ombining the architectural grandeur of gothic art with the mesmerising flow of water, this collection reveals a sculptural vista without precedent, meticulously calibrated to elicit an emotional response. The piece was born of a new challenge the brand set for itself: for the first time ever, the movement was designed and imagined specifically for a sapphire case.

The RM 75-01 Flying Tourbillon Sapphire exists in three distinct expressions. Two of these, produced in editions of 10 pieces each, combine clear and coloured sapphire crystal, while the third, crafted entirely of clear sapphire, has been issued in an edition of 15. These variations were inspired by the aquatic realm: each reference possesses a unique hue evoking a specific seascape and atmosphere.

The model in clear sapphire has a case recalling the surface of waves, while its sea-green rubber strap suggests the seabed and dreamy tropical beaches. The two other versions have coloured sapphire casebacks. One of these is a lilac pink shade reminiscent of a South Sea twilight; the other is a sapphire blue richly evoking the deep-sea realm. With an immutable crystalline structure, the sapphire case plays a functional, aesthetic and sensory role. The stone’s smooth, touchable surface exudes warmth and comfort when worn. This singular material, a result of specialised expertise, is preciousness and innovation incarnate.

Blending the crystalline transparency of the oceans with the majesty of gothic architecture, Richard Mille transcribes these influences in striking similes that guide conception of the movement, casing and decorative elements. The fully skeletonised RM75-01 calibre is conceived as an aethereal sculpture, with each component standing out through its precision and finishing, highlighting the flying tourbillon and flying barrel.

Each detail of the movement brings into focus this mechanical symphony humming with technical virtuosity and poetic elegance. Sweeping arcs, omnipresent in this creation, translate fluidity and motion. The flange itself, daring in its proportions, evokes an architectural dome. Inspired by the ribbed vaults that have witnessed millennia and sustained artistic movements, this monumental frame in microblasted red gold rests on pillars of satin-polished titanium. Playing on vivid contrasts between solid and empty space, it imbues the heart of the calibre with light when darkness falls, thanks to touches of SuperLuminova. The index markers are echoed in the lines of the barrel, reinforcing an overall sense of harmony and dramatically staging the calibre.

The RM75-01 calibre gives rise to a fascinating paradox: although minimalist in its components, it boasts exceptional precision and reveals an unexpected complexity due to its bold architecture. The titanium baseplate, practically metallic lacework, firmly holds the wheels with their involute-profile gear teeth, the tourbillon and the barrel. The absence of upper bridges to hold these elements is what makes them ‘flying’, accentuating the skeleton effect of the movement, while nonetheless ensuring resistance to any situation. This design choice banishes all excess, strengthening the visual rhythm. The bridges reveal ultra-precise craftsmanship that plays with volume and perspective, enhanced by pellucid sapphire and meticulously executed microblasted satin finishes. To contrast with the rhodium-treated wheels, the titanium baseplate in 5N gold PVD treated brings a touch of warmth to the mechanics.

The highly openworked and minimalist baseplate adopts a multilevel design, forming a triangular structure that associates dynamic energy and aesthetic balance. In the lateral openings, the minute bridge plunges through the caseband, revealing powerful curves and reflecting the pursuit of striking volumes.

The transparency of sapphire reveals the entire structure of a movement, a striking feature that is especially satisfying in the RM 75-01 Flying Tourbillon Sapphire. Richard Mille was the first to fully harness its potential for the integral machining of watch cases. The synthetic sapphire used enables the creation of all three case components: the bezel, caseband, and caseback.

Machining sapphire represents a true technical feat. Its extreme hardness, 9 on the Mohs scale, or 2,000 Vickers, just below that of diamond, makes it highly resistant to scratches but allows only micron-level tolerances to ensure the perfect fit of each component. Working from a block weighing several dozen kilos, extracting a tripartite case requires over 1,000 hours, including 40 days of grinding around the clock. A third of this time is devoted to polishing, a process made particularly complex by the curves and pillars characteristic of Richard Mille cases.

The creation of coloured sapphire through the incorporation of metallic oxides into the crystal structure marked a second stage in the exploration of this material. The process is even more complex and delicate than for creating transparent sapphire, requiring extremely precise control of temperature and growth rate. The slightest variation can result in uneven colour distribution or the formation of bubbles. Achieving an exact colour match between blocks remains a significant challenge.

The RM 75-01 Flying Tourbillon Sapphire embodies an metaphysical balance. The modernity and technical sophistication of its sculptural calibre harmonise with timeless inspiration drawn from historical architecture and the softness of the oceans – a duality that perfectly reflects Richard Mille’s artistic and technical approach, where diverse worlds converge to open new creative horizons for the brand.

TECHNICAL SPECIFICATIONS

MOVEMENT DIMENSIONS
29.71 x 20.78 x 5.45 mm

JEWELS
18

BALANCE
CuBe, 4 arms, 4 setting screws, moment of inertia 7.5 mg•cm2, angle of lift 50

FREQUENCY
3 Hz (21,600 vph)

BALANCE SPRING
elinvar par Nivarox^®

SHOCK PROTECTION
KIF Elastor KE 160 B28

BARREL SHAFT
Nickel-free Chronifer® (DIN x 46 Cr 13 + S) with the following characteristics:
• Stainless
• Antimagnetic
• Suitable for tempering

POWER RESERVE
Around 65 hours (+/-10%)

BASEPLATE AND BRIDGES IN GRADE 5 TITANIUM
These components are manufactured in grade 5 titanium, 5N gold and grey PVD treated. Grade 5 titanium is a biocompatible, highly corrosion-resistant and remarkably rigid alloy, which enables the gear train to function effortlessly. The alloy is 90% titanium, 6% aluminium and 4% vanadium. This combination further increases its mechanical properties, which explains its frequent use in the aerospace, aeronautics and automobile industries. As a consequence, the whole assembly is extremely rigid, with precise surface flatness, an essential for the perfect functioning of the gear train. The skeletonised baseplate and bridges were subjected to separate and extensive validation tests to ensure they met rigorous strength requirements.

FLYING TOURBILLON WITH VARIABLE-INERTIA BALANCE
Positioned at 6 o’clock, the flying tourbillon is a complex regulating mechanism. The distinctive feature of the so-called ‘flying’ tourbillon is that its cage is assembled without an upper bridge, creating the impression of weightlessness and offering perfect visibility.

The free-sprung balance offers better reliability in the event of shocks or movement assembly and disassembly, and also guarantees better chronometric results over an extended period of time. The regulator index is eliminated, and a more accurate and repeatable calibration is possible thanks to 4 small, adjustable screws located directly on the balance.

FAST-ROTATING FLYING BARREL (5.2 HOURS PER REVOLUTION)
The fast-rotating flying barrel used in the RM 75-01 provides the following advantages:
• The phenomenon of periodic internal mainspring adhesion is significantly diminished, thereby increasing performance. • Provision of an excellent mainspring delta curve with an ideal power reserve/performance and regularity ratio.

BARREL PAWL WITH PROGRESSIVE RECOIL
This device permits an appreciable winding gain (around 20%), especially during the start of winding. It is also helpful in ensuring even distribution of the mainspring’s internal tension.

WINDING-BARREL TEETH AND THIRD-WHEEL PINION WITH CENTRAL INVOLUTE PROFILE
The central involute profile of the winding-barrel teeth and pinion provides an optimal pressure angle of 20°. This promotes effective rotary motion and compensates for possible variations in the engagement of the going train, thus ensuring excellent torque transmission with a distinct improvement in performance.

SPLINE SCREWS IN GRADE 5 TITANIUM FOR THE BRIDGES AND CASE
This permits better control of the torque applied to screws during assembly. These screws are unaffected by physical manipulation during assembly or disassembly and age well.

MOVEMENT
• Anglage and polishing by hand
• Hand-polished locking sections
• Sapphire-blasted milled sections
• Lapped and polished contact points
• Burnished pivots

STEEL PARTS
• Sapphire-blasted surfaces
• Anglage and polishing by hand
• Burnished sections
• Satin-finished surfaces

WHEELS
• Concave chamfering with a diamond tool
• Circular-finished faces
• Rhodium plating (before cutting the teeth)
• Minimal corrections applied to the wheels in order to preserve geometry and performance

The entire case of the RM 75-01—bezel, caseband and caseback—is cut and milled from solid blocks of sapphire. No external structures are used to support the assembled parts. Sapphire is known as a particularly scratch- resistant material with a hardness of 2,000 Vickers. Made of aluminium oxide (Al2O3) crystals, it is transparent thanks to its molecular composition.

The creation of coloured sapphire crystals requires precise incorporation of metal oxides into the sapphire crystal. The colour is determined by the types and quantities of oxides present within the crystal structure. Coloured sapphire is very sensitive to the heating process and crystal growth rate: if the right temperature conditions are not respected, it can affect the way oxides diffuse into the crystal lattice and lead to the uneven distribution of colours or undesired hues. Similarly, too fast a growth rate can lead to uneven colour and the generation of bubbles within the crystal.

The machining of such components was another challenge faced by Richard Mille, one made all the more difficult as the sapphire machining process is exceptionally delicate. Although extremely tough, sapphire does not allow for even the slightest error during milling and cutting. Creating a case of this quality takes over 1,000 hours of machining, of which 430 hours are spent on preforming the case components and 350 hours on polishing the whole watch case. To ensure optimal optical properties, the front and back bezels have been treated with an anti- glare coating. The tripartite case is water resistant to 30 metres, ensured by 2 Nitrile O-ring seals. The case is assembled using 24 spline screws in grade 5 titanium and abrasion resistant washers in 316L stainless steel.

DIMENSIONS
32.90 x 46.75 x 14.35 mm

UPPER FLANGE
5N red gold with polished and microblasted steel markers. Index points filled with approved luminous material.

CRYSTAL
Bezel side
• Sapphire (1,800 Vickers) with anti-glare treatment (both sides)
• Thickness: 2.30 mm
Caseback
• Sapphire with anti-glare treatment (both sides)
• Thickness: 2.30 mm

VARIATION
• Clear sapphire (15 pieces)
• Clear sapphire upper bezel, caseband and lilac sapphire lower bezel (10 pieces)
• Clear sapphire upper bezel, caseband and blue sapphire lower bezel (10 pieces)