion complication watches on the market with the carriage positioned above the movement.

Overcoming Gravity: The Rotonde de Cartier Astrorégulateur

The old and the newWhile its central idea – that of compensating for the constantly changing gravitational environment a watch exists in – is beguiling, there is little evidence that tourbillons really make a difference in themselves. Nevertheless, they are much in demand and perform well thanks to the care required to produce them. That tourbillons are so visually appealing, means watchmakers constantly return to the idea, looking to find new ways to improve on it, from multi-axis as perfected by Greubel Forsey, to various orbiting tourbillons, such as Ulysse Nardin’s Freak, Breguet’s Messidor or Cartier’s own Astrotourbillon. All these work by adding a second (or third) layer of compensation – one axis, good, two better, being the main idea.

Carole Forestier’s approach (she is Cartier Haute Horlogerie’s Head of Department) is fabulously different. Instead of compensating for positional errors over time, the concept for the Astrorégulateur is to remove the possibility of positional error. By integrating the escapement with the winding mass, the balance is always

in the same position. (This, by the way, is the easy part.) As you move the watch, you can see the escapement and balance are fixed to the rotor and, disconcertingly, the seconds also move with mass or more precisely in relation to the mass and the time shown – this is a watch, that, in a horological first, can actually make you feel seasick!

The slightly disturbing action of the watch is reflected, unsurprisingly, in the mechanics that make this simple idea work in practice. The main problem being, how do you supply power from the mainspring to a target that is moving at varying rates of acceleration and braking? The answer is in the two different sets that are incorporated into the 9800 MC calibre. These ensure that the torque delivered remains constant – without a differential, the escapement would constantly be freeing or braking the torque from the mainspring. The differential sets equalise shifting torque ratios in a similar way to what happens with the rear axle of a car when it corners, allowing both the escapement to run correctly and the seconds hand to retain its correct place.

The Pasha de Cartier skeleton flying tourbillon watch, is powered by the Calibre 9457 MC, a movement with a specially developed flying tourbillon escapement. Its bridges represent Arabic numerals – one of the distinctive features of the Pasha de Cartier watch.

Overcoming Gravity: The Rotonde de Cartier Astrorégulateur

36: Complicated

The proof is in the productAs a theory, this is just about simple enough to grasp – a quick glance at Wikipedia makes it all seem perfectly reasonable. However, the real attraction for Forestier and her team was, I suspect, the vast difficulty in getting the system to actually work. You can almost imagine the horological fun to be had in arguing over the lubrication needs of hypoid gear profiles as opposed to zero-handed spiral bevels. It should also be said that such differential sets underpin both the multi-axis tourbillons pioneered by Greubel Forsey and Zenith’s functionally similar Christoph Columb and that there might just be a little professional 'keeping up with the Joneses' at play. Where being Cartier rather than an independent atelier really helps with the Astrorégulateur is not just in the resources Forestier can command to crunch through mechanical problems, but also in the vast reserves of design expertise and the global reach of the company.

Don’t be surprised to see all 50 of the planned Astrorégulateur production sell out, despite competition from the Astrotourbillon, the Skeleton Flying Tourbillon and the most unfairly over-shadowed Calibre de Cartier Time-Zone, which does a much-appreciated job very elegantly – it shows home and travel times (selected with a city disc visible on the case side) and, rather pleasingly, shows the time differential.

Further information: www.cartier.co.uk

The Calibre de Cartier Multiple Time Zone watch uses the self-winding Calibre 9909 MC, with functions including the home time with day/night indication, the local time, adjustment for summer or daylight savings time and the time difference between the two selected time zones.