Arnold & Son Limited Edition Ultrathin Tourbillon Skeletons

Limited Edition Ultrathin Tourbillon Skeletons

Swiss watchmaker Arnold & Son has unveiled its latest Ultrathin Tourbillon Skeleton collection, adorned in red gold or platinum and coming in a limited edition of just 56 watches.

The A&S8320 calibre unveils its curves, apertures and details within a 41.5mm case in either red gold (5N) or platinum (PT 950), each released in a run of just 28 timepieces.

At just 3.3mm thick, it is one of the slimmest skeleton tourbillon calibres in existence and this one-minute flying tourbillon is assembled with a variable-inertia balance for enhanced calibration stability.

Radiating Originality

The purpose of a skeleton is to convey a message, be it geometric, generic or minimal. For skeletonisation of the calibre reveals pronounced curves and numerous inflection points that are highlighted by an original finish. On both editions, the bridges are treated with rose-gold PVD (4N) after being decorated with radiating Côtes de Genève stripes.

The flange around the calibre adopts this same finish, clearly revealing the Arnold & Son signature at six o’clock and enabling the off-centred white opal dial to be displayed in its purest form.

Golden Carriage

At the heart of Ultrathin Tourbillon Skeleton beats the A&S8320 calibre, whose architecture and slimness are its principal protagonists. Designed without an upper bridge to minimise its thickness, the calibre is classed as a flying tourbillon.

The variable-inertia balance with inertia blocks ensures more precise calibration over time. The slender triangular carriage is supported by a double arrow, which is actually a counterpoise. The arrowhead on the staff of the escape wheel serves as a seconds pointer, as the carriage completes one rotation per minute.

Performance Reserve

The changes to the tourbillon carriage and regulating organ give the A&S8320 calibre a power reserve of 100 hours. While this is a larger power reserve than for standard tourbillons, particularly slim ones, it is entirely in line with the performance regularly achieved by the manufacture.