A. Lange & Söhne

A. Lange & Söhne incorporated two of the most sophisticated horological complications in the MINUTE REPEATER PERPETUAL. A newly developed, manually wound movement breathes life into this rare and ambitious combination of a minute repeater with a perpetual calendar. The elaborately, artisanally finished timepiece boasting an enamel dial crafted in-house comes in a 950 platinum edition, limited to 50 pieces.

With the MINUTE REPEATER PERPETUAL, A. Lange & Söhne once again launches a watch with a minute repeater, this time pairing it with a perpetual calendar. Each one of these complications alone represents a technical feat in itself, the combination of the two, however, poses an even greater challenge. This holds true for the engineers as well as the watchmakers, since the precise tuning and harmonising of all the mechanisms requires a superior degree of technical expertise and craftsmanship.
 
Classic minute repeater with special features 

When the slide integrated into the left-hand case flank is actuated, the chiming mechanism strikes the hours, sounding at a low pitch, the quarter hours with a double tone, and the minutes that have elapsed since the last quarter hour with a higher-pitched tone. The impressive duet delivered by two differently tuned gongs comprises a repertoire of 720 different sequences – one for every minute in the twelve-hour cycle. The sapphire-crystal caseback reveals the orchestrated movements of the gong hammers and the gongs, resulting in their melodious sound. An ingenious system of precisely choreographed racks, snails, levers, and wheels controls the 194-part mechanism. 

To optimise the operation and functionality of the classic minute repeater, the striking mechanism was enhanced with further intricate devices, among these the pause elimination feature. It skips the pause between the hour and minute strike when no double tone must be struck for the quarter hours in the first 14 minutes after the top of the hour. To prevent damage to the chiming mechanism, it was also equipped with a safety device so that the minute repeater cannot be activated while the crown is pulled. Consequently, the crown cannot be pulled when the chiming mechanism is active. Finally, the patented hammer blocker causes the hammers to dwell in their home position for a fraction of a second after the gongs have been struck. Thus, the re-bounding hammers cannot bounce and strike the gongs again.

The art of crystal-clear sound

Just like all Lange watches with a striking mechanism, the MINUTE REPEATER PERPETUAL is designed to superb acoustic quality standards and has a unique timbre. A lucid, clear, and reverberant sound is assured by the hand-tuned gongs that harmonise perfectly with the acoustic characteristics of platinum, the case material. The completion of a minute repeater is highly elaborate; it also calls for acute hearing and extreme dexterity. All components are carefully harmonised with one another by a Lange master watchmaker. This requires adapting, multiple disassemblies, reworking, reassembly and finally testing. As far as the hammers are concerned, the key issues are material, shape, size, weight, and hardness – and above all, just like with a piano, strike. 

“Thanks to the development of a new movement, we were able to work towards a perfect sound experience, right from the start ‒ just like with our other models featuring a striking mechanism: the ZEITWERK MINUTE REPEATER, the RICHARD LANGE MINUTE REPEATER or the GRAND COMPLICATION. Combined with the acoustic properties of platinum, we succeeded in achieving a singular sonority and intensity of sound,” explains Anthony de Haas, Director of Product Development at A. Lange & Söhne. 

Perpetual calendar with Lange outsize date

While the minute repeater chimes the time in the here and now, the technical virtuosity of the perpetual calendar will persist into the distant future. Across decades, the mechanism will assure the precise display of the date, day of the week and month, even taking into account the leap years. The calendar indications must only be corrected by one day but not until 1 March 2100; according to the rules of the Gregorian calendar, the leap year will then be skipped. 

This also applies to the moon-phase display that so closely emulates the duration of the synodic orbit of the earth’s satellite that it would take 122.6 years for the display to be corrected by one day. The mechanism is highly sophisticated yet excels with its ease of operation: in typical Lange manner, all calendar indications can jointly be advanced with one single corrector.

An eye-catching detail of the timepiece ‒ the enamel dial

The technical sophistication of this multiple-complication watch is reflected in the high-quality artisanship of the four-part dial. Made of white gold and filled with black enamel, it is crafted in the A. Lange & Söhne manufacture in a time-consuming procedure. The immaculate, glossy black surface offers the displays and the characteristic Lange outsize date an elegant stage, providing a contrasting backdrop, thus assuring excellent legibility. The subsidiary dial at 9 o’clock accommodates the day-of-week and the 24-hour displays while a second one located at 3 o’clock is graced by the month and leap-year indications. A third subsidiary dial at 6 o’clock showcases the small seconds and the moon-phase display: both moons in 750 gold are surrounded by more than 100 hand-engraved stars.

This exceptional timepiece exhibits a further salient detail: all four dial sections are embellished with a circular lesene, a fine border in white gold. On the main dial, it runs between the outsize date and the Roman numerals; on the subsidiary dials, the lesenes separate the inner display sections from the outer ones.

Artisanally finished new manufacture calibre

The sapphire-crystal caseback provides fascinating insights into the technical complexity and the high degree of artisanal finishing of the newly developed Lange manufacture calibre L122.2. Whether clearly visible or concealed, all 640 parts of the manually wound movement address all expectations that are associated with A. Lange & Söhne’s craftsmanship. The aesthetic highlights include the balance cock that is engraved with a free-hand technique, with the whiplash spring mounted on top. The lateral setscrew assures the precision regulation of the interaction between the escapement and the oscillation system. The three-quarter plate made of untreated German silver is decorated with black-rhodiumed engravings. Four screwed gold chatons adorn its grained surface.

Whereas the greater part of the repeater and the perpetual calendar mechanisms lies concealed below the dial, the most important elements of the striking mechanism – the two manually bent gongs framing the movement and the two gong hammers – are resplendent in their beauty. The hammers provide an additional focal point: they are elaborately finished with black polish, a technique that involves a considerable amount of manual work. It ensures that incident light is reflected in merely one single direction. Viewed from one perspective only, the surface is jet black, yet seen from all other angles, it appears to have a mirror-like gloss. The barrel bridge, the centrifugal-governor bridge and the gong hammer bridges are adorned with solarisation, creating a visual entity. The most dynamic component of the movement, the centrifugal governor is mounted in an overhung position, making it almost silent when operational. It rotates at a speed of more than 2,000 revolutions per minute when the striking mechanism is running. This guarantees the uniform cadence of the strikes.

The Lange manufacture calibre is equipped with a screw balance and a freely oscillating balance spring crafted in-house. Decorated with solarisation, the mainspring barrel delivers a maximum power reserve of 72 hours.