SAVOIR FAIRE How does a split-seconds chronograph work?

It was originally devised as a way to time simultaneous events. Here is how it works: Activating the pusher at two o’clock launches the two superimposed chronograph seconds hands simultaneously. When the first event ends – say, a runner reaches the finish line – the pusher at nine o’clock is activated to stop the top hand allowing you to record a first time. Meanwhile, the other hand continues revolving around the dial,  effectively splitting the seconds as the English name of the complication aludes to. When the second event ends, pressing the pusher at two o’clock stops the lower chronograph hand, allowing the wearer to read both times as well as the difference in between them. To resume, simply press the pusher at 9 o’clock once more and the upper chronograph hand will catch up with the lower one, thus illustrating the French name of the complication: rattrapante. The chronograph mechanism can then be reset by pressing on the pusher at 4 o’clock.

A single chronograph is complex enough, as it must tap into the running movement by way of cams and a column wheel. The split-second mechanism, however, is infinitely more complicated, as it requires an entire layer of ingeniously designed parts to decouple and stop the first chronograph seconds hand, and then return it instantly to the running mechanism, where it must take up its former position right under the second chronograph hand, which might be still running. As an expert in the manufacture of chronometers and chronographs, TAG Heuer has co-developed the movement of the TAG Heuer Monaco Split-Seconds Chronograph, Calibre TH81-00, with the esteemed Vaucher Manufacture Fleurier. The choice of the assertive square Monaco case was judicious, as the pushers fit comfortably on the broad side of the watch,with the rattrapante pusher at 9 o’clock evoking the original position of the crown from 1969.

Every detail was carefully thought out for this new timepiece, including the incorporation of the new Calibre TH81-00. It beats at 36,000 vph, ensuring 1/10th second precision. The entire movement, featuring 364 components, weighs a mere 30 grams. Finally, the caseback is crafted entirely in sapphire, revealing the inner workings of the movement. In short, this is a true modern reinterpretation of an icon.