Tricompax

The term was born at Universal Genève, which in the 1940s christened Tri-Compax a watch with three distinct functions: chronograph, complete calendar, and moon phases. Today the meaning has narrowed, and quite casually: almost everywhere «tricompax» simply indicates the arrangement of three chronograph subdials on the dial. Those who use the term in its original sense and those who use it in the current sense don't always understand each other, and it's worth knowing before opening your mouth in a negotiation.

In the modern and widespread version, the tricompax is a three-register chronograph: small seconds, 30-minute totalizer, 12-hour totalizer. The three subdials occupy the symmetrical positions at 3, 6, and 9 o'clock, with variations depending on the caliber. The most common configuration in Valjoux calibers of the 1950s and 1960s placed the small seconds at 9 o'clock, the minutes totalizer at 3 o'clock, and the hours totalizer at 6 o'clock. Some texts cite different arrangements — minutes at 12 o'clock, seconds at 9 o'clock — and this depends on the specific caliber, not on a single rule. I've disassembled enough Valjoux 72 and Valjoux 23 movements on my bench to know that no canonical position exists for all of them.

The difference from the bicompax is structural: the bicompax has only two registers, usually chronograph minutes and chronograph hours, and the small seconds either are missing or incorporated into the center hand. The rattrapante is another category entirely: it doesn't add a subdial, but doubles the seconds hand to measure intermediate times without stopping the main chronograph.

Visually, the three subdials at the three lower cardinal positions produce what in the trade is called a «smiley face»: the axis of the two side subdials forms the eyes, the lower one the mouth. It's an intuitive reading, and it explains why this configuration has endured for decades without being replaced by more modern layouts.

The tricompax is associated with the great manual-winding calibers of the postwar era — Valjoux 72, Heuer 2444 and 3336, Universal Genève — and today is taken up both by manufacturers and by builders using derived ébauches. The date, when present, is often inserted into the window of the hours totalizer or in a separate window, as in the Monaco's Calibre 02, without altering the basic structure.