Lange Zeitwerk: why a mechanical watch uses jumping numerals

A. Lange & Söhne · Zeitwerk

The model in detail

The most engaging Zeitwerk moment comes at the change of the hour: the digital display changes mechanically, without a screen. Three discs show hours, tens and units of minutes; small seconds retain their familiar continuous motion.

Simple reading conceals a difficult task: the discs need switching energy, while the balance needs a steady supply. A constant-force mechanism separates these demands and establishes the one-minute switching rhythm. This makes Zeitwerk interesting as a machine as well as an unusual dial.

L043.6 comprises 451 parts and runs at 18,000 vibrations per hour. Two mainsprings provide the stated 72-hour reserve. The upper indicator shows when winding is due. A pusher near four o’clock independently advances the hour display, useful when changing time zones.

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Reference 142.025 uses 950 platinum, with a diameter of 41.9 mm and thickness of 12.2 mm. This is a substantial case: a photograph cannot settle weight or comfort on an individual wrist. The manufacturer specifies 3 bar water resistance and price on request.