Q: Why are split-second chronographs so rare?
The split-second chronograph, which displays two measured times using two hands, is actually a mechanism with extremely high technical hurdles, as it can easily stop if the axis of the hands is not properly shaped.
2024/11/9 update
A: It's a mechanism that is prone to malfunction and has very high hurdles.
A split-seconds chronograph uses two hands to display two measured times. It's called a rattrapante in French. While there are many manufacturers of mechanical chronographs, there aren't many that can make split-seconds chronographs. Why are there so few of them, and why are they so expensive, when all it takes is one more chronograph hand?
Almost all split-seconds chronographs use a divided force to move the chronograph hands. Because the force required to move the hands is extremely small, they can easily stop if the hand shafts are not properly shaped. Furthermore, because the hand shafts are very long, even if the shafts are properly made, the resistance increases, increasing the likelihood of the watch stopping. Even for manufacturers capable of making chronographs, split-seconds chronographs are a nuisance due to their tendency to malfunction.
This masterpiece features split hands not only for the central seconds counter (chronograph second hand), but also for the 30-minute counter and 12-hour counter. All counters except the 12-hour split hand are equipped with isolators to prevent the hands from falling off when splitting. Manual winding (Cal. L132.1). 46 jewels. 21,600 vph. Power reserve of approximately 55 hours. 18K white gold case (diameter 43.2mm, thickness 15.6mm). Water resistant to 3 bar. Price upon enquiry. (Inquiries) A. Lange & Söhne Tel. 0120-23-1845
A. Lange & Söhne's "Triple Split" challenged this conventional wisdom. It features not only a chronograph, but also two 30-minute and two 12-hour counters, allowing for accurate display of three accumulated times in hours. It was based on the classic "Datograph." The addition of three split mechanisms to an already thick movement made it extremely thick. Because of the long axis, keeping this movement running properly was a real challenge. However, A. Lange & Söhne succeeded in keeping this monster running by firmly fixing the axis and ensuring it never wobble.
Breitling Moves the Splitter Mechanism to the Dial Side
Breitling's Cal. B03 movement is a model that has achieved a split chronograph function by adding the split mechanism to the dial side, rather than the case back where the chronograph mechanism is located. The photo shows a discontinued model. Automatic winding (Cal. B03). 28,800 vph. Power reserve of approximately 70 hours. 18KRG case (45mm diameter). Water resistant to 30m. (Inquiries) Breitling Japan Tel. 0120-105-707
Another challenge was Breitling's chronograph movement, Cal. B03. Because this movement has an automatic winding mechanism, it would be extremely difficult to add a split-seconds mechanism to the case back. However, by placing the split-seconds mechanism on the dial side, Breitling not only easily achieved the split-seconds mechanism, but also succeeded in shortening the axis. This is probably one of the most complete mass-produced split-seconds chronograph movements.
