Slim enough to be a dress watch, but with one of the most challenging complications of all: the minute repeater. The Patrimony calibre 1731 by Vacheron Constantin is now available in platinum, in addition to the 2013 pink gold version, with two dial colours that add style and sobriety. The 1731 movement is 3.9 mm thick and the case is 8.1 mm thick, and both the calibre and the watch remain the thinnest hand-wound repeater on the market.
The movement is a compact powerhouse of technology and innovation. On the dial side of the movement, there is a flying strike governor, with spinning weights that regulate the speed at which the hammers strike the gongs. This system is quieter than the more usual lever-type governors. The sound volume from the two gongs is optimized by connecting them to the platinum caseband and by carefully designing the space inside the case. This watch, like most repeater watches, is not water-resistant: there has to be a minimal aperture to get the sound out at a reasonable volume.
The calibre has 265 components, and it runs at 3 Hertz, 21,600 vph. Power reserve is about 65 hours.
The design is pure minimalism, based on a 1955 ultra-thin watch, and it is the classic dress watch, with a pebble-shaped profile, curving bezel, cambered dial and watch glass, baton hour hands and hour-markers. The small seconds subdial at 8 o’clock is a hallmark feature of this watch. The caseback has a sapphire window that extends to close to the edge of the watch, in order to reveal the hammers and gongs.
This is classical watchmaking at its finest. Only a small number – perhaps a dozen – of these watches are made every year, each by a master watchmaker who spends several months on each watch. The watchmaker uses over 1,200 tools in the process, some of which he has made himself. Particularly crucial is the process of tuning the gongs, by careful filing. Tests on sound are performed with the watch set at 4.49, so that the intervals between the two tones can be most easily discerned. At this time, the watch strikes four times on one gong for the hour, three times on both gongs for the quarters, and four times for the minutes. Each watch’s chime is recorded and archived, and then the finished piece is supplied with a magnifying glass and a sound resonator that enhances the sound and harmonies of the chimes.
The two references are 30110/000P-9999 (silver dial) and 30110/000P-B089 (slate-colour dial). Price is reportedly around $414,000, approximately 416,000 Swiss francs.