Blancpain Le Brassus & 13R0

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Le Brassus 8 Jours
and Caliber 13R0

by Ron DeCorte

November, 2006

Click the watch images to view larger versions

Sometimes things are not as they seem. This is especially true in the Vallee de Joux Switzerland, home of the Blancpain manufacture. So it was as I headed out from my small apartment in the Vallee that all seemed quiet on that mid-August morning, calm and serene with little hint of change in the air.

Five minutes later, arriving in Le Brassus, things were much the same as I remembered. The Blancpain manufacture, sitting a few hundred meters up from the village center, is deceiving in size and understated presence. The only thing I knew prior to opening the front door was that Blancpain had a new movement they wanted to show me. What I learned during the course of the day is that the wheels of development can turn without disturbing the tranquil environment of Vallee de Joux.

I’ll pause for a moment to set the stage in more detail so as to make the remaining parts of this article a bit more clear in terms of chronology. I first met the new Blancpain 13R0 movement in August of 2006 and made all movement photographs during that time at the Blancpain manufacture in Brassus. Upon my return to Switzerland in mid-October, I was able to photograph the finished watch, “Le Brassus, 8 Jours" in Geneve. As a matter of convenience, I will reverse the process in this article bringing you first the finished watch and then the movement details.

The “Le Brassus, 8 Jours” is the first watch to use the totally new 13R0 movement, of in-house manufacture, from Blancpain. It’s the new 13R0 movement that is the star of this article (by the way that’s a zero at the end of the movement designation). Using three barrels, the 13R0 achieves 8 days of power reserve and according to Blancpain will be the movement design they will use as a base for some Blancpain watches, with the possible exception of the tourbillons.

Available only in 0,950 platinum and limited to 260 pieces, the "Le Brassus, 8 Jours" shows off its Blancpain heritage with clean, simple, and classic design.

The dial is clear, free of extraneous clutter, and easy to read. At the 12 O’clock position the 8 day power reserve indication is raised slightly above the other markers. Applied hour markers are located on the second tier, and a date window at 6 O’clock completes the dial functions.

From the back and side, and I’m giving you several different photos here, the movement is really quite special.....

Click here to view an animation of the 13R0 in .wmv format (requires Windows Media Player)

Click here to view an animation of the 13R0 in .mov format (requires QuickTime)

The 13R0 movement is decorated in typical high grade finish with Geneve waves (Cote de Geneve). I suppose this terminology has its roots in the wave patterns on Lake Geneve (Lac Leman).

Several plates and/or bridges can be laid out on a single plate of metal and machined simultaneously. In this case, the center wheel bridge and escapement cock are machined from a single block and the Geneve waves are applied prior to the individual pieces being separated.

Many of the larger jewels are set in “chanton-like” settings. In earlier days gold chantons were used to set the jewels and the chantons then set into the plates and bridges. Times have changed. With today’s technology it’s far more accurate to make a very precise hole for the jewel directly into the plate or bridge and then make a sink, or recess, around the jewel that gives the impression of a chanton-set-jewel. This isn’t an easy process but makes a great impression, and more importantly establishes greater accuracy in wheel and pinion placement.

If you have a keen eye for detail, you might notice that the balance wheels photographed in this article are of two different colors: gold and grey. In both instances, the balances are made from titanium, but in one case the titanium is plated with gold and in the other case not. Since making these movement photographs in August, Blancpain has decided that the balance wheels will be natural titanium gray.

The titanium balance wheel uses 4 timing (regulating) screws to make fine timing adjustments. Given that titanium is incredibly light, it is the gold balance screws that are at the heart of timing regulation.

As for the timing screws, the head is of square shape rather than the usual slotted type. This shape facilitates easy manipulation for the final timing, and also reduces the possibility of damage via a typical screwdriver.

The balance spring is a Breguet type over-coil and uses no regulator, in other words free sprung.

With the Balance cock and barrel(s) bridge removed, we can have a better look at how the three barrels work. Barrel “A” is the first barrel in the chain and is directly connected to barrel “B” via their perimeter teeth. The mainsprings used in barrels “A” and “B” are 0,09mm thick, and importantly these mainsprings are not directly connected to the barrels but instead use a slipping bridle the same as an automatic watch. Also connected to barrel “B” is the power reserve mechanism “C”. Barrel “B” and barrel “D” are directly connected via their barrel arbors by intermediate wheel “E.” Barrel “D” differs from barrels “A” and “C” in that the mainspring is thicker, 0,10mm, and is also directly connected to the barrel at its outer end.

So here’s how it all works together to provide an 8 day power reserve for the 13R0: as the watch is wound (this is a manual winding watch), the mainsprings of barrels “A” and “C” are wound in tandem since they are directly connected via their outer teeth. As barrels “A” and “C” gather strength together this power is transferred to barrel “D” that feeds the power directly to the time train and the escapement. In a nutshell, barrels “A” and “C” are the power reserve that feed barrel “D” that is the stabilizer in the equation of power that is ultimately transferred to the escapement. It’s via the external coupling of barrels “A” and “C” that provides a consistent amount of power to barrel “D” that the 13R0 can maintain stable amplitude of power to the escapement over the period of 8 days.

Under the dial, the calendar mechanism is a bit unique. When manually setting the date forward at the end of certain months, wheel “A” engages with the date disc to move it forward. If trying to set the date in reverse the shape of wheel “A” disengages it from the date wheel and allows no action, or damage to the calendar mechanism.

On a day to day basis it is wheel “B” that makes one revolution per day, and via the spring attached moves the date ring one position, or one day in advance. Jumper arm “C” and its tension spring “D” see to it that the calendar disk is firmly positioned at each jump of the date.

For more information please visit the Blancpain web site: www.blancpain.ch

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