Vacheron Constantin Les Cabinotiers Cosmica Duo – Grand Complication

A double-sided watch with 24 astronomical complications and a flip-top case for maximum wear comfort.

Among the series of new products that Vacheron Constantin presented this fall as part of the celebration of the brand’s 270th anniversary, the Cosmica Duo – Grand Complication model stands out. This is a two-way clock with 24 complex functions from the category of astronomical complications.

The bouquet of declared functions includes a minute repeater and a tourbillon. The new calibre 2756-B1 manages this complex orchestra. The mechanism, which took 4 years to develop, is a derivative of the caliber 2756, introduced in 2020. The base of the mechanism that controls the minute repeater and tourbillon remained almost unchanged, while the two added modules were practically created from scratch. One of them controls the perpetual calendar and the starry sky map, the second maintains 6 astronomical indications.

The watch face is a complex structure of 22 parts with an optimal arrangement of all components. Its upper part is occupied by a sapphire crystal-covered map of the sky in the Northern Hemisphere. The card thickness does not exceed 0.25 mm. It rotates and reproduces the movement of the constellations in accordance with the time of the sidereal day, which can be tracked on the periphery. A white ellipse on the map indicates the area that the watch owner can observe by looking at the sky.

The lower part of the dial is reserved for two pointers of the perpetual calendar. The counter at 8 o’clock shows the current month and the 8-year cycle of leap years. The indicator at the 7 o’clock mark displays the date and days of the week.

In addition to the basic time display, the watch shows the time of the second time zone, for which the model has an additional central orange hand. The indications of home and local time are complemented by the day/night indicators located at the “4” and “8 o’clock” marks. In the window at the 6 o’clock mark, the name of the city is displayed, which corresponds to the time zone selected from the 24 options.

The reverse side of the watch, in contrast with the full-length obverse, opens up a view of the mechanism. There is also a set of cent hands, and an additional minute hand with a sun-shaped tip shows the equation of time, i.e. the difference between real solar and average civil time. In different periods, this difference ranges from -16 minutes 23 seconds to +14 minutes 22 seconds. It is caused by the elliptical trajectory of the Earth’s motion around the Sun and the tilt of the Earth’s axis at an angle of 24 degrees.

The information presented on the reverse is complemented by sunrise/sunset time indicators and day and night longitude indicators located at 3 and 9 o’clock. At the “6 o’clock” mark, there is a pointer indicating the age and phases of the moon. The masters of Vacheron Constantin designed the “moonlight” in such a way that it will be necessary to adjust its readings no more than once every 1000 years.

In addition to the functional complexity of this watch, there is another feature. The 47 x 20.20 mm white gold case is equipped with a system of movable lugs and a removable strap, which is equally conveniently attached to the watch on both sides. The case itself is inverted, i.e. the watch is comfortable to wear on either side due to the ergonomic strap attachment system.

The system of buttons and correctors on the case has also been made as convenient as possible. For example, a button built into the crown is used to adjust the second time zone, and a special selector on the case ring locks the sky map for the time being. The trigger of the minute repeater is built into the case in such a way that it is convenient to use it regardless of which side the watch is worn on.

To free up as much space as possible on the dial, the tourbillon carriage aperture was also moved to the back of the case. The carriage has the iconic shape of the Maltese Cross for Vacheron Constantin. The balance here operates at a frequency of 18,000 pcs/hour, and the design itself is complicated by a retrograde power reserve indication.

The watch is made in a single copy.