Patek Philippe

Mark in Paris
[Purist]
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[Anniversary Year] 10 years: Patek's new Split-second Chronograph mvt - Inside the 5959P

It's been 10 years already since Patek Philippe has unveiled his first in-house Spilt-second chronograph movement: the CHR 27-525 PS.

As a reminder, here are the two versions produced:

It was the first chronograph movement designed and manufactured entirely in-house for the brand but it was also the slimmest of its kind (27.3 x 5.25 mm chronograph with split-second) in the watchmaking world. It is thinner than the Lemania based CH 27-70 but with an additional Split-second complication.

People who discover Patek's collection sometime ask, wisely, why such a difference in pricing between models which seem to look alike (i.e. same complication choice but much thinner).

Such a slim movement is really hard to design because it is made of smaller parts which are more difficult to manipulate in the manufacturing process of course but also because these specifications make the parts much more subject to reliability issues, may it be concerning the thin baseplate and bridges (important for the overall rigidity) or the resistance to shocks and wear and tear effects on the smaller parts (axles, pinions etc ...).

And, last but not least, the finish is of a very high level, especially when we consider the number of parts. Hence the beauty of the caliber is not only appealing due to the decoration but also because of the bridges and levers shapes.

The movement is equipped with an isolator that neutralizes the Rattrapante drag on the second sweep hand, thus allowing the torque output to remain quite constant.

And don't forget this movement is housed in the 33 mm case of the 5959P reference. Patek Philippe really walked the opposite direction from the increasing case size trend. This monopusher 5959P is incredibly elegant, very legible and keeps quite nice proportion regarding its width. Last but not least, the movement occupies the full volume of the case as you can imagine.

The choice of a lacquered dial was decided in order to keep the dial's thickness low compared to an enameled one for instance (thanks Suitbert for the explanation).

The least we can say is that Patek Philippe proved with this caliber (if it was necessary) that they perfectly master chronograph design as well as dimensions.

Happy 10 years birthday!

Cheers, Mark