During the 1970’s, with the rise of quartz, Girard-Perregaux was one of the first Manufactures to take up the challenge of a return to traditional mechanical timepieces, and undertook the remaking of twenty pieces of Constant Girard’s masterpiece: the famous Tourbillon with three gold Bridges pocket watch.
After 1500 hours of work, the number 1 is presented. One of the challenges was to relearn forgotten techniques and gestures.
For example, the watchmakers had to hand-finish the parts with files and burnishers as no machinery was capable of working on these smaller parts with tolerances of one hundredth of a millimeter!
The detent mechanism of the Tourbillon features a stone of only 0.04 mm!
The rectangular section of the detent measures, at its thinner end, only 0.2 mm in height and 0.1 mm in width!