Swiss luxury watch brand CORUM unveils a highly sophisticated black ceramic version of their masterpiece Golden Bridge model. In this new version, the complexity of the legendary baguette movement offers a sizzling chemistry with the case that is made with one of the toughest materials available.
Fashioning an all-ceramic watch case is a truly delicate exercise that involves injecting crystals into a mold at around 980-bar pressure. The first challenge involves ensuring that the material is uniformly spread so as to avoid any roughness in the resulting surface texture. The next step is a 30-second firing in a furnace heated to 160°C in order to harden the still porous material. This extremely tricky phase causes the ceramic to shrink by about one-third of its volume in order to reach its final 34 x 51 mm size. The daunting task calls for complete mastery of the firing time, since a few seconds too many could entail excessive shrinkage that would make the case too small to accommodate the caliber.
The ceramic Golden Bridge is a high-precision achievement instilled with an ethereally light aesthetic. The slender silhouette of the eye-catching baguette movement stretches elegantly along the length of the tonneau-shaped case. This mechanism first created in 1980 quickly stablished itself as a Swiss watch industry icon masterfully meeting the energy transmission challenge implied by its extraordinary vertical-axis construction.
The impeccably pure ceramic Golden Bridge even lines up the crown at 6 o’clock as if to form an extension of its hand-wound CO 113 movement. Its slipping-spring winding system avoids forcing the mechanism, while a specific coupling clutch has been developed to separate winding from time-setting by means of an ingenious architecture in which the wheels and pinions are mounted between the mainplate and the bridge. Rather than a classic index- or regulator-type system, the caliber is equipped with a variable-inertia balance guaranteeing excellent long-term accuracy. Beating at the frequency of 4 Hz (28,800 vibrations per hour) and endowed with a 40-hour power reserve, themovement features two pillars visible on the bridges and ensuring enhanced resistance and rigidity – and thus greater precision.
Perfectly staged within its black ceramic case framed by four sapphire crystals forming the upper glass, back and sides, the baguette movement invites observers to enjoy a 360° immersion into the magic of its linear mechanism, at the heart of a captivating play on transparency. The 5N 18K red gold upper bridge bears the hand-engraved Corum signature, surrounded by a slender scrolling motif depicting the three types of fern that grown in the forests of La Chaux-de-Fonds, the region where the Golden Bridge sprang to life. The red gold main plate is also adorned with delicate hand engravings embodying the finest watch-making traditions. Standing out against the movement, the open-worked baton-type hands appear to revel in the absence of a dial in order to accentuate the transparency of this model, while an elegant alligator leather strap fitted with a black PVD-coated pin buckle sets the ideal finishing touch.
Ref B113/01621 – 113.161.15/0001 0000R
Movement number: CO 113
Winding system: Manual
Functions: Minute and Hour
Power reserve: 40 hours
Frequency: 4 Hz, 28’800 vph
Dimension: 14 3/4”’ x 5”’
Movement finishes: Bridges and plate in 18kt gold , CORUM logo engraved on the bridge
Material: No dial
Hands: Hour and minute: Baton • 5N red gold-coated • Skeleton
Dimension: 34.00 x 51.00 mm
Thickness: 11.35 mm
Case material: Ceramic
Crown material: 5N 18kt red gold • Engraved CORUM key
Crystal: Sapphire crystal with anti-reflective treatment
Back type: Screwed in open back cover in titanium grade 5 with black PVD treatment and with glare proof sapphire crystal
Water-resistance: 30 meters / 3 ATM
Material: Crocodile leather
Interhorn/Buckle: 19/18 mm
Buckle type: Tongue buckle
Buckle material: Stainless steel
Buckle distinctive features: Engraved CORUM logo • Black PVDtreatment