A. Lange & Söhne blew away many watch connoisseurs at this year’s SIHH with its undisputed headliner, the Datograph Perpetual Tourbillon. But the Saxon haute horlogerie brand also rolled out a notable timepiece at the fair whose mechanical complexity comes in a slightly more understated but no less impressive package: the Richard Lange Jumping Seconds.
The newest model in the Richard Lange collection — introduced in 2006 and renowned for adding new, innovative facets to the classical scientific observation watch — the A. Lange & Söhne Richard Lange Jumping Seconds combines two complementary mechanisms: a one-second constant force escapement and an integrated jumping seconds function that displays the precise time in crisp, one-second intervals. Designed for optimal legibility as well as topnotch timekeeping precision, the watch features a large, blued steel central seconds hand that advances in exactly 60 steps per minute. A zero-reset mechanism, equipped with a multi-disk clutch, ensures quick and easy synchronization. The wearer simply pulls out the crown to send this seconds hand immediately to the zero position.
This mechanism, exceedingly rare in modern mechanical wristwatches, has its roots in classical horology: pocketwatches equipped with this function were used to determine measurements such as sidereal (solar) time and geographical longitude. Brand namesake Ferdinand Adolphe Lange developed an early version of this type of movement in 1867 and received a patent for it 10 years later.
The regulator-style dial (another nod to the history of chronometry, hearkening to the large central clocks with hours, minutes, and seconds on separate subdials that were used to “regulate” the time on watches) is made of solid, rhodium-colored silver. The overlapping subdials for the hours and minutes are shifted to the left and right, respectively, beneath the dominant seconds subdial. The dial’s other notable element is its power reserve indicator, a triangular window nestled above 6 o’clock inside the intersection of the hours and minutes subdial and just beneath the seconds subdial. When the watch’s movement is reaching the end of its 42-hour power reserve — 10 hours before it is depleted, to be precise — a red marker appears in the window (as seen below), gently reminding the wearer to rewind the watch.
The case is made of platinum and measures 39.9 mm in diameter and 10.6 mm thick. The sapphire crystals, one covering the dial and the other allowing a view of the movement from the caseback, rate a 9 on the Mohs hardness scale.
The technical complexity of the movement — Lange’s in-house, manually wound Caliber L094.1 — belies the smooth, elegant simplicity of the watch’s face. Its ingenious architecture distributes constant-force generation and the seconds jump to two wheel trains, but also allows them to interact. The first wheel train, extending from the mainspring barrel to the balance, uniformly delivers energy to the escapement in one-second intervals through a constant-force device. This mechanism serves a double function, compensating for the gradually waning force of the mainspring while simultaneously offseting possible torque fluctuations while the seconds jump is executed. The result is a constant amplitude across the entire span of the 42-hour power reserve range. The balance wheel, with eccentric poising weights, and the free-sprung balance spring, crafted in-house, contribute to a high level of rate accuracy.
The second wheel train is devoted to the seconds-jump function. Powered by the mainspring barrel, it converts the balance frequency of six semi-oscillations per second into one single step of the seconds hand. As in Ferdinand Adolph Lange’s original invention, this process is controlled by a five-point star attached to the escape-wheel arbor (a device visible, along with the escape wheel, through the caseback crystal; see below, lower left), which rotates on its own axis, together with the escape wheel, once every five seconds. Each second, one point of the star liberates the so-called flirt — a long lever, powered by the mainspring — which then executes an instantaneous rotation through 360 degrees, after which it is halted by the next point on the star. The 360-degree rotation, transmitted by the wheel train connected to the fourth-wheel arbor, moves the seconds hand to the next full-second marker. At the same time, fresh energy is transmitted to the remontoir spring of the constant-force escapement.
Controlling the zero-reset mechanism is a clutch on the fourth-wheel arbor consisting of three disks and a special, hand-shaped spring. The clutch disk in the middle is secured to the fourth-wheel arbor; in its closed position, the spring firmly presses the top and bottom clutch disks together, causing the clutch to immobilize the large seconds hand between the abrupt acceleration and deceleration cycles that occur every second in the normal operating mode. Pulling the crown activates a complex system of levers that block the balance with a stop spring and open the clutch, a sequence that separates the fourth-wheel arbor from the wheel train and allows almost friction-free zeroing. For this purpose, the zero-reset lever is pivoted against the heart cam, thus instantly returning the seconds hand to the 12 o’clock position. Pushing the crown home back in closes the clutch and releases the balance again to re-start the movement.
As Lange aficionados have come to expect, the movement, which consists of 390 parts, features hallmarks of traditional Glashütte watchmaking executed at the highest level, among them untreated German silver bridges, Glashütte waves, hand-engraved balance cock, and screwed gold chatons. The watch comes on a black, hand-stitched alligator leather strap with a prong buckle, made of platinum like the case. Strictly limited to 100 pieces, the A. Lange & Söhne Richard Lange Jumping Seconds is priced at 78,000 euros. Below check out a couple of shots I snapped of the watch at Lange’s New York City boutique during the recent Madison Avenue Watch Week.