For the first time in almost 100 years, top-tier watchmaker Vacheron Constantin has created a bespoke timepiece to sit within the dashboard of an equally illustrious motor car. The single-edition Les Cabinotiers Armillary Tourbillon is teamed with the Rolls-Royce Amethyst Droptail.

This special request from one of Vacheron Constantin’s clients, a collector of both fine watches and luxury cars, was one that the watchmaker accepted with enthusiasm. The parameters were very precise: the timepiece had to blend seamlessly into the highly bespoke interior of the coach-built motor car, one of only four Droptail commissions, while also meeting exacting standards of engineering and shock resistance. It had to be both elegant and removable, while also complementing the aesthetics of the car’s interior.

When presented with this challenge, Les Cabinotiers of Vacheron Constantin, who specialise in responding to clients’ wishes for bespoke timepieces, set about designing a suitable piece. In searching the archives, it was discovered that the last time Vacheron Constantin was commissioned to create a timepiece for a car was in 1928. So, the chance to create a bespoke horological gem, working alongside the British marque with its commitment to excellence and meticulous attention to detail, presented a great opportunity.

The technical challenge was big, with the two luxury houses collaborating to ensure a seamless integration of the timepiece into the Rolls-Royce Amethyst Droptail’s fascia panel. Working alongside the Rolls-Royce Coachbuild design team, the marque’s bespoke arm, Vacheron Constantin’s watchmakers ensured that the shapes, materials and colours of the timepiece were in perfect harmony with its setting, while maintaining Vacheron Constantin’s pursuit of excellence.

The Swiss watchmaker came up with a unique timepiece equipped with the calibre 1990, a hand-wound in-house complication movement incorporating certain technical developments derived from Reference 57260, the most complicated timepiece in the world, presented by the house in 2016.

Crucially, this specific configuration, with time-related indications on the upper part of the dial, provided all the space needed for the tourbillon, here a complex “armillary” version. Visually, this tourbillon evokes the interlocking circles and armillas (graduated metal discs) of the famous scientific instrument modelling the celestial sphere. Designed to compensate for the effects of gravity on the smooth running of the movement, the construction of this type of regulator consists of two nested carriages rotating around two different axes at a speed of 60 seconds per rotation to form a sphere in perpetual motion.

The holder, with its polished steel outer- and bevelled steel inner-frame, was designed to be removed from its housing on the dashboard to allow the watch to be rotated through 180° for setting, winding and admiring the reverse of the calibre.

In this ultimate luxury challenge, the shared cultures of Vacheron Constantin and Rolls- Royce have created an unparalleled horological one-off: the Les Cabinotiers Armillary Tourbillon.