No review of SIHH 2017 could be complete without a resounding mention of A. Lange & Söhne. Not only because of the passing of Walter Lange, the great-grandson of the founder, and a luminary in the luxury watch industry by his own hand, but also because of the extraordinary timepieces introduced this year at Geneva by the brand that bears his name. Without question, A. Lange & Söhne has established itself as one of the greatest mechanical watch manufacturers of the 21st Century.
In typical German style, however, the brand has always abstained from hype and marketing hyperbole, instead opting to let its timepieces do all the talking. This principle was upheld at SIHH 2017, where the brand’s newly unveiled Tourbograph Perpetual Pour le Mérite truly nailed their colours to the mast.
As the name suggests, the Tourbograph Perpetual features the tourbillon regulator with a fusée-and-chain transmission (more on that in a minute) and a split-seconds chronograph like the original model from 2005. Now, however, a perpetual calendar has been engineered into the mix as well. Lange of course makes it look easy, but the reality is anything but. To really understand this incredible timepiece it’s best to break it down complication by complication.
The Perpetual Calendar
The perpetual calendar complication alone is comprised of some 206 parts and incorporating it into the Tourbograph movement required a complete redesign of the original base calibre to ensure everything nestled just right. Despite the challenges faced, however, the legibility of the many indications on the dial has not been compromised in any way. In total there are 3 sub-dials, each of which feature two indications. At 12 o’clock is a classical moon-phase indication (accurate for the next 122.6 years), with the date printed on the periphery and indicated by a white gold hand. At 3 o’clock we find a highly intuitive months and leap-year indicator, while over at 9 o’clock the sub-dial serves as both a 30-minute counter for the chronograph and indication of the day of the week for the calendar. To ensure there is no confusion, the chronograph hand is in blued steel, whilst the day indicator is in white gold.
The Split-Seconds Chronograph
Next up is another favourite complication amongst collectors; the rattrapante (split-seconds) chronograph. As you know a standard chronograph allows the operator to measure elapsed intervals of time. A split-seconds chronograph take this concept one step further and allows also for the simultaneous measurement of intermediate intervals of time. Essentially what this means is that the chronograph is equipped with two central-second hands. When the chronograph is started they operate in unison, one directly beneath the other. However, if you press the split-seconds pusher at 10 o’clock, one hand will stop immediately whilst the other will continue – allowing you to measure an intermediate interval of time. Activate the pusher at 10 o’clock again and the stopped hand instantly springs forward to re-join its companion (hence the rattrapante moniker – which means ‘catch up’ in French.)
Pour le Mérite
/ The Fusée-and-Chain
Finally, we come to the least visible, although arguably the most impressive technical aspect of the Tourbograph Perpetual; the constant-force Fusée-and-Chain. Comprised of a cone-shape pulley linked to a chain coiled round the barrel, the role of this complex little device is to ensure that the force delivered by the barrel to the escapement is as constant as possible. The idea here is to equilibrate the torque that is received by the escape wheel over the whole length of the mainspring’s power reserve from fully wound to totally uncoiled, thus increasing the accuracy and effectiveness of the movement.
The effect can be illustrated with the situation of a cyclist who faces a long ascent, like Mount Ventoux. At the outset, the cyclist still has plenty of energy (like the fully wound mainspring). He can choose a small sprocket (small radius) on the rear-wheel cassette. After several exhausting uphill kilometres, the power of his legs begins to decline (like the power of an unwinding mainspring). He can equalise this by selecting a larger sprocket.
The Fusée-and-Chain is made up 636 parts, with the smallest radius of 2.97mm and the largest radius of 4.46mm. Yet the watch still offers a power reserve of 36 hours, which is exceptional given the number of complications.
Presented in a platinum-only 43mm x 16.6mm round case, the Tourbograph Perpetual is just stunning to behold and looks and feels more modern than its predecessor. The watch is fitted with a hand-stitched, black alligator leather strap complete with deployant buckle in platinum, adding the finishing touch to this sophisticated but subdued aesthetic. Without a doubt a grail watch for collectors, only a mere 50 pieces will ever be produced.