Deconstructed watch: A Lange & Söhne Minute Repeater Perpetual

Visitors to the A Lange & Söhne booth during this year’s Watches and Wonders fair were greeted by a massive, revolving facsimile of the German maker’s show stopper hanging from the rafters: the Minute Repeater Perpetual.

With its moving parts and accurate display, the electrically-driven model was impressive — but seeing the real thing here, in deconstructed form, gives a far better impression of the micro mechanical challenges faced in creating such a watch within a case measuring just 40.5mm across.

The movement alone contains 640 individual components, including 54 jewels, four of which are set into screwed gold chatons — a feature only found in top grade watch movements.

The hundreds of components are required to enable the smooth operation of the Minute Repeater Perpetual’s multiple functions, which comprise a striking mechanism that chimes the hours, quarters and elapsed minutes; a calendar that will remain accurate until March 1, 2100 and a moon phase display that so closely emulates the waxing and waning of the real thing that it will not need correcting for more than 122 years (assuming, in both cases, that the watch is not allowed to stop . . .)

Further features include an outsized date (requiring greater energy than a regular, small-sized version), a 24-hour time display and a leap-year indicator.

But it’s not just the functions of A Lange & Söhne’s first minute repeater, perpetual calendar watch that have impressed horophiles — it is also the way in which they have been executed to combine ease of use with reliability and robustness in a type of mechanism that is traditionally known to be both delicate and difficult to adjust.

A slide on the left flank of the platinum case is used to activate the chiming mechanism, which distinguishes between the hours, quarter hours and the minutes elapsed since the previous quarter by sounding them respectively with a low pitch, a double tone and a high pitch.

No fewer than 194 parts are needed to drive the repeater which, on the basis that its two gongs are capable of sounding any minute in a 12-hour time cycle, has a repertoire of 720 individual sequences.

The mechanism also boasts a “pause elimination” feature between the hour and minute strike, a safety device to prevent the chiming mechanism being activated when the crown is pulled out, and a system that stops the tiny hammers that create the chimes from rebounding on to their respective gongs.

Multiple assembly and disassembly operations are required in order to harmonise the various chiming components, attention to detail that is said to produce a “crystal clear sound” through the heavy, platinum case.

Should the watch be allowed to stop and the calendar need resetting, meanwhile, the task can be carried out using a single corrector rather than the multiple correctors commonly used on such mechanisms.

But as well as being technically impressive, the watch also stands out for its level of finishing, with the four-part, white gold dial being finished in black enamel with white gold “lesenes”, or “walls” bordering the four subsections.

Turning the watch over reveals an equally meticulous level of finishing to the hand — wound movement, which combines hand-engraving with blued screws and a three-quarter plate made from German silver decorated with lettering in black rhodium to complement the visible, black-polished hammers of the chiming mechanism.

The complexity of the Minute Repeater Perpetual means no more than 50 will be made during a production run that will continue for the next few years.

And, while the watch is likely to become a sought-after collector’s piece on the pre-owned market, anyone wanting to buy a new one will need to spend an estimated $750,000 — and then wait a while for A Lange & Söhne’s horological boffins to put it all together.