One of the slimmest tourbillons in the world is shedding its adornments. Pared back to its purest expression, the Ultrathin Tourbillon Gold is elegantly revealed. Its vast dial displays an almost lunar silver-toned opaline finish, while the off-centred hours dial is made of genuine white opal. Nothing now distracts the eye from the hypnotic workings of the ultra-thin flying tourbillon—the signature of the collection.
The Ultrathin Tourbillon Gold is a harmonious timepiece housed in an 8.3 mm-thick case. Its dial with a wide opening has received a remarkably refined treatment that is unprecedented in the history of this model, an Arnold & Son icon. The vast expanse of the dial features two apertures. One houses the hours dial and the other welcomes the visible elements of the A&S8300 calibre. The Ultrathin Tourbillon Gold expresses itself with elegance.
With a bassiné design, the slim 5N red gold case encircles the dial. A fine metal band of the same golden colour surrounds the hours dial and the tourbillon aperture. These repeating round lines are established according to a gentle yet rigorous geometry, creating a symmetry that enables the tourbillon carriage to stand out all the more clearly. At the heart of the Ultrathin Tourbillon Gold beats the A&S8300 calibre, which—at only 2.97 mm thick—is one of the slimmest ever designed. The highest point of the calibre is at the top of its tourbillon carriage.
The Ultrathin Tourbillon Gold showcases the A&S8300 calibre, a marvel that’s only 2.97mm thick and remains one of the thinnest tourbillon movements ever made. It’s an enhanced version of the A&S8200 calibre found in the initial Ultrathin Tourbillon. The A&S8300 features a variable inertia balance and an improved power reserve, offering up to 100 hours of power. The movement display is exquisite, featuring Côtes de Genève on the mainplate, circular satin-finished wheels, blued screws with mirror-polished heads, and hand-polished bridges.
In this iteration, the petite sub-dial is crafted from authentic white opal. Meanwhile, the primary dial features a silver-toned opaline appearance that directs the focus towards the ultra-slim flying tourbillon. The tourbillon’s structure is modeled after a sextant and anchor, with a center point that mimics the running seconds display, completing a revolution every 60 seconds.
The variable-inertia balance ensures more stable calibration over time. The redesigned tourbillon carriage echoes the leading role John Arnold played in marine exploration during the 18th century. Its triangular shape evokes a sextant, while its double-arrow counterpoise represents an anchor. The point in the middle serves as a seconds marker, as the carriage completes a full rotation in one minute.
In the background of the tourbillon, its bridge appears in the mainplate aperture, hand-engraved with a design inspired by the engravings found on John Arnold’s pocket watches. Crafted in 3N yellow gold, it blends with the gear train while creating an aesthetic contrast with the rest of the calibre. Modifications to the tourbillon carriage and regulating organ have increased the power reserve of the A&S8300 calibre, which lasts 100 hours. While this is a high power reserve compared to classic tourbillons, particularly slim ones, it is entirely in line with the performances regularly achieved by Arnold & Son calibres.