We all know the Datograph, THE most iconic chronograph of A. Lange & Sohne – and clearly, one of the most desirable chronographs of the actual production (if not one most desirable watches of the actual production). We also know the more complicated edition, the Datograph Perpetual, that the brand renewed last year, with its stunning grey dial and a QP. For the 2016 edition of the SIHH, it’s a pure horological marvel that the Saxonian manufacture will reveal, as not only you’ll find the hyper-nice chronograph movement, with the extra-perpetual calendar AND now with a tourbillon, discreetly located on the movement side. Here is the über-Datograph, you name it: the A. Lange & Sohne Datograph Perpetual Tourbillon.
This new A. Lange & Sohne Datograph Perpetual Tourbillon combines the best of Lange in a single watch: a Datograph with a perpetual calendar and a Tourbillon regulator that is, in order to respect the purity of the dial, located on the movement side – and thus, leaving the pleasure of seeing the ballet of the balance wheel and the rotating cage only to the owner and a few insiders. The best: this one comes with a black dial, in a platinum case and still is very well proportioned. However, don’t think that A. Lange & Sohne just add a tourbillon to the Datograph Perpetual… As the brand loves to say: “Never Stand Still”. The story is a bit more complicated.
In the A. Lange & Sohne nomenclature, Datograph designates a column-wheel chronograph with a precisely jumping minute counter, a flyback function and the typical Lange outsize date. Here, in the A. Lange & Sohne Datograph Perpetual Tourbillon, the base of the movement used in the normal Datograph, the calibre L951.6, is re-issued to create the new movement. Meaning that the base is the same – same gear train, same position of the sub-counters (slightly below the center of the watch), same chronograph mechanism (meaning that the superb layout of the movement is also present here, with the same levers, gears and springs visible through the caseback). Even with the extra-complications (QP + Tourbillon), this new edition remains close in terms of size to a Datograph (41.5mm x 14.6mm vs 41mm x 13.1mm).
Just like the previously introduced Datograph Perpetual, this new A. Lange & Sohne Datograph Perpetual Tourbillon features a perpetual calendar, displayed first via an outsize date at 12 (with numerals in white on a black background, to match with the black sub-counters – thus different from the “Panda” style of a normal Datograph Up/Down). Then, the perpetual calendar also uses the sub-counters: the one on the left displays the month and the leap year and the one on the right display the day of the week and a day-night indicator. However, those who know the Datograph Perpetual will have noticed that the layout is different in the A. Lange & Sohne Datograph Perpetual Tourbillon. Here, the leap year and the day/night indicator are integrated IN the sub-counters and not in another small sub-dial overlapping these main sub-counters. The new one thus feels more balanced and maybe a bit easier to read. Finally, the moon phases are classically displayed in a sub-dial at 6.
Another novelty is the appearance of a power reserve indicator – called the Up/Down or Ab/Auf feature at A. Lange & Sohne. Even if this power reserve is one of the key features of the classical Datograph Up/Down, it is absent of the Perpetual edition. In order to keep the dial legible, Lange decided to bring back this feature in the Datograph Perpetual Tourbillon but not to display it in a sub-dial. Instead, it comes in a discreet arched-window between 9 and 10, on the inner flange, next to the tachymeter scale.
The main novelty of this A. Lange & Sohne Datograph Perpetual Tourbillon is of course… its tourbillon. The Saxonian Manufacture however made the right choice not to show it on the front, in order to keep the clean, refined but also more toolish look of the classical Datograph. It could almost be seen as an understated ultra-high-end piece. This one-minute tourbillon features the in-house free-sprung balance-wheel with eccentric poising weights. Due to the more energy-consuming regulating organ, the power reserve is a bit shorter here (going from 60 hours to 50 hours… a spec that remains comfortable). For the first time in a Lange tourbillon with chronograph, the balance beats at a rate of 18,000 instead of the conventional 21,600semi-oscillations per hour. This corresponds to a frequency of 2.5 hertz. Consequently, stopped times can be displayed with an accuracy of one-fifth of a second (meaning that the second hand REALLY beats according to the markers – something that is not always the case in chronographs…).
The tourbillon also feature the patented stop-seconds mechanism that brings the balance-wheel inside the tourbillon cage to a standstill when the crown is pulled. This allows the watch to be set with one-second accuracy – a same mechanism also exists in the 1815 Tourbillon (however, with an extra zero-reset complication). As usual with the brand, the the 729-part calibre L952.2 is finished with extreme attention to detail and shows a superb depth. The cage of the tourbillon is opened to better observe its ballet.
The A. Lange & Sohne Datograph Perpetual Tourbillon will be made in a limited run of only 100 pieces. Price: 295,000 Euros. More details on www.alange-soehne.com.