With the Rattrapante 1815 Perpetual Calendar, launched in 2013, A. Lange & Söhne brings three of the most complicated watchmaking complications to the stunning classic design of the 1815 series. The rare and challenging split-seconds chronograph with perpetual calendar is now presented in a new livery, featuring an 18-carat white gold case with a rose gold dial and limited to 100 pieces. This is the third watch from A. Lange & Söhne to boast a dial in this color, which is highly sought after by collectors, and joins existing models in platinum and rose gold with Argenté dial.
The rattrapante function is considered one of the most ambitious in the world of high-end horology, as it is capable of measuring intermediate and comparative times as well as determining minimum and maximum values within time intervals. one minute in addition to the classic chronograph functions. . When the balance wheel of the L101.1 production caliber beats with six semi-oscillations per second, the dwell time can be recorded with an accuracy of 1/6 of a second. Thanks to the additional graduation on the peripheral minute scale, these parameters can be easily read.
While the rattrapante chronograph excels in short-term measurement, the perpetual calendar is the long-term champion. The complex mechanism ensures that the date, day of the week and month are displayed accurately – every day, for decades, even counting leap years. The indications on the calendar are only corrected for one day but not until March 1, 2100 when leap years will be omitted according to the Gregorian calendar.
The highly accurate moon phase display has also been programmed with longevity in mind. It so closely simulates the duration of the Earth satellite’s synchronous orbit that it takes 122.6 years for the display to be corrected in one day.
It goes without saying that the German luxury manufacturer presents these functions in a most classic design, conveying the classic aesthetics of the classic Lange pocket watch in line with the 1815 collection. Two pairs of combined calendar indicators are arranged at the 3 and 9 o’clock positions. The left sub-dial displays the date and day of the week, the right the month and leap year. Sharing a sub-dial with the subsidiary seconds hand at 6 o’clock, the moon phase display provides an expressive, colorful highlight. The minute counter and power reserve indicator are located at 12 o’clock. The shorter gold hand on the inner circle indicates when new power needs to be supplied to the movement via the winding crown. The longer hand made of blued steel conveys information about the number of minutes stopped.
The Rattrapante 1815 Perpetual Calendar, measuring 41mm in diameter, is powered by the L101.1 manual-winding movement. A feast for the eyes and a microscopic mechanical gem, it features an impressive total of 631 individual parts. The perpetual calendar mechanism alone requires 211 components, with an additional 206 for the rattrapante-chronograph mechanism. Screw balancing, driven by an in-house developed and manufactured balance spring, ensures stability at high speeds.
Typical Lange quality markers such as screwed gold chatons, blued screws, intricate precision index adjusters and hand-engraved balance pins are all visible through the sapphire crystal case back. The finishing of the movement, which is assembled twice as compared to all Lange movements, demonstrates the brand’s high standards in every detail.
Particularly pleasing to connoisseurs is the display of the chronograph mechanism, with a classic two-column wheel gearbox used to control the measurement of stop and intermediate times. As is typical for A. Lange & So, technical complexity goes hand in hand with a high level of craftsmanship. The top surfaces of all moving parts are decorated with straight grain lines while the peripheral chamfered edges are polished. Only an experienced finisher has the skill to polish bevels to perfectly sharp and flat.
“With three classic complications, the manufacture caliber L101.1 is one of our most complex movements. Each in itself constitutes an engineering feat; when combined, they represent a much greater challenge. To our designers and watchmakers in equal measure, as the process of fine-tuning and adjusting all the mechanisms requires an exceptionally high level of craftsmanship and technical expertise,” Anthony de Haas