A. Lange & Söhne: Zeitwerk Minute Repeater

Presented in 2015, the Zeitwerk Minute Repeater is the world’s only watch that combines a mechanical jumping numerals display with a decimal minute repeater. The complicated timepiece – its assembly alone requires several months – has so far been available only in platinum. Five years after its debut, it now comes in a limited 30-watch edition in white gold with blue dial. 

The Zeitwerk Minute Repeater features a totally new interpretation of the classic complication. Its striking mechanism – it sounds ten-minute intervals instead of quarter-hours with double strikes – is a convincing logical complement to the “digital” display of the time. 

As soon as the striking mechanism is activated with the repeater pusher at 10 o’clock, it sounds the time as indicated on the dial. One hears what one sees. And one sees what one hears. At 7.52, for instance, the gong hammer on the left strikes the low-pitched gong seven times, once for every elapsed hour. Then, five double tones are struck for the elapsed ten-minute intervals, followed by the right-hand hammer with two high strikes, one for each elapsed minute. 

In the development of the striking mechanism, Lange’s engineers relied on the basic principle of the jumping numerals mechanism with which the time is displayed by an hour ring and two minute discs. This configuration makes it possible to sample the number of strikes to be executed – separately for the hours, ten-minute intervals and minutes – directly on the snails that are connected to the mechanical display elements. At the same time, enlarged sampling surfaces enhance the reliability of the striking mechanism. This assures that the acoustic time always corresponds to the displayed time. 

PUSHER INSTEAD OF SLIDE

The Zeitwerk Minute Repeater features a unique pusher mechanism for triggering the repeater. Because the power for the striking mechanism is delivered by the mainspring barrel, there is no need for a slide – common in minute repeaters – to tension a separate spring. The absence of a large lateral opening in the case eliminated a source of acoustic disruption, thus improving the sound quality. And since a pusher, unlike a slide, can be sealed, the watch is water-resistant to as much as 3 bar. 

FINESSE IN DETAILS

The Zeitwerk Minute Repeater stands out with a number of refined technical features that in particular optimise its operation. 

Since a switching action could cause mechanical conflicts while the repeater is running, the numerals discs are prevented from incrementing until the repeater sequence has ended. This can take up to 20 seconds. The delay also assures that the digitally displayed time and the acoustic time are always the same. 

For the same reason, the crown cannot be pulled while the striking mechanism is active. The actuation of the repeater pusher uncouples the wheel train of the winder from the ratchet wheel that drives the striking mechanism. This prevents the wheel train of the winder, including the crown, from rotating during the repeater sequence, which would result in an unnecessary loss of energy. 

Finally, when the power reserve drops to less than twelve hours, the striking mechanism can no longer be activated. This assures that the repeater sequence is always executed in full: The watch will not stop unexpectedly before the strike sequence has been completed. On the power-reserve indicator, the 12-hour mark is identified with a red dot. 

The new Zeitwerk Minute Repeater comes in a 44.2mm white-gold case with a matching deployant. The deep-blue dial in solid silver contrasts with the rhodiumed German silver time bridge. A blue hand-stitched leather strap highlights the elegance of the timepiece. Limited to 30 watches, this edition is available exclusively in the  A. Lange & Söhne boutiques at the price of € 449.000.