In 2011, CORUM donated a one of a kind Golden Bridge automatic watch for ONLY WATCH action on behalf of research on Duchenne muscular dystrophy. This unique Golden Bridge Automatic presented with a Titalyt-treated titanium case housing the white gold baguette movement with automatic linear winding created by Corum.
The complexity of such a movement – Caliber CO313 is one of the rare movements with linear oscillating weight on the market – lies first and foremost in resolving the inertia issues inherent to any movement of this type. Hence the use of a precious and dense metal, in this instance platinum, for this linear oscillating weight weighing 4 grams and which swings 1 cm, before its motion is slowed down or “damped” by a system of gaskets that send it swinging back in the other direction, thereby supplying the movement with all the energy it needs to continue moving.
The principle governing the development of CORUM Caliber CO313 was to offer a floating, linear oscillating weight floating on rails. The latter are made in steel with a PTFE Teflon 1 coating, while the contact zones between the chariot and the rails are made from beryllium copper. This association of materials ensures optimal performance. The energy derived from the winding is transmitted via a rack fixed to the oscillating weight and constantly engaged with a reverser system – ensuring unidirectional winding – equipped with ceramic ball bearings and requiring no lubrication.
No less than four antiglare sapphire crystals are thus required to make a case that looks very much like a showcase housing a precious object. The anthracite-colored two-part dial with a red minute track echoing the ONLY WATCH signature codes conceals nothing of the fabulous mechanism and enables observers to admire the linear oscillating weight in motion. The back of the watch is engraved with the Corum logo, and with the ONLY WATCH PIECE UNIQUE 2011 inscription in red.
Model: CORUM Golden Bridge Automatic ONLY WATCH
(Reference 313.150.04/0081 FK11) – Unique Piece
CO313, Automatic baguette movement with linear winding
Oscillating weight made of Platinum
Slipping spring mechanism
Variable inertia balance adjustable by screws
Frequency: 4Hz, 28’800 vibrations/hour
Plate and bridges made of 18kt gold, guilloché decoration
Power reserve of 40 hours
Functions: Hours, minutes
Titanium case with charcoal Titalyte treatment, tonneau-shaped
37.2 x 51.8 mm
Fluted crown at 6 o’clock decorated with CORUM key
Sapphire crystal open back cover under the movement engraved with
Corum logo and ONLY WATCH 2011 PIECE UNIQUE in red
Glass: Sapphire crystal
Water-resistance: 3atm (30 meters / 99 feet)
Charcoal dial with red minuter
Applique hour indexes
Skeleton hour and minute baton hands
Black crocodile leather strap, with red hand-stitching
Buckle: Titanium tongue buckle with charcoal Titalyte treatment