URWERK UR-230 'Black Star' Edges of Darkness

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The URWERK UR-230 “Black Star” arrives at the close of 2025 as a work of considerable sophistication, completing a trilogy that has explored the mechanical possibilities of URWERK’s signature satellite complication through radically different material palettes and philosophical frameworks. Where the Eagle engaged raw carbon texture and the Polaris offered mineral whiteness, the Black Star plunges into something far more conceptually ambitious: not simply darkness, but a paradoxical luminescence within shadow itself.

The Dial: Absence Rendered Tangible

The presentation of the Black Star’s dial operates according to a visual logic that fundamentally inverts conventional watchmaking’s relationship with light. Rather than seeking reflection, the dial absorbs it. URWERK‘s designers accomplished this through a composite ceramic material developed specifically for this collection, comprising laminated layers of braided ceramic, fibreglass and carbon fibre integrated within a polymer matrix. When the case is machined, this remarkable construction reveals its true character: a shiny relief emerges from the machining process, its flat surface illuminated with sparkling dots that create a dense, vibrant black-light texture. The effect proves difficult to convey in still images, as the dial’s behaviour shifts dramatically with the angle of light and the viewing position.

The complication itself remains unmistakably URWERK. Three cubic hour satellites move across a 120-degree sector within sixty minutes, their rotation orchestrated through a central carousel mechanism. The active hour, the one indicating the current time, travels along the dial face under the guidance of an openworked retrograde hand, a hand that accompanies the satellite throughout its entire journey from the zero index to sixty. Upon reaching the end of its arc, this hand executes an instantaneous flight back to zero, ready to shepherd the next satellite into its position. The minute track itself displays URWERK‘s characteristic sensibility: positioned vertically as a reference rail, it anchors the hour display to a comprehensible temporal structure.

The dial’s decoration reflects a manufacturing philosophy that extends beyond mere aesthetics into something approaching ritual. The structure itself bears finely three-dimensional engraving rendered in circular satin-brushed pattern. Subdial indications receive shotpeened, satin-brushed finishes. Hour-markers carry Super-LumiNova™ applied by hand, executed in yellow glowing blue for the cardinal points. The retrograde hand itself arrives in finely sandblasted form with anodised finishing. The satellite cam, equally sandblasted, receives a DLC (diamond-like carbon) coating that intensifies its visual depth within the composition. Additional components painted with Super-LumiNova present themselves in carefully orchestrated chromatic relationships: yellow glowing blue for automatic indication, red glowing green for the 60-minute marker and the OFF position, green for the ON indication.

The Movement: Architecture as Expression

The Calibre UR-7.30 represents the mechanical heart of this creation, developed entirely within URWERK‘s workshops and protected by what amounts to a hermetic titanium container – a mechanical safe designed to shield the complication from the everyday hazards of wear. This protection proves fundamental to the watch’s structural integrity, as the fragility inherent to the composite ceramic case necessitated additional defence for the mechanism itself.

The movement’s architecture emphasises the orchestration of surfaces and finishes as fundamental horological expression. The baseplate is machined from ARCAP P40, a copper-aluminium alloy that offers exceptional dimensional stability. The central carousel, the vital rotating hub connecting the three hour satellites, is machined from grade 5 titanium, as are the fastening screws. The hours transporter, responsible for sequencing the satellites into their correct positions, arrives in aluminium, while the 3D minutes pointer likewise employs aluminium paired with a counterweight to maintain balance as it traces its retrograde arc.

The movement’s chronometric regulation follows URWERK‘s exclusive approach through a dual turbine system of exceptional sophistication. One turbine absorbs external shocks, protecting the delicate balance spring and escapement from sudden impacts during wear. The second turbine regulates the air flow of the automatic winding mechanism itself, functioning as a true aerodynamic brake that moderates the rotor’s speed and intensity. This system represents a departure from conventional shock absorption, addressing vibration through air resistance rather than traditional jeweled bearing damping. A control positioned at the caseback permits the rotor load to be adjusted or even completely deactivated, allowing the wearer to switch between automatic and manual winding modes. Two symmetrical indicators positioned at eleven and one o’clock display the current configuration of this system.

The movement achieves a power reserve of 48 hours through a dual mainspring barrel arrangement, providing exceptional autonomy between winding intervals. The escapement employs the classical Swiss lever design, whilst the balance features variable inertia construction that permits fine-tuning of the timekeeping performance. The oscillation frequency reaches 28,800 vibrations per hour at 4 Hz, a standard frequency that balances chronometric precision against the mechanical stresses inherent to the satellite system. The balance spring itself is flat, a configuration chosen for its stability under the rotational forces generated by the moving carousel.

Within this movement, 50 jewels support the motion work and gear trains, distributed throughout the calibre to reduce friction at critical pivot points. The finishing scheme applied to these components transcends functional necessity and approaches the poetic. The carrousel receives fine sandblasting, its cage finished with shotpeen circular satin brushing and black rhodium plating that deepens the visual depth of the movement plate.

The Case: Protective Innovation and Material Courage

The UR-230 “Black Star” case dimensions reach 44.81 millimetres in width and 53.55 millimetres in length, establishing a substantial presence on the wrist. The thickness measures 14.30 millimetres, a proportion that sits comfortably between sport functionality and refined proportion. These dimensions accommodate the complexity of the satellite system and the protective infrastructure surrounding the movement whilst remaining wearable across a variety of wrist sizes.

The case material represents URWERK‘s most ambitious material exploration to date. Felix Baumgartner, the watchmaker and co-founder, described the creative challenge directly: the desire for ceramic’s aesthetic qualities, its clean, precise finish and inherent beauty, conflicted with ceramic’s fundamental fragility. A single impact risks catastrophic fracturing. Rather than accept this limitation, URWERK commissioned development of a composite ceramic specifically for this collection. This material incorporates layers of braided ceramic interspersed with fibreglass and carbon fibre, all integrated into a polymer matrix. The machining process reveals layers of contrasting materials, producing a shiny relief with sparkling dots across a vibrant black surface.

The caseback employs black DLC-treated titanium paired with transparent sapphire crystal, permitting detailed observation of the movement’s finishing whilst protecting the mechanism from moisture ingress. The transparent sapphire crystal on the dial face permits equally complete visibility of the satellite system’s operation. Water resistance reaches 30 metres (3 atmospheres of pressure), a specification suited to casual splash resistance and brief exposure to water but not suitable for swimming or submersion activities.

The strap consists of vulcanized rubber bearing the “Kiska” reference designation. The rubber arrives in brand’s specific yellow, complementing the composite ceramic case with its contrasting aesthetic continuity. Fastening occurs through Velcro, a practical solution that permits rapid adjustment whilst accommodating various wrist sizes and seasonal variations in wrist circumference.

In Conclusion: The Watch as Cosmic Meditation

The UR-230 “Black Star” concludes URWERK‘s trilogy for the 230 collection with exceptional grace. Where the Eagle presented material exploration and the Polaris offered crystalline reflection, the Black Star inverts the premise entirely. This watch does not seek to reveal light but to recontextualise it, absorbing illumination within deep shadow only to release it again in random flashes. Martin Frei’s description of the Black Star concept, drawing from astrophysics’ understanding of a collapsing star that absorbs light like a black hole yet exists at the cosmic boundary between being and disappearing, captures something essential about the watch’s character. It represents neither concealment nor pure revelation but something far more philosophically provocative: a paradoxical presence.

The craftsmanship evident throughout the UR-230 “Black Star” demonstrates URWERK‘s uncompromising approach to both technical innovation and finishing excellence. The satellite complication, refined across multiple calibre iterations, reaches new sophistication in this iteration. The dual turbine system’s approach to winding regulation stands apart from conventional automatic mechanisms. The movement’s decoration rivals manufacture standards typically reserved for precious metal sports complications. The limited edition of 35 pieces ensures exclusivity appropriate to a timepiece of this sophistication and technical accomplishment. This is a watch that operates simultaneously as mechanical theatre, material exploration, and philosophical statement about the relationship between darkness and light. The Black Star has secured its position among the year’s finest creations without question.

URWERK UR-230 “Black Star” Technical Specifications

UR-230 Black Star – CHF 150,000 (Swiss francs / excluding tax)

Movement

Calibre UR-7.30 developed by URWERK
Winding Modular automatic winding
Escapement Swiss lever escapement
Frequency 28,800 vph – 4 Hz
Balance Variable inertia
Jewels 50
Balance-spring Flat
Energy Double barrel
Power reserve 48 hours
Materials Baseplate in ARCAP P40, 3D minutes pointer in aluminium with counterweight;
Steel central spring; hours transporter in aluminium; central carrousel and screws in grade 5 titanium

Finitions

Hour-markers painted with Super-LumiNovaTM
Structure finely 3D-engraved with a circular satin-brushed pattern
Shotpeened satin-brushed subdial indications
Finely sandblasted carrousel with a shotpeened, circular satin-finished and black rhodium-plated cage
Finely sandblasted satellite cam with DLC coating
Finely sandblasted anodised 3D hand
Components hand-painted with Super-LumiNovaTM: yellow glowing blue for the hour-markers; yellow glowing blue for the automatic indication; red glowing green for the 60-minute marker and the OFF position of the automatic indicator; green for the ON indication.
Polished screws

Indications