The chronograph is an interesting category of complications, in that there are so many variations of the stopwatch function, each with their respective unique features. Here at Wound For Life, one of our favorite types of chronograph is the rattrapante, or as its more commonly known, the “split-seconds” chronograph. While oft confused with the similarly functioning “flyback” chronograph, the two are quite different, and when analysed, the rattrapante is arguably the more desirable variant.
Rattrapante is a french word, coming from the verb “rattraper”, meaning to catch up. When inspecting a watch with this type of movement, you’ll notice that on the center stack of hands, there is an extra chronograph seconds hand. Its purpose is to allow the user to track multiple times in succession without having to reset the chronograph. Once you’ve started the chronograph using the pusher at two o’clock, the two hands will track elapsed seconds simultaneously, until you’ve engaged the second stage of the chronograph. Usually, this is done using a pusher found at either ten o’clock, or integrated into the watch’s crown. Doing so will stop one of the hands, while the second will remain to track the time passed.
Where the flyback allows one to quickly stop and restart the chronograph using the single push of a button, the rattrapante lets one look back at the first timing, without having to remember it. With the exception of very few instances (potentially in military aviation scenarios), the rattrapante’s additional functionality will be found more useful than a flyback. Additionally, the effort to produce a rattrapante is greater, as it requires far more intricate clutch work — this is also the primary reason rattrapantes are typically so expensive.
Patek Philippe ref 5204
Not only does the mechanism require the use of two seconds hands, but the clutch has to has some sort of memory system to maintain position for the first ‘stop’. While both the main chronograph hand and wheel are running lock-step with the split-second hand and wheel, an isolator — activated with the correct split-seconds pusher — will stop the action of the split-second hand and wheel, allowing the main chronograph to continue. Once the main chronograph is stopped, the entire mechanism can be reset as usual. This action greatly increases potential inaccuracies, allowing almost no room for error (an excellent breakdown of Patek Philippe’s split-seconds chronograph).
One of the modern pioneers of the rattrapante, who is largely responsible for the mass awareness and revival of this complication, is Richard Habring, an Austrian independent watchmaker. With his strong philosophy of building relatively affordable watches that still bear mechanical sophistication, Habring, while working at IWC, designed a double-chronograph module that could be easily integrated into an ETA 7750. As most will know, IWC now offers what they call their “Doppelchronograph” movement on several models in the Aquatimer, Ingenieur, and most notably, their Pilot’s collection. What was most revolutionary about this innovation is that it was based upon a movement using a cam system, rather than a column wheel. Today, Habring2 sells the Doppel 3, a much less expensive offering than most IWCs, using a largely similar movement. In fact, since IWC’s patent on the doppel has expired, Habring has only refined it.
Habring2 Doppel 3
From Habring’s development, the rattrapante became considerably more reliable, due to its ETA base. Not only has this considerably driven down the price of watches featuring such a complication, but also has ultimately helped build awareness of a complication that was seen more often on ultra high-end, grand complications from the likes of Patek Philippe. The increasing affordability of complicated mechanical watches is a new trend that we here at Wound For Life are fully on board with, and hope to see continue.
by 
