A. Lange & Söhne 1815 Rattrapante Perpetual Calendar

Threefold complication, twofold assembly, one-of-a-kind Lange

A. Lange & Söhne introduces a classic masterpiece, the 1815 RATTRAPANTE PERPETUAL CALENDAR, showcasing the harmonious blend of three intricate horological complications. This extraordinary timepiece unites the rarely seen and highly ambitious combination of a split-seconds, or rattrapante chronograph, with a perpetual calendar, now presented in a fresh interpretation. It boasts an elegant 18-carat white gold case complemented by a pink-gold dial. The exclusive 1815 RATTRAPANTE PERPETUAL CALENDAR is produced in a limited series of only 100 pieces.

In 2013, the introduction of the 1815 RATTRAPANTE PERPETUAL CALENDAR marked a significant milestone in the recent history of A. Lange & Söhne. Before this, the Saxon manufacturer had already created seven distinct chronograph calibers. This exceptional timepiece, powered by a specially crafted movement, skillfully combines three of the most intricate complications in a configuration rarely seen, all while maintaining the timeless and elegant design characteristic of the 1815 watch family. This remarkable watch excels in precision timing for both short and extended durations, setting new standards in both stopwatch functionality and calendar display.

Precision Timing to the Fraction of a Second:

The rattrapante, or split-seconds, function found in the 1815 RATTRAPANTE PERPETUAL CALENDAR presents one of the most formidable challenges in horology. In addition to performing the conventional functions of a chronograph, this intricate complication can measure intermediate times, compare different timings, and determine minimum and maximum values within a single minute. The manufacture caliber L101.1, with its balance wheel oscillating at six semi-oscillations per second, ensures that stopped times can be recorded with incredible accuracy down to one-sixth of a second. Further precision is achieved through the additional minute scale located around the periphery. The meticulous inner workings of the movement are visible through the sapphire crystal caseback, showcasing the classic two-column wheel mechanism that controls the measurement of both stopped and intermediate times. True to the A. Lange & Söhne tradition, this technical complexity is harmoniously paired with exceptional craftsmanship. All the exposed surfaces of moving parts are meticulously decorated with straight graining, while the beveled edges are polished to a sharp and flawless perfection, a skill only mastered by an experienced finisseur.

A calendar for perpetuity

While the rattrapante chronograph excels at measuring precise time intervals down to fractions of a second, the truly remarkable achievement of the perpetual calendar lies in its remarkable “long-term memory.” As the name suggests, this intricate and forward-thinking mechanism ensures the accurate display of date, day of the week, and month – every single day, spanning decades and even accounting for leap years. The need for correction in the calendar indications arises only once, on 1st March 2100. According to the Gregorian calendar rules, this leap year will be omitted.

The highly precise moon-phase display also demonstrates foresight in its programming. It faithfully mirrors the duration of the synodic orbit of the Earth’s satellite so closely that it would take an astonishing 122.6 years for the display to require a one-day correction.

Harmoniously arranged displays

The 1815 RATTRAPANTE PERPETUAL CALENDAR stands out not only for its technical prowess but also for the meticulously organized layout of its displays. Following the introduction of the DATOGRAPH PERPETUAL TOURBILLON in 2019 and the LANGE 1 PERPETUAL CALENDAR in 2021, it represents the third A. Lange & Söhne timepiece to feature an 18-carat pink gold dial, a warm and golden hue that elegantly contrasts with the cool white gold case. The dial embodies the essence of the watch family, named after the birth year of Ferdinand Adolph Lange, through its traditional railway-track minute scale, Arabic numerals, and the harmonious arrangement of the four subdials.

The various displays of the perpetual calendar and rattrapante chronograph pay homage to the classic aesthetics of earlier Lange pocket watches. The two pairs of combined calendar indications are thoughtfully positioned at 3 and 9 o’clock. The left subdial showcases the date and day of the week, while the right subdial indicates the month and leap year. Sharing an auxiliary dial with the subsidiary seconds at 6 o’clock, the moon-phase display adds an expressive touch of color. At 12 o’clock, the minute counter and power-reserve indicator find their place. The shorter gold hand within the inner circle signals when it’s time to replenish the movement’s power through the winding crown, while the longer blued steel hand provides information about the elapsed minutes.

Manufacture calibre L101.1

The manually wound movement L101.1 embodies a harmonious fusion of traditional design and engineering elements, boasting an impressive total of 631 individual components. Within this intricate assembly, the perpetual calendar mechanism alone comprises 211 parts, while an additional 206 components contribute to the rattrapante-chronograph function. Ensuring precise timekeeping, a screw balance, driven by an in-house developed and manufactured balance spring, maintains high rate stability. A hallmark of Lange’s quality, the movement also features screw-mounted gold chatons, blued screws, a meticulously crafted whiplash precision index adjuster, and a finely hand-engraved balance cock, all visible through the sapphire-crystal caseback. The meticulous finishing of this movement, assembled with care twice over, exemplifies A. Lange & Söhne’s unwavering commitment to excellence, evident in every intricate detail.

 “With three classic complications, the manufacture calibre L101.1 is one of our most complex movements. Each one in itself already constitutes a technical feat; when combined, they represent a far greater challenge. For our designers and our watchmakers in equal measure, since the tweaking and tuning process of all mechanisms requires an exceptionally high degree of dexterity and technical expertise,” explains Anthony de Haas, Director of Product Development at A. Lange & Söhne.

Three versions

The dimensions of the recently introduced 1815 RATTRAPANTE PERPETUAL CALENDAR remain consistent, featuring a case with a diameter of 41.9 millimeters and a height of 14.7 millimeters. In addition to the limited edition 1815 RATTRAPANTE PERPETUAL CALENDAR in white gold with a pink-gold dial, which is limited to 100 pieces, the model is also available in two other elegant variations: one with a platinum case and argenté dial and another with a pink gold case and argenté dial.