A lever, two column wheels, two second hands and three push-pieces. That’s what a split-seconds chronograph boils down to. This extremely prestigious watchmaking complication is defined by its ability to time two events that start simultaneously but end at different times. When the first event ends, one of the watch’s two chronograph hands is paused. The second chronograph hand continues to run for the duration of the second event. At any time, with a push on the watch’s third pusher, the first hand can be made to catch up with the second (rattraper, in French), which is where the complication gets the name rattrapante. The two superimposed hands then continue their journey around the dial. If you were to look at the reverse of one these watches, its movement would immediately give the game away. You just have to count the two column wheels, or identify the large pincer-shaped split-seconds lever. This component is what stops one of the two seconds hands, and then lets it go again.
Nevertheless, despite its prestige and classic status, the split-seconds chronograph suffers from one major limitation. It can only measure intervals of less than one minute, because as soon as the interval exceeds 60 seconds, the catch-up or rattrapante function loses its point. So, in practice, it is only useful for timing events with a very short time interval. There are three alternative approaches which help to make up for this deficiency. But only three.
The first is a split seconds chronograph in the strictest sense – a Double Split, in fact. That is the name chosen by A. Lange & Söhne for its model that measures dual times over 30 minutes. It is the only watch capable of this feat, and it achieves it thanks to dual chronograph minute hands, located on a subdial at 4 o’clock. The Double Split has obviously proven its worth, since it has been in continuous production since 2004, without any changes, making it the oldest watch in Lange’s current collection.
To investigate the other solutions, we shall have to deviate somewhat from split seconds strictly speaking. In order to measure two times, two performances or two events at the same time, Louis Vuitton uses a watch with four movements and two column wheels. The Twin Chrono is also equipped with three subdials. It is a double chronograph with differential display, capable of timing two separate events, as well as displaying the difference between the two times, with a display on three individual subdials graduated into 60 minutes.
The final available alternative is the Royal Oak Concept Laptimer by Audemars Piguet. This chronograph records lap times for several consecutive laps by continuing to display the time of the previous lap. The Laptimer works like two separate chronographs combined into a single watch. When the first lap is complete, one of the two central seconds hands is paused, displaying the time for the first lap. As the second lap continues, the second chronograph hand continues to sweep around the dial. Once the second lap is complete, the second chronograph hand is paused, displaying a second time. Simultaneously, the hand for the first lap is reset to zero, and begins timing the third lap. And so the sequence continues. Each hand takes over from the other, after resetting to zero.
The split-seconds function remains highly sought-after, and difficult to produce. It features in top-of-the-range watches by Richard Mille, Vacheron Constantin and Patek Philippe, who see it as the pinnacle of the watchmaker’s art, and treat it as such. But given the complication’s limitations, the recent influx of creative solutions has begun to chip away at their monopoly on dual chronographs. And the watch world is all the richer for this ingenious input.
