Ideal for comparing the performances of two competitors
during a race, this watch can measure two time intervals
Based on the same principle as the regular chronograph, the split-second chronograph adds an extra subtlety: the capacity to record and display an intermediate time. This mechanism allows two time intervals to be compared, for example the times of two runners.
When stopped, the seconds hand hides another hand. When the chronograph is started, the two hands start moving in lockstep one above the other, until another press of the split-second pusher separates them. The first hand freezes while the other carries on turning. It is then possible to read the intermediate time while the other chronograph hand continues its progress. A second press makes the stopped hand catch up with the moving hand.
Constructing a mechanism which allows two hands to function alternately synchronously and independently while ensuring maximum precision represents a considerable technical challenge. The split-second chronograph, based on a mechanical clutch and memory system, is one of the most complex watch complications to produce.
Blancpain’s split-second chronographs are all fitted with a second column wheel, the mechanism used in the most refined and prestigious chronographs, to control the stopping and catching up of the chronograph seconds hands. An isolating wheel, a clamp serving as a brake, an isolator, as well as much painstaking fine adjustment work, round out the device to transform a chronograph into a split-second chronograph.
Blancpain presented a world first in 1989 with the calibre 1186, the first self-winding split-second chronograph. Before then, no split-second chronograph subject to the constraint of a traditional double column-wheel system had featured the additional complication of self-winding. The previous year, the Le Brassus Manufacture had already created the 1181 movement, the world’s thinnest hand-wound split-second chronograph (calibre 1181).
All Blancpain split-second chronographs are also fitted with the flyback function, providing an instant reset to zero and instant restarting of the chronograph. This function works by pushing the pusher at 4 o’clock.