This year, a luxury Swiss watchmaker celebrates its 225th anniversary with several amazing new timepieces. The flagship model for the anniversary collection is La Esmeralda Tourbillon based on an archival pocket watch with a chronometer-rated Three Bridges tourbillon movement equipped with pivoted detent, tourbillon escapement and three gold bridges.
This original model was prized with a gold medal at the Universal Exhibition in Paris in 1889 and that same year also was awarded a bulletin at the Neuchâtel Observatory.
In recent years, the production of three-bridge tourbillons in Girard-Perregaux manufacture has become common and La Esmeralda Tourbillon is the latest three bridges tourbillon. Although this exceptional newcomer is not a pocket watch like its ancestor, its case was constructed to imitate the multi-layered original, which was hinged with front and back case covers, plus a second, hunter-type cover protecting the bridges.
Girard-Perregaux La Esmeralda Tourbillon is housed in an 18-karat pink gold case which aesthetically recalls the original La Esmeralda pocket watch, with a rounded bezel ring and a case-back ring slightly overlapping the middle case band.
The case of the new La Esmeralda measures 44mm in diameter and 14.55mm in thickness. It houses the Tourbillon with Three Bridges mechanical caliber GP09400 with automatic winding. This large 16-ligne movement, developed and manufactured in-house, takes up the entire case-band and features a 14.3 mm diameter tourbillon carriage and a 10.5 mm diameter balance wheel. The unique automatic winding system uses a rotor that is situated concentrically under the barrel and it is larger than in the archival Esmeralda, thus housing a longer mainspring. Consequently, the watch comes with the higher capacity of at least 60 hours of power reserve (the original mode had a 48-hour power reserve.)
The main difference when compared with the original model is the fact that the historic pocket watch was self-winding, while its heir features an automatic winding rotor which is mounted co-axially with the mainspring barrel.
The new watch has five screws on each bridge just like the original model. The surfaces of the arrows are mirror-polished, the edges are hand chamfered, the flanks are drawn and, in order to better catch the light, the arms of the bridges are carefully rounded by hand using a burnisher.
It took more than two weeks of work for Girard-Perregaux masters to finish by hand all the movement parts. Furthermore, it takes as long as one month for a watchmaker to complete a single movement.
Girard-Perregaux La Esmeralda Tourbillon (ref. 99275-52-000-BA6E) is constructed to resist water pressure up to 30 meters (100 feet). It is worn on a black hand-stitched alligator strap, fastened to the wrist by a pink-gold triple folding clasp. This exquisite watch will be produced in the limited quantities.