It’s hard to find the words to describe this timepiece. Somehow words like “beautiful”, “innovative” seem too small and meaningless face to face with this timekeeper. Having no hands but only jumping discs, this peculiar watch deserves his own special place between horological creations.
The watch presented is the 4N, a creation of François Quentin (with some help from Audemars Piguet Renaud & Papi team). The technical marvel in this watch is the jumping minutes and hours system.
The 4N collection comes in white gold, rose gold, blasted titanium, titanium DLC black, sapphire Planet Orange, sapphire Planet Blue and sapphire Planet Green.
The metal cases are satin-brushed with polished edges and polished back. On top, there is a sapphire crystal on the entire face surface for a good view of the movement and on the back, there is another sapphire crystal that reveals the main plate.
The Sapphire Planet’s case is manufactured from a monobloc sapphire and sapphire back cover to expose every detail of the movement.
Not only the case is interesting but also the strap system available is innovative and unusual: an efficient and rapid swap system with a quick release.
The most interesting point in this watch is not the fact that this is the best and the biggest jumping system available right now but how it tells time. Jumping hours is a known complication and used by many watches in various systems but the jumping minutes is rare.
To reach the 5.5mm height of the numbers, the classic system with three discs is not usable so another system with 10 discs was developed: for the hour function were used 4 discs assembled in a cage, a single disc for tens of minutes and another cage, with five discs, for the minutes.
“If jumping time is a very common complication, the opposite can be said for jumping hours and minutes, which is a much rarer complication. The watchmaking pieces available on the market are extremely few for an obvious reason: there is very little torque available for the jump from one minute to the next (to be precise, sixty times less than for that of an hour). In fact, the jump release and disc indexing mechanisms are liable to disturb the isochronism of the movement. Several high-end watchmaking parts mitigate this problem by using two driving forces, one for the time cog and one for the display. However, this mechanical principle has its own flaws: in particular, it requires a lot of energy and diminishes the watch’s supply proportionately. It also poses obstruction and synchronisation problems. The 4N-MVT01 only uses one source of energy, in this case, a double barrel.” – 4N Website
“The task was thus to conceive a very energy-efficient mechanical solution for the jump release and indexing of the discs, to work not just for 3 discs, but for 10.
The mechanical solution for the 4N-MVT01/D01 for the indexing of the discs is simple and innovative at the same time: each disc is linked with a wheel, which is itself geared in a fixed crown wheel. At the time of the jump, the cage turns, which leads to all the discs turning with each other, thanks to their wheel which is geared on the fixed crown wheel. This indexing is extremely energy-efficient, compared with traditional star-like, jumping or Maltese cross mechanisms.” – 4N Website
“The development of the jump release solution required a lot of time and iteration. The team of Renaud and Papi worked for many months to develop a system that Giulo Papi calls a mechanical transistor, i.e. a mechanism which, with very little energy, is able to actuate another mechanism which has much more energy. This jump release system makes a success of the feat of using neither a cam (Limaçon in french) nor a spring. Moreover the jump, i.e. the rotation of the cage on a time sector (1/5 of a turn for the minutes cage) is operated by arming a spiral spring over the course of a minute, at the end of which the jump release mechanism releases the rotation of the cage which is pulled by the spiral spring through a fifth of a turn.” – 4N Website
“This cinematic collection of the cage, discs and disc indexing is independent of the degree of winding of the cylinder; the same amount of energy is always used (the compression of the spring by the cage), thus allowing an optimum adjustment of the jump, however, wound it is (like a constant force). Thanks to these innovations the MVT01/D01 boasts an exceptional 237-hour fully-wound life span, which is almost 10 days, putting it way out in front of all other high-end watches with complicated displays, and all this with a spectacular animation every single minute.” – 4N Website
The 4N movement MVT01/D01 is made using 514 components and 78 jewels. These numbers are impressive and make the 4N watch one of the most complex timepieces on the market and the most complex jumping time ever.
Since two months are needed to complete one watch, only 16 pieces are available in different metal versions: gold, titanium and platinum.
The finishes used are extraordinary: double application of intersecting Côtes de Genève on the discs’ cage top which gives the illusion of dry carbon, beveling and polishing, satin brushed bridges, Côtes de Genève on the main plate with inner beveling, snailing on the gears. All the surfaces are Haute du Gamme finished.
The 4N-MVT/D001 is an example of horologic engineering: not only the fantastic finishes but the entire idea, design and final product. This manual wound movement has a power reserve of 237 hours – almost 10 days, reached with the help of two barrels with simultaneous transmission stop-work, a screw balance with 9.12mm diameter, a Breguet spring beating with 21600vph (3Hz) and a constant force system for the jumping mechanism with disc indexing done by gears. For an easier setup, there is a quick correction push-button for hours.
The metal versions are limited to 16 pieces regardless of the finish of the case: gold, titanium or platinum and cost 180000 Euro. The Planet Sapphire version is limited to 1 piece each colour: Orange, Blue, Green and cost 290000 Euro (with crown and hours push button in white gold).
Last year, in March 2016, at Baselworld was introduced the 4N SPINEL CERAMIC: the case middle of the piece is made ITR2 (a ceramic lightweight composite material) and synthetic spinel (polycrystal) to protect and to reveal the mechanism of the watch. The spinel crystal is impact resistant and lightweight, it has an almost equivalent hardness to sapphire and has very good transparency in the visible, ultraviolet and infrared light.
I would like to thank François Quentin and the team behind the 4N for the information, images and videos. Please visit the 4N Website for more information and for the list of Retailers.