Since the time can be read quickly, the wearer can then turn his attention down to the bottom of the dial, where the two black-polished steel hammers for the minute repeater are readily visible on either side of the seconds subdial. When the pusher at 10 o’clock is pressed, the hammers strike the gong which encircles the dial. The hours hammer, with a lower pitch, is on the left side; the higher-pitched minutes hammer is on the right. Ten-minute intervals are signaled via a “double tone”: the higher pitch is hit with the lower one immediately following. The maximum duration it takes to strike out the time (at 12:59) is approximately 20 seconds.
The Zeitwerk Minute Repeater has several practical safety mechanisms to preserve the integrity of the watch. In addition to a stop-seconds function to make for easier, more accurate time setting, the crown is protected so that it cannot be tampered with while the striking mechanism is activated. Once you press the minute repeater’s pusher, the winding train is uncoupled from the ratchet wheel. This saves energy and protects the winding train from harm. Furthermore, the discs for the jumping hours and minutes will not move while the chime is ringing: the time you hear will always be consistent with the time you read off the dial.
The manually wound watch has a 36-hour power reserve. The chiming mechanism cannot be engaged in the final 12 hours of that period, since it would drain too much energy from the barrel and jeopardize consistent timekeeping. When the power-reserve indicator’s hand moves past the red dot on its railroad track, the minute repeater can no longer be activated.
The Zeitwerk Minute Repeater has an in-house Lange movement, Caliber L043.5. It has a constant-force Swiss lever escapement. In Glashütte style, there is a three-quarter plate (visible through the caseback) which is made of German silver. The movement, which is 37.7 mm in diameter and 10.9 mm high, is entirely hand decorated and assembled. The balance cock is also engraved by hand. The balance is shock resistant and uses eccentric weights for fine adjustment. It beats at 18,000 vph. All told, the movement has 771 components, including 93 jewels.
The Zeitwerk Minute Repeater is cased in platinum. It is 44.2 mm across and 14.1 mm thick. There are nonreflective sapphire crystals on both the front and back. It has a hand-stitched black alligator strap with a platinum deployant buckle.