The Arnold & Son Constant Force Tourbillon 11, a Tribute to Some of the Greatest Watchmakers

In haute horlogerie, few relationships have shaped timekeeping history quite like that of John Arnold and Abraham-Louis Breguet. Bound by shared respect and a deep commitment to mechanical innovation, their friendship helped lay the groundwork for modern precision watchmaking. Arnold & Son’s latest release, the Constant Force Tourbillon 11, is a tribute to that legacy and a living embodiment of it. We enjoyed spending time with this extraordinary timepiece, and here are our impressions.

Housed in a 41.5mm case of 18-carat yellow gold, a metal historically favoured by John Arnold for his finest pocket watches, the Constant Force Tourbillon 11 exudes quiet authority. The polished case is enhanced by a gently curved middle section, a slim bezel, and a domed sapphire crystal up front, paired with a flat sapphire crystal over the back, both treated with anti-reflective coating. At 13.7mm thick, the watch strikes a thoughtful balance between technical substance and classic elegance, subtly reinforced by the fluted crown. Water resistance is a modest 30 meters, just enough for everyday resilience.

The dial stands out for its three-dimensional beauty and its layers of meaning and craftsmanship. Built on a yellow gold base, the white Grand Feu enamel surface has that rare quality of depth, and the inclined sub-dial in white opal displays the hours and minutes with exceptional clarity, its concave form catching the light in subtle, shifting ways. The aperture on the right showcases the constant force mechanism, partially exposed and secured beneath a sculpted bridge in yellow gold. The true-beat seconds are marked not by a traditional hand but by a flame-blued anchor, a visual and mechanical homage to the deadbeat seconds of marine chronometers.

Turning the watch over reveals the tourbillon in full view, rotating once per minute beneath a finely polished linear bridge that holds the carriage with a variable inertia balance, again a detail inspired by the marine chronometers John Arnold was renowned for. A T-shaped spring recalls Breguet’s innovative ‘pare-chute’ shock protection system, adding historical depth and functional relevance. The movement’s finishing is nothing short of poetic. Most evocative is the hand-engraved dedication on the barrel bridge: “To the revered memory of John Arnold and Abraham-Louis Breguet. Friends in their time, legendary watchmakers always.” It reads almost like a manifesto, a declaration that centuries-old horological ideals still have a place in today’s most refined watchmaking.

Though not much of the inner workings can be seen, the A&S5219 hand-wound calibre deserves a few words as it is thoughtful in design and perfect in execution. This movement measures 33mm in diameter and 10.48mm thick, operating at a frequency of 21,600 vibrations/hour. Its dual barrels work in tandem to ensure a 100-hour power reserve, switching from one to the other to maintain optimal torque. Between the barrels and the one-minute tourbillon, the patented constant force mechanism, visible from the dial side, evens out the energy delivered to the escapement, ensuring the steady precision that Arnold and Breguet spent their lives pursuing. It’s a modern answer to the fusée-and-chain system of old and an elegant one at that.

The Arnold & Son Constant Force Tourbillon 11 is worn on a hand-stitched alligator leather strap in a midnight blue, lined with black alligator for added comfort. It’s secured with a yellow gold pin buckle engraved with the Arnold & Son logo. The watch is a limited edition of 11; the price is CHF 129,800. For more information, visit arnoldandson.com.