Opus XIII has only one thing in common with any other watch and that is its balance and escapement; the rest of the mechanism is pure invention, the brainchild of independent watchmaker Ludovic Ballouard. 

The display is produced by two separate power sources working as a team. One mainspring barrel drives the escapement through the going train and keeps the balance swinging at a steady 21’600 vibrations an hour. The other barrel provides the energy for the display of minutes, triggered every 60 seconds by the center wheel of the going train. 

The key element is an outer minutes ring driven by the second barrel. Every minute, it jumps forward a step, released then locked by a rocking lever with two pallet stones, controlled by a cam working off the center wheel. A peg on the advancing ring flips each minutes hand forty degrees in turn, revealing them in succession around the dial. At the end of the 59th minute, a second outer ring comes into play, its crenelated rim simultaneously rotating the fifty-nine minutes hands back into their hiding places. 

The mechanism for the hours is no less ingenious. Here again it relies on an outer ring that jumps forward every sixty minutes, turning the triangle of the old hour 180° so that it disappears beneath the faceted dome on the dial, and simultaneously turning up the next hour. At the heart of this mechanism is a snail cam that rotates once an hour. A lever drops off the edge of the cam, pulling a rack to turn a pinion that advances the hours ring. At the 12th hour, instead of turning up a triangular hour hand, the hours ring rotates a wheel attached to a connecting rod that pulls open a sliding shutter to reveal the Harry Winston logo in the center of the faceted dome. 

Both mainspring barrels are wound by turning the crown back and forth. A rocking pinion engages the barrel for the going train when the crown is turned in one direction and shifts over to engage the other barrel when the crown is turned in the opposite direction. Similarly, when setting the time, the crown is pulled out and turned one way to advance the minutes and the other to advance the hours. 

Opus XIII, which reinvents time, once again illustrates the creative explosion triggered between the Harry Winston team of designers and watchmakers and its partners in the Opus Series. Harry Winston believes nothing in watchmaking is beyond human ingenuity, and Opus XIII invariably proves it right.