Girard-Perregaux Constant Escapement L.M. Hands-On

Girard-Perregaux Constant Escapement L.M. Hands-On

by Tom Mulraney

If you were to ask a watch connoisseur to list out some of the most significant events to occur in the luxury watch industry over the last 12 months, chances are they’d include the unveiling of Girard-Perregaux’s truly incredible Constant Escapement L.M. And they would be absolutely right to do so.

Winner of the 2013 “Aiguille D’Or” – the top prize given at the prestigious Grand Prix d’Horlogerie de Genève – the Constant Escapement L.M. is a modern marvel of mechanical watchmaking, achieving what many believe to be the holy grail of mechanical watchmaking; constant force.

Girard-Perregaux Constant Escapement L.M.

Girard-Perregaux Constant Escapement L.M.

Girard-Perregaux Constant Escapement L.M. – Constant Force

Before I go into too much detail about the watch itself though I just want to spend a little time talking about what constant force actually means in watchmaking and why this development is so significant. Some of you will already be well-versed in this area and so I encourage you to skip further down to read the review of the watch itself but for those of you who don’t have a clue what I am referring to, please read on, it really is quite fascinating.

The premise of constant force is quite straightforward; essentially the idea is that output remains constant regardless of the level of input. For example, your car doesn’t suddenly start running slower because you have less fuel in the tank. It’s probably not something you even think about on a regular basis as the concept is so intuitive it is almost just taken as a given. Except in mechanical watchmaking.

Girard-Perregaux Constant Escapement

Girard-Perregaux Constant Escapement

Now, I should clarify here that in watchmaking the term constant force refers specifically to the escapement, that clever little mechanism responsible for transferring the power stored in the mainspring to the balance wheel (the latter of which is responsible for timing). To create the power in the first place the spring either needs to be wound manually by hand or, if it’s an automatic movement, through the miracle of kinetic energy (i.e. the energy you create when you move your wrist) This energy is then stored in the mainspring (also known as the barrel) and then slowly released over a period of time as the spring slowly (this period of time is commonly referred to as a movement’s ‘power reserve.)

So far so good, except there’s just one problem, how do you make sure the rate of energy delivered as the spring unwinds remains constant? The simple answer is that you can’t, at least not when using a traditional lever escapement as most mechanical watches do. Like anything that is tightly wound, the mainspring is bursting to unwind as soon as it given the chance, thus delivering a strong wave of energy at the beginning of the cycle. Inevitably though the rate of energy delivered to the balance wheel will at some point begin to slow. Now, admittedly the effect of this is almost imperceptible, with a degree of ‘balancing-out’ naturally occurring, and so most people are willing to tolerate a +/- 5 second difference.

Girard-Perregaux Constant Escapement L.M. Calibre

Girard-Perregaux Constant Escapement L.M. Calibre

That doesn’t mean this traditional method is satisfactory however. You have to remember that at their core watchmakers are inventors and creators (why else do you think they wear the white lab coats?) and so they love nothing more than to come up with innovative solutions to age-old problems. And they don’t come much more age-old than this. In fact, according to Girard-Perregaux the issue of constant force has plagued watchmakers since the dawn of time. I’m not sure if it goes back quite that far but there is definitely history there of famous watchmakers trying to solve this very issue. So, what have Girard-Perregaux done that is so different?

Well, unlike previous solutions, which found ways to better regulate the flow of energy from the mainspring (i.e. making it slightly more linear), the team at GP developed a way to make it absolutely linear. That means there is no drop in amplitude over time, regardless of the remaining energy in the barrel. To do this, they re-envisioned how an escapement should look and work, which included placing a remarkably thin (6x thinner than a human hair), vibrating silicon blade right through its central axis. The science behind it is probably a bit technical for a watch review but essentially this blade is able to store energy up to a certain threshold before snapping back in the opposing direction, pushing the balance wheel forward, counteracting the variable energy of the barrel and releasing the same amount of energy simultaneously.

Rather than confusing you (and myself) further though, it’s probably easier just to show you this cool video from Girard-Perregaux:

Girard-Perregaux Constant Escapement L.M. – On The Wrist

Now that we’ve covered the technical elements in some detail, it’s time to focus on the aesthetics. The first thing you need to know is that the Constant Escapement L.M. is a big timepiece, 48mm big. Presented in a gorgeous white gold case it sits comfortably enough on the wrist, although you’ll definitely never forget your wearing it. Surprisingly, the 3hz manually wound caliber is no thicker than 8 mm, while the case itself measures 14.63 mm.

Girard-Perregaux Constant Escapement L.M. - Wristshot

Girard-Perregaux Constant Escapement L.M. – Wristshot

The dial is extremely clean, with the focus undeniably on the butterfly-wing escapement, which takes up the entire lower half of the case. And rightly so, there is an incredible amount of detail to take in and the open design allows you to really get up close from all angles. Hours and minutes are shown on an off-center sub-dial at 12 o’clock, with small seconds indicated by a large central hand.

Turn the watch over and a wide open sapphire glass back held in place by 6 screws offers yet more breathtaking views of the remarkable, three-dimensional movement. Again, there is a lot to take in, so take your time and really look around. Finishing the look is a supple hand-sewn alligator strap paired with white gold folding clasp.

Girard-Perregaux Constant Escapement L.M. - Caseback

Girard-Perregaux Constant Escapement L.M. – Caseback

Undoubtedly the Girard-Perregaux Constant Escapement L.M. won’t suit all tastes but bear in mind that this is not a watch that has been designed for every day wear. Rather this is a showpiece, a celebration of an incredible achievement, designed to put the constant-force mechanism on show more than anything else. What is really exciting, is the possibilities of what’s still yet to come. Inevitably this new escapement is destined to become part of Girard-Perregaux’s mainstream production and that is when the real fun will begin. The Girard-Perregaux Constant Escapement L.M. retail for price of $123,500.

    Author Bio

    Articles by Tom Mulraney


    Tom Mulraney is the CEO and Editor of The Watch Lounge, an online magazine dedicated to luxury watch lovers that he founded in 2009. Although passionate about all things horological, he is particularly fascinated by independent watchmakers, often travelling the globe for a chance to spend some “hands-on” time with their breathtaking creations.