Lederer Central Impulse Chronometer Limited Editions: Superlative Independent Watchmaking

Bernhard Lederer is a legend in the independent watchmaking pantheon, although you don’t hear as much about him as you might figures like Philippe Dufour, F.P. Journe (in the days before Journe became a renowned brand as much as leading man of exceptional watches) or the great Vincent Calabrese. But be that as it may, Lederer was there nearly from the beginning days of the Académie Horlogère des Créateurs Indépendants, the now revered organization that united the greatest watchmaking artisans–and nonconformist rebels–in the world of horology. This 18K white gold watch, the Lederer Central Impulse Chronometer, is a superb example of his aesthetic and technical brilliance, and just twenty-five examples apiece in each of the two dial colors will be produced. That each of these Central Impulse Chronometers will cost somewhat over $130,000 each is perhaps not surprising, given how much innovation and craft is entailed in their design and creation.

Getting basics out of the way, the watch presents a pleasing classical form with a dose of gigantism to it, being 44 millimeters in diameter, and 12.2mm thick. Not a small watch, nor a particularly thin one for a manual winder, but as we’ll discover, there are very good reasons for the watch being the size it is–first and foremost, to contain the masterpiece of watchmaking art that ticks inside of it like a finely fitted glove. And speaking of that mechanism, tantalizing aspects of its unique function and escapement reveal themselves through apertures in the centrally guilloche dial that deftly combines traditional design elements with modernistic touches in the bold large hobnail patterns, skeletonized leaf hands, and alluringly faceted elongated baton markers with an ever so slight oval profile. It speaks of taste, as well as cutting edge technology, and this watch gives both of them in like measure. Giving the large L-signed and interestingly knurled winding crown some turns brings the mechanism to life, and what do we see? The twin blued hands atop the adjacent apertures turn in opposing directions at the same time, creating some real visual intrigue! Some of the mechanism responsible for this can be seen inside the windows, but turning the Lederer Central Impulse over shows the full story, although to really get what’s going on takes quite a bit of study. There’s no ordinary, Swiss lever escapement in this thing–not at all!

(Lederer’s central impulse escapement is inspired by, yet builds on and improves, that of Breguet’s)

Building on an escapement first envisioned by Breguet—the so called “Natural Escapement“–and refined further by the late and great British watchmaker George Daniels (who of course, gave Omega the basis for their innovative three level Co-Axial Escapement for series production) the Lederer 9012 Caliber features two mainspring barrels, each with their own separate gear trains and escape wheels, which in alternating fashion both transmit energy directly to the balance wheel with a fascinating exchange, each advancing in an exacting cadence that takes place every five seconds, one first, then the other, and back again. While a very natural (hence Breguet’s term) and direct way to convey energy to the regulating organ, the natural escapement and its derivatives such as this are quite power hungry, owing to the extra wheels needed compared to more conventional alternatives such as the traditional Swiss lever, and there are some other technical hurdles present, as well. Despite the challenges of this simple-yet-tricky escapement muse, Lederer sought to increase efficiency of his central escapement as much as possible through usage of lightweight titanium in some components of the escapement as well as careful attention to the profiles of interacting surfaces, resulting in a mechanism with excellent resistance to shock, the capability for superb timekeeping precision, and a respectable power reserve of around 40 hours. Two constant-force remontoires on each of the gear trains assure a consistent flow of energy, irrespective of whether the 9012 movement is fully wound, or near exhaustion–another factor adding to the superb timekeeping of this inventive and beautifully conceived movement.

Beyond the mechanical ingenuity of what Bernhard Lederer has created with his fascinating take on the Breguet natural escapement, this Central Impulse Chronometer is also breathtaking to behold in terms of the finishing details, something we always hope for on such high executions, and definitely receive in this instance. Bridges are meticulously beveled on their edges and those ever-tricky intersecting points, steel components lavishly polished, and wheels given perfect finish not just on their visible surfaces, but teeth profiles as well–again, not just for cosmetic effect, but to achieve technical excellence in the workings of the mechanism. Nothing is left undone or untouched, yet the view is exciting and bold, as well as a mere showcase for pure watchmaking art. This movement is a real treat on every level, and is made even more remarkable for its size–note how it fully fills that large case–and the spectacular domed exhibition sapphire back. This is a stunning detail in itself, and further highlights the intricate little mechanical “city” and its fascinating operations, which encompass centuries worth of horological genius. You can almost get lost in it!