Anthony de Haas, Director Product Development, of the Glashutte-based A. Lange & Söhne reveals in a chat with Hiren Kumar Bose how issues regarding the architecture and construction of the Manufacture’s most complex watch, Tourbograph Perpetual “Pour le Mérite” were resolved.
With a chronograph, a perpetual calendar with a moon-phase and a tourbillon in the Tourbograph Perpetual “Pour le Mérite”, can we say it is the most accurate watch ever manufactured by A. Lange & Söhne?
It is one of five A. Lange & Söhne timepieces with a fusée-and-chain transmission. We do not classify our models with this mechanism different from our other watches. But, indeed, the fusée-and-chain mechanism is one of the most efficient complications for assuring constant torque delivery across the entire power-reserve period. Via the fusée connected to the mainspring barrel with a 636-part chain, the power of the mainspring is delivered to the movement with constant torque thanks to the efficient way in which the principle of levers is harnessed. A planetary gear system inside the fusée assures that the flow of power from the mainspring barrel to the going train is not interrupted while the watch is being wound. Especially for highly complicated timepieces with several mechanisms, it is a challenge to assure a high rate stability and accuracy.
Integrating a perpetual calendar to orchestrate the interaction of the complex mechanisms in such a way that mechanical conflicts or unwanted energy losses could be prevented wasn’t that a challenge. How was it overcome? Did it require redesigning of the basic calibre without increasing the height of the movement?
It is worth mentioning the enormous design effort invested in the watch. Despite its five complications, it is surprisingly a wearable watch. To save space we built the perpetual calendar around the tourbillon. This required a complete redesign of the basic calibre. Like in every movement with a multitude of complications, the main challenge was to organise the interaction of all mechanisms by ensuring an intelligent energy management.
Of the 684 parts in the new L133.1 manufacture calibre, no fewer than 206 constitute the perpetual calendar. What is the share of the other movements?
Similar to the perpetual calendar, about one-third of the total number of components are part of the chronograph-rattrapante. Besides, only the tourbillon mechanism is made of 84 parts. And, by the way, if we would count each of the 636 components of the little chain, the total number of parts of this timepiece is 1319.
Building a calendar module around the tourbillon without affecting the space around is a Herculean task. How were you able to achieve the impossible?
In this project, the perpetual calendar mechanism had to be built around the tourbillon. Consequently, only about two-thirds of the movement surface was available, and this necessitated a redesign of the basic calibre. At the same time, the developers did not want to noticeably increase the height of the movement – a challenging task for our movement developers.
The complex finishing technique using black polish on the Tourbillon Bridge integrated into the dial has been used on a curved surface for the first time in this watch. Did it prove to be a challenge for the finisseurs?
Indeed, this finish technique imposes new challenges on the finisseurs because for the first time ever at A. Lange & Söhne, this complex finishing technique is being applied to a curved surface. And by the way, not only to the finisseurs, but also to the tool makers who supported them in creating made-to-measure holders and tools for this work.
Made of 684 components is it the most complex movement of the collection to date?
It is an exceptional timepiece that features a unique combination of five horological complications. Therefore, one could call it indeed a grand complication. However, we decided not to call it a Grand Complication because we already have one that is still in the delivery process. This timepiece, consisting of 876 individual components, is the most complex one till date.
With just 50 pieces to be made do tell us how long does it require to make one, the process involved and how many man hours invested?
The watch is being crafted in a limited edition of only 50 platinum-cased timepieces. The finish of the manufacture calibre complies with the highest standards of Saxon watchmaking artistry. The assembly of this complication takes several weeks.
Costing half a million dollars, when it is put on sale, will it attract the distinction of being the costliest watch from the brand
A. Lange & Söhne follows a classical approach to fine watchmaking that seeks to combine ingenuity, craftsmanship, precision, and aesthetics at the highest possible level. The watch is faithful to our codes while taking our expertise in horological complications to new heights. I, therefore, don’t think that it attracts people who just look for the most expensive piece around, but rather watch connoisseurs who really appreciate our fine art of watchmaking.