Calatrava “Squelette” Self-Winding
Exceptionally transparent elegance.
As it turns 40, nothing spotlights the distinctiveness of the ultra-thin self-winding caliber 240 movement as aptly as the skeletonized Calatrava that has been a part of Patek Philippe's regular collection since 2008. As of 2017, the new Calatrava "Squelette" Ref. 5180/1R in 18K rose gold 5N showcases the extremely rare craft of skeletonization alongside magnificent engravings to imbue the elegant mechanism with enigmatic sensuousness. The aesthetic appeal and transparency with which the caliber 240 SQU keeps track of time makes it a miniature opus of kinetic art. Its plate and bridges are pierced to the maximum extent possible to create a seductive view without compromising the reliability and functional integrity of the movement. The work involved requires not only artistic flair and a steady hand, it also calls for the skill of the watchmaker who knows exactly where the limits of skeletonization lie. The plate is open-worked even above the barrel, exposing the coiled mainspring beneath the pierced contour of the Calatrava cross, which has been a registered Patek Philippe trademark for over one hundred years. It takes more than a week to create the filigreed transparency of the movement, but at that point, the project is far from over. The next steps take place on the workbench of the engraver who further refines the watch with his artisanal skills. He invests more than 130 hours to decorate the remaining structures with vivid arabesques and volutes. The "Patek Philippe Genève" brand signature is engraved on the remaining parts of the barrel frame around the Calatrava cross, which itself is also decorated. Additionally, the "PP" logo of the Patek Philippe Seal is making its first appearance of the 22K gold minirotor. In the end, the entire skeletonized movement chassis is plated with rose gold and then polished to match the case and bracelet. Now decidedly a work of art, the self-winding caliber 240 SQU is framed by a movement holder ring in 18K rose gold 5N. The ring itself is also skeletonized down to 12 spokes that serve as hour markers.
The great effort involved in skeletonization and engraving does not infringe any horological principles as evidenced by the rate parameters of the completed watch. With a tolerance of -3 to +2 seconds per day, its rate accuracy complies with the strict directives of the Patek Philippe Seal. This is due not least to the Spiromax® balance spring made of high-tech Silinvar®. Its purple iridescent shimmer is readily visible in the totally skeletonized movement.
The caliber 240 SQU is accommodated in a round rose-gold Calatrava case which is reduced to a narrow frame and places emphasis on the movement. With its large-format sapphire crystal glass and caseback, it assures total transparency yet offers optimized protection and water resistance to 3 bar (30 meters). The watch is worn on a supple bracelet in 18K rose gold, safely secured with a fold-over clasp.