Introduced in 2016 as a fine example of a contemporary haute-horlogerie timepiece, the Datograph Perpetual Tourbillon from A. Lange & Söhne boasts the three grand complications dubbed in the name: a chronograph, a perpetual calendar, and a tourbillon. While each complication is a technical feat in itself, the greatest challenge lies not only in achieving the perfect interaction of the various highly complex mechanisms, but also in designing a well-organized and easy-to-read dial. It goes without saying that Lange accomplished this task with ease, translating the technical prowess into a harmonious layout. Comprising an equilateral triangle formed by the Lange outsize date in a framed twin aperture beneath 12 o’clock and the two subsidiary dials, the dial architecture is textbook example of clarity, despite the abundance of displays.
At this year’s Watches and Wonders, the German high-end luxury brand showcases the Datograph Perpetual Tourbillon Honeygold “Lumen.” Limited to 50 pieces, this introduction marks two premieres in the collection: Firstly, the introduction of Lange’s genuine 18-carat gold alloy and its luminous “Lumen” technology which brings all displays and functions to life in the dark. The Datograph Perpetual Tourbillon Honeygold “Lumen” is the sixth model of the limited “Lumen” edition, and, subsequent to the Zeitwerk “Lumen” launched in 2021, only the second model that combines the hardness and resplendence of honey gold with the luminous “Lumen” coating. Its case has a diameter of 41.5mm and boasts a height of 14.6mm.
To fully understand the technical complexity of the Datograph Perpetual Tourbillon Honeygold “Lumen,” one has to explore its three name-giving complications and many additional functions, such as a very precise moon-phase indication and typical Lange outsize date. First, there is the term Datograph that refers to chronograph, or more precisely, a flyback chronograph allowing quick consecutive time measurements because the three switching steps – stop, reset to zero and start – are executed with one single push of a button.
A special Lange development is the precisely jumping minute counter, which lives up to its name as it jumps to the next increment at the precise moment when the chrono seconds hand completes the 60th second. The functionality of the chronograph is complemented by a tachymeter scale for determining average speeds; it is located on the outer circumference of the dial made of coated sapphire crystal.
In addition, the watch offers a perpetual calendar with instantaneously switching displays. Based on the Gregorian calendar, it takes into account the different durations of the months, including leap-year deviations until 2100. Due to its high mechanical precision, the moon-phase display will only deviate from the true lunation by a single day after 122.6 years. The rapid-correction button at 10 o’clock can be used to simultaneously advance all displays by one day. Three correctors on the flank of the case make it possible to separately adjust the moon-phase display, the day of the week, the month and the leap year.
Last but not least, this timepiece features a one-minute tourbillon with a stop-second mechanism, which A. Lange & Söhne unveiled for the first time in 2008. This mechanism allows the tourbillon to be stopped at any time and the watch to be set to the nearest second, regardless of the angular position of the balance or the orientation of the tourbillon cage.
When the crown is pulled, a lever mechanism releases the stop lever, which moves the arresting spring towards the balance. The pressure of the spring immediately stops both the balance and the tourbillon carriage. When the crown is pushed back in, the balance and tourbillon are released and the watch immediately resumes running. Through the sapphire crystal case-back, one can admire the delicate and precise mechanics and the fascinating choreography orchestrated around the fourth wheel.
Thanks to the semi-transparent dial and the luminous coating of Lange’s Lumen technology, all displays and functions glow in the dark. The darker the surroundings, the more prominent the luminous elements. The hour and minute hands are inlaid with a luminous compound, while the chrono seconds hand is fully coated.
The hands of the subsidiary seconds, month, day and minute counters move above luminescent subsidiary dials. The luminous compound underneath causes the inscription on the circumferential dial ring with the minute scale and the tachymeter scale to glow too.
A special highlight for aficionados and a sight to behold is the luminous outsize date, first introduced on the Grand Lange 1 “Lumen” in 2013, which brings the ingenious disc mechanism to life in the dark. Ensuring that the display continues to light up immediately after the daily switching sequence was a considerable challenge. In typical Lange fashion, the solution was found: the tens’ cross and units disc are coated with a luminescent compound and printed with black numerals, so that the switching at midnight can be closely observed.
At the heart of the Datograph Perpetual Tourbillon Honeygold “Lumen” is the manufacture caliber L952.4, composed of 684 parts and assembled twice. The classic column-wheel chronograph is equipped with a freely oscillating Lange balance spring and a Lange balance wheel with eccentric balance weights, ensuring excellent rate stability over the entire 50-hour power reserve.
Calibrated to a frequency of 18,000 semi-oscillations per hour (2.5 hertz), it is accurate to one-fifth of a second. Through the sapphire crystal case back, one can admire the signature Lange hallmarks, like untreated German silver bridges, polished gold chatons, and blued screws.
Pricing is available upon request at A. Lange & Söhne.
To learn more, visit A. Lange & Söhne, here.
