To develop the tourbillon, Speake-Marin enlisted the experts at La Fabrique du Temps in Geneva, who built it to his specifications. Positioned at 5 o’clock, the 60-second tourbillon’s function is to maximize timekeeping precision by averaging the effects of positional variations caused by gravity. However, to many watch aficionados, a tourbillon’s more important role is an aesthetic one, and this one should not disappoint: as it rotates, it catches the light and the eye thanks to the fine finishing of its topping-tool shaped cage, and of the heat-blued hand that indicates seconds. An isochronism-improving free-sprung balance and a lightweight, energy-efficient silicon escape wheel and anchor are also integrated into the movement, as elements to improve timekeeping precision.
The minute repeater is activated by a slider on the case band at 9 o’clock. It chimes the hours, the quarter-hours and minutes after the quarter-hours so enabling the ‘reading’ of the time without having to look at or see the dial. It features an “all-or-nothing” mechanism, found on the highest-quality minute repeaters, which avoids the incorrect time being chimed if the slide is incompletely activated. The regularity of the chimes are silently and precisely controlled by a centrifugal inertia regulator, which is visible through the sapphire exhibition caseback. Also on display are the repeater hammers and the gong with ‘London-Geneva’ engraved on the repeater mainspring bridge — again, a nod to Speake-Marin’s days as a watch restorer in London, where he first learned about repeaters, and his early days as an independent watchmaker in Switzerland) while the straight drum-like sides and form of the Piccadilly case and the open dial act as an amplifier for the crystalline chimes.
Watching the repeater elements at work is not the only reason to take a loupe to the caseback: the back side of each Renaissance movement is decorated with a different intricate hand-engraved design (the model Speake-Marin showed at Basel has a dragon motif), making each one a unique piece. Speake-Marin plans to make only six pieces total and has set a price of 270,000 Swiss francs for each.
Movement: Dimensions = 32.4mm x 5.36mm; power reserve = 100 hours; 29 jewels; 330 components; Speake-Marin signature motif topping-tool design tourbillon cage; free-sprung balance; balance frequency = 21,600 vph/3Hz; silicon anchor and escape wheel; two-hammer minute repeater featuring all-or-nothing mechanism; Speake-Marin bridge design and hand-finishes; unique, hand-engraved motif on back plate; minute repeater chime mechanism engraved with “Geneva – London”
Functions: Hours, minutes, small seconds (on tourbillon cage); minute repeater featuring an all-or-nothing mechanism and centrifugal inertia regulator; 60-second tourbillon
Dial and hands: Foundation-style, heat-blued hour and minute hands; heat-blued seconds hand on tourbillon cage at 5 o’clock; open dial revealing finely-finished movement
Case and strap: Three-piece Piccadilly case in 18k rose gold; dimensions = 44 mm x 11 mm; two-position Speake-Marin crown; minute repeater slider on case band at 9 o’clock; sapphire crystal treated with nonreflective coating; water-resistant to 30 meters; sapphire display back; “Speake-Marin – Minute Repeater – The Piccadilly – Tourbillon” engraved on circumference of caseback; natural alligator-skin strap with gold tang buckle