For your consideration: The six complications families

What are complications? How are they classified? What are the best examples in each class? Here is how we propose to classify them.

As a further experiment, we are publishing this article without any photographs. Let us know if this works for you, or you prefer to pepper the texts with photographs just for visual interest.

For your consideration: The six complications families

Some preliminaries. What is a complication. We take the traditional view that a complication is an additional function on a watch beyond the most basic three hand configuration. Why not distill this further so that the central sweep seconds or the subsidiary seconds hand is also considered as a complication? Well, this is because the information to display the seconds hand is taken directly from the fourth wheel in a classical wheel train of a watch. Thus, a complication uses this basic wheel train to drive additional mechanisms to derive further information to display. Like what? Here is our list of the six complications families, in roughly the order of complexity.

We attempted a list of 7 complications back in 2022, see this link for that article. But thought we will do another one with more depth into each complication. Here it goes:

1. Date complications

The date complication is the simplest to derive from the base going train of a watch. The hour wheel, which is the second (or canon) wheel drives a series of gear reductions (24 complete turns of the hour wheel makes one click on the date wheel) to drive the date. The date wheel makes one complete revolution in 31 discrete steps to represent each day for a month. The day of week is also derived the same way, but 7 steps for the day wheel to complete one revolution.

From here we can see that the grand date, or what A. Lange & Söhne calles their Outsized Date is not another complication, but a more complicated version due to the additional mechanism needed to make that happen. We name the Lange’s Outsized Date as an example because it was the first to be commercially available in 1994 with the Lange 1, Arkade and Saxonia Date watches. Though the technique was patented by sister company Jaeger-LeCoultre before.

2. Calendar complications

A step beyond the day and date is the calendar complications. From here we derive additional information from the movement of the date such that the mechanism is programmed to be able to skip displaying 31 in the short months of Feb/Apr/Jun/Sept/Nov, and go from 30 to 1. This is the basic annual calendar.

A further complication is to add the ability to program the mechanism for February to go from 28 to 1 on non-leap years (instead of going to 29 then 30), and to go from 28 to 29 then to 1 on leap years (also skipping 30). This is the basis for the perpetual calendar.

A curious complication is the week of the year in a calendar. This is a very useful complication in the German speaking countries. The A. Lange & Sohne 1815 Kalendarwoche is one such example. Another is the Glashütte Original Senator Calendar Week.

3. Astronomical indications

Astronomical indications are next. And the most common is perhaps the moon phase. This is not directly driven from the date wheel, but a special wheel set which is calibrated to make one complete revolution every 29.53 days. This is calibrated to the synodial orbit of the moon. Most moon phase displays are precise to 1 day in 122 years, but more accurate displays also exist. The A. Lange & Söhne 1815 Moonphase has a precision of 1 day in 1052 years, but the record is held by Andreas Strehler Sauterelle à Lune Perpétuelle who is able to achieve a precision of 1 day in 2 million years.

It is easy to see that the same mechanism can be used to drive a disc with graphically show the shape of the moon as it is seen from Earth (most of the time showing the Northern hemisphere view, though some like the IWC Big Pilot Perpetual Calendar show the view from both hemispheres), or to drive an actual calibrated hand to show the age of the moon.

The Equation of Time, showing sidereal and solar time is also an astronomical complication. This uses a special cam to trace the difference in the two times on Earth, and display it on the dial. Examples are the Breguet Marine Équation Marchante 5887 and the Vacheron Constantin Les Cabinotiers Celestia Astronomical.

Other astronomical indicators have also been proposed by watchmakers. For example, the Cabestan Saturnera which shows the phases of Saturn. Astronomical indications are also a traditional show of force by classical watchmakers. Many examples abound showing the stars in the sky, for example the Patek Phillippe Sky Moon Celestial and the Vacheron Constantin 57260, and Les Cabinotiers Bacchus. Also of interest are the Trilogy of Time by Ulysse Nardin.

4. Power Reserve

The fuel gauge, or power reserve indicator is a complication. This is a separate mechanism which is calibrated to count the number of revolutions turned by the mainspring and display it as a gauge to show how long the watch has already run, or how much autonomy is left in the barrel.

Many techniques can be applied to show the power reserve. One exquisite example is shown by the F. Berthoud FB1‘s power reserve indicator. The mechanism works by attaching a flat spring mounted indicator to a jewelled feeler riding on the truncated cone driven by the barrel. Another notable example is the Lange 1815 Ab/Auf, which adds the entire complication into the base 1815 movement and manages this without increasing the case dimensions. A more recent example by Lange is the Datograph Ab/Auf.

5. Chronographs

Next up in the lineup are the chronographs. If perpetual calendars and moon phase displays measure the months, years and decades; the chronograph measure time in small increments. Two variants are usually seen. The base chronograph, which is an additional mechanism which puts a stopwatch on your wrist. And the split seconds chronograph, which adds further mechanisms to allow two timings to be recorded by two chronograph hands.

The base chronograph is already a very complicated mechanism. The traditional method is to add the chronograph works, which is a set of levers and heart shaped cam driving additional hands coordinated by a column wheel. This system is democratised by using a less expensive and less precise cam mechanism, exemplified by the ubiquitous Valjoux 7750. Best examples for base chronographs in our opinion will feature column wheel control, and are found in the various Zenith El Primero examples, the A. Lange & Söhne Datograph, the Jaeger-LeCoultre Reverso Tribute Chronograph and the Grand Seiko Tentagraph.

The split seconds chronograph, also known as rattrapante. They almost always feature two column wheels, and these addis another level of complexity and several levels of difficulty in adjustment and tuning for it to work properly. For the split seconds chronograph in the IWC Da Vinci Perpetual Calendar Rattrapante, the Lange Double Split and the Triple Split. One outlier example is a chronograph which is not a split seconds, but feature three column wheels, which would prove to be a nightmare to tune is the De Bethune Maxichrono.

6. Chiming complications

And we come to the grand daddy of the complications. The chiming watches. These family comprise of a mechanism which reads the time from the going train and translates this to strikes of a gong. The most basic being the Hour Striker like the Chopard Strike One, to the five minute and quarter repeaters like the Habring Five Minute Repeater, to more complicated ones like the Minute Repeater exemplified by the gorgeous examples proposed by Patek Philippe and Vacheron Constantin. Variants to improve the tone and volume of the striking watches are also pursued. Some innovations of merit are the Jaeger-LeCoultre Trébuchet hammer system, the Audemars Piguet Super Sonnerie and the use of crystal gongs by Chopard in their Full Strike watches.

A further variant is the decimal repeater, first shown by Kari Voutilainen, which strikes the hours, tens of minutes and minutes after in stead of the traditional hours, quarters and minutes after. The most striking example is the A. Lange & Söhne Zeitwerk Minute Repeater, which strikes in symphony to the digital time displayed on the dial.

And even at this rarified level, the minute repeater can be topped. The Grand et Petite Sonnerie not only chimes the timing, but can do this automatically en passant by the hour (Petite Sonnerie) or by the quarter (Grand Sonnerie). The first of these to appear in a wristwatch is none other than the Dufour Grand et Petite Sonnerie. And the Sonnerie by Credor is an excellent example of the petite sonnerie.

Side discussion: Chronometry complications

This category is a bit more unusual, and not exactly a complication by the most narrow interpretation. The additional complications do not add to more informations being displayed, but to the accuracy of the timekeeping.

We can broadly sub-divide this category into three segments. These are the fusée and chain, the remontoire and the differential driven multi-balance system. As a side note, we do not consider the tourbillon as a complication, but as a variant of the escapement. Other examples in the same family as the tourbillon is the carousel, the detent escapement, the coaxial escapement and other exotic specimens like the Dominique Renaud DR01 Twelve First.

The best example of the pure pursuit of this family is showcased by the superb efforts by Ferdinand Berthoud. All their three collections, viz FB1, FB2 and FB3 are squarely aimed at chronometry. The FB1 incorporate the fusée and chain with a tourbillon, the FB2 the fusée and chain with remontoire, and the FB3 the use of a remontoire with cylindrical hairspring.

Of course, Ferdinand Berthoud is not the first wrist watch with any of these added mechanisms. The first to use a remontoire in a wristwatch is the F. P. Journe Toubillon Soverian Remontoir d’Egalitè. The first for a fusée and chain in a wristwatch is the A. Lange & Sohne Pour le Mérite Tourbillon, and perhaps the first cylindrical hairspring in a wristwatch is the  Jaeger-LeCoultre’s Duometré Spherotourbillon. The use of a differential to drive two or more balance wheels is first showcased by Philippe Dufour in his Duality.

Concluding thoughts

We have outlined our thoughts on complications on wristwatches, and categorised them into the six families. What are your thoughts? Let us know in the comments. Also what you think of a post without images…like it or hate it?