Omega‘s history as the official timekeeper of the Olympic Games dates back to 1932, when it debuted its timekeeping services at the Los Angeles Games, using 30 rattrapante chronograph pocket watches for various sporting events. To commemorate this milestone, the brand unveiled the magnificent Olympic 1932 Chrono Chime in 2022. Having recently covered the subject of minute repeaters and taken a second look at many of these watches, I’ve realise just how thoughtless I was about what was accomplished in the Chrono Chime. It not only integrates a chiming mechanism with a chronograph, which is extraordinary in itself, but it is also imposingly sophisticated in all areas.

To recap, the Chrono Chime is a high frequency 5Hz rattrapante chronograph that is equipped with a repeating mechanism that can chime elapsed time in minutes up to 15, tens of seconds and seconds, once the chronograph is stopped. It comes in two versions, both in Sedna gold – the Olympic 1932 version and a Speedmaster version. The Olympic 1932 Chrono Chime has a white Grand Feu enamel dial with engine-turned sub-dials and is designed like a pocket watch, with the crown located at 12 o’clock and a quick conversion system that can swap cords for straps. The Speedmaster version comes with a Sedna gold bracelet and a blue aventurine glass dial, created by mixing aventurine glass powder with a binder then applying it onto the dial plate, and firing it in a kiln akin to the Grand Feu enameling technique. Neither of the watches are limited editions but both are numbered and only a handful are produced a year (In Singapore, only one has been delivered).

Both watches are massive – 45mm by 16.9mm for the Olympic 1932 and 45mm by 17.37mm for the Speedmaster – due to the nature of the movement. The Master Chronometer Calibre 1932 has three plates in total excluding bridge plates, and on the central axis, there’s a directly driven vertical clutch, a tens of seconds and seconds snail, a split wheel along with an isolator, explaining its thickness.

The movement is both remarkably accomplished and complete. It was the result of six years of development in partnership with its sister company Blancpain. At present, it is the only chronograph that can chime elapsed time down to the second. If the split function was activated, the watch will chime the longer elapsed time. It chimes a low note for the minutes, a double high-low note for the tens of seconds, and a high note for the seconds.

Going train and chronograph

Traditionally, in a watch with a chronograph and minute repeater that operates independently, the repeating mechanism is mounted on the bottom plate (dial side of the movement) with both the going train and strike train located on the bridge side and the chronograph works mounted over the barrel bridge.

However, in the Omega Chrono Chime, both complications are integrated. The going train of the watch and the repeating gear train are located on the bottom plate. The chronograph mechanism is fitted to the underside of this plate while the striking mechanism is mounted on a separate plate that is screwed to the base plate over the chronograph works. Finally, the split-seconds mechanism is mounted on a smaller plate over the strike works.

The going train is quite unusual. The second wheel, usually called the center wheel is not planted in the center of the movement but is off-centered. The third wheel drives both an indirect running seconds pinion on the left and the pinion of the fourth wheel in the middle. The fourth wheel drives the chronograph seconds wheel directly when coupled. In other words, the fourth wheel and chronograph seconds wheel are integrated in the vertical clutch assembly in center. This configuration is most optimal as it keeps both the vertical clutch and chronograph seconds wheel within the power flow of the gear train, resulting in negligible amplitude loss when the chronograph is activated. In addition, there is no additional meshing of teeth when the chronograph starts as both wheels are already on the same arbor. This eliminates the dreaded seconds hand stutter. When the chronograph is switched on, a pair of arms releases the clutch, dropping the chronograph wheel onto the running seconds wheel. Both wheels are driven together by friction, causing them to turn in tandem. This is layout is favoured by Omega and it has been employed in other vertical clutch movements such as the automatic caliber 9900/ 9300. As the second wheel is off-center, the third wheel pinion meshes with a drive wheel on which the cannon pinion is mounted.

The movement has a large mainspring barrel, offering a power reserve of 60 hours. It drives a 5Hz co-axial escapement, which is much higher than its recommended 3.5Hz frequency. This involves not just altering the train ratio and the size of the balance wheel but also the escapement. Its teeth count remains the same and thus there is still an intermediate wheel between the fourth wheel and the escape wheel, but both the escapement and the intermediate wheel were dimensioned to maximise its operation at a higher frequency. A higher frequency in a chronograph not only ensures greater rate stability but also provides a visible improvement in elapsed time measurement, down to 1/10th of a second. As with all Omega movements, the balance is free-sprung and attached to a Si14 silicon hairspring.

Repeating mechanism and strike train

A standard minute repeating mechanism consists of snails – cam-like components with steps that correspond to the number of hours, quarters and minutes. They dictate the travel of their respective racks and thereby the number of chimes to be struck. The snails are driven by the cannon pinion, which is why the repeating mechanism is often located beneath the dial.

But in order to chime elapsed time, the snails are attached to the chronograph mechanism in the Chrono Chime instead of the cannon pinion. The minute snail has 15 steps to encode 0 to 14 and is attached to the minute recorder wheel. The tens of seconds snail has 6 steps corresponding to 0 to 5 seconds while the seconds snail has six curved arms each with 10 steps to encode 0 to 9 seconds. Both seconds snails are pivotably fitted to the main chronograph seconds wheel, and as such, the watch will chime the longer elapsed time if the split was activated.

Notably, as you can see from the bridge-side image of the movement, the chronograph has an instantaneous jumping minutes mechanism. It consists of a lever with a hook on one side to ratchet the minute recording wheel and a feeler on the other to act with a drive snail cam that is fitted to the shaft of the chronograph seconds wheel. The only difference is that while the minute drive snail cam in a typical jumping minutes mechanism has a smooth contour, the snail here is stepped, much like the tens-of-seconds snail, with six steps.

Now it is worth noting that the chiming mechanism does not need a surprise piece. Traditionally in a minute repeater, a surprise piece is used to address continuous movement. It extends the zero step of the constantly rotating minute snail at the 15th minute to prevent the minute feeler from falling onto the other steps when no minutes should be struck. The surprise piece and quarter snail are joined thus when the surprise springs into action, it also moves the quarter snail forward to extend the surface area for the quarter feeler. But as the tens-of-seconds and seconds snails are attached to the chronograph main wheel, they are stopped completely before chiming can be activated and they are read by feelers.

However, the precision required to transition to zero seconds – for instance at 1:59 to 2:00 – is high. In a second, the watch has to go from striking 20 times to just 2. Slight misalignments caused by minor shocks, play, wear, and machining or assembly precision can cause the wrong step to be picked up. The six steps on the minute drive snail hence serves to enhance precision. Both the tens-of-seconds and the seconds snails are rigidly fixed to the minute drive snail cam and the entire assembly is pivotably fitted to the chronograph seconds wheel. Every 10 seconds, the steps enable the minute drive snail cam to move forward instantaneously via the jumping minutes lever sliding down its slope. As such, both the tens of seconds and seconds wheel, being attached to it, advances cleanly every 10 seconds. The same goes for the minute recording wheel every 60 seconds.

While the minute, tens-of-seconds and seconds snail are driven when the chronograph is activated, the racks, as with a classic minute repeater, are driven back to their rest position by the repeater barrel and gear train when the chiming function is activated. A magnetic governor is used to regulate the speed of the gear train and hence the chimes. The magnetic governor was invented by its sister company Breguet and first made its debut in the Breguet Classique La Musicale 7800 in 2013. Its main advantage over a classic friction-based centrifugal fly is that it is completely silent.

This design features conductive arms that rotate perpendicularly to a magnetic flux created by static magnets positioned around the outer edge of its housing. As these metal arms spin, they generate eddy currents. These currents, in turn, generate their own magnetic fields that oppose the motion of the arms. The faster the arms rotate, the greater the resistance due to the increased eddy currents, which slows the rotation. Conversely, when the rotation speed decreases, the resistance diminishes, allowing the arms to speed up. This dynamic balance ensures constant rotation, as any changes in speed are met with an opposing force that stabilizes the rotation.

The minute rack and tens-of-minutes driving pinion are fitted onto the arbour of an intermediate winding wheel that winds the barrel. The minute rack is fixed while tens-of-minutes is pivotably mounted. The minute rack, like the hour rack in a minute repeater, is circular with teeth only on a section of its circumference. As the minute snail is far from the pusher, a system of levers is used to traverse the distance and sample the minute snail and transmit this information to the minute rack.

The tens-of-seconds and seconds racks pivot on the same axis. Notably, there’s a system used to reduce the silent interval, also known as dead time, between the completion of the minutes and the start of the tens-of-seconds. Normally, dead time occurs in a minute repeater due to how each rack is driven; the number of driving/ gathering teeth does not correspond accurately to the number of strikes and thus does not account for every possible position that the racks can be in. A handful of companies have presented solutions to this, and while they ultimately achieve the same outcome – ensuring the correct number of driving teeth – they differ in intriguing ways.

In the Calibre 1932, there is an additional gathering pinion rigidly fixed to the tens-of-seconds driving pinion. It has 6 teeth to account for precisely the 6 positions (0 to 5) that the tens racks can be in. Once the minutes are struck, a hook spring which acts with a post on the minute rack picks up one of the teeth of the gathering pinion, driving the tens-of-seconds pinion below, which in turn meshes with the internal teeth of the tens rack. This gathering pinion is visible through a cutout on a circular bridge at the back of the watch.

The watch has two safety mechanisms. One of them prevents the striking mechanism from being released while the chronograph mechanism is running. It consists of a safety lever that is controlled by the column wheel. It has a pin on one end that protrudes from an oblong opening of the winding lever, shifting it in two positions to block and unblock the winding lever from being depressed. Another safety lever is used to block the chronograph operating lever when chiming is taking place. It has a post on one end to prevent the operating lever from pivoting when the chronograph pusher is depressed. The other end acts with a small cam fixed to the repeater winding pinion. The operating lever is only released when the safety lever slips into a notch of the cam.

Split seconds

On the top plate of the movement is the split seconds mechanism that is controlled by its own column wheel. Notably, it incorporates an isolator system, which eliminates friction caused by the drive lever of the split wheel dragging over its heart cam. When the chronograph is activated, the arms of the clamp lever remain open and the split wheel is free. The drive lever which is fixed to the rim of the split wheel and held under tension by a spring rests on the lowest point of the split seconds heart cam. The heart cam is rigidly fixed to the chronograph arbour, thus the drive lever causes both wheels to rotate together. When the split is activated, the pair of arms clamp down on the split wheel, immobilizing it. The heart cam continues to rotate but due to the spring tension, the drive lever maintains contact, thereby causing friction.

An isolator is an additional wheel, which is visible on the back of the watch. It sits above the split wheel and has a post on it that pushes the drive lever away from the heart cam completely when the split is activated. At the same time, the drive lever is also fitted with a ruby roller. Both solutions are used to reduce friction and, in most cases, are usually employed one without the other.

While a watch that can chime three units of elapsed time is undoubtedly a tremendous feat, Omega’s completist approach to every aspect of the movement – from the high-frequency train to the directly driven vertical clutch and instantaneous jumping minutes that doubles as a safety device, the solution to reduce dead time in the repeating mechanism to the silent governor in the strike train, and the friction-reducing solutions in the split seconds mechanism – is deeply impressive and a peerless example of both the perfection and integration of two very complex complication.

Tech Specs： Omega Olympic 1932 Chrono Chime and Speedmaster Chrono Chime

Movement: Hand-wound Co-Axial Master Chronometer Calibre 1932; Power reserve of 60 hours; 5Hz or 36,000 vph
Functions: Hours, minutes, seconds, chronograph repeater
Case: 18k Sedna gold; 45mm x 16.9mm for the Olympic 1932 and 45mm x 17.37mm for the Speedmaster
Dial: White Grand Feu enamel (Olympic 1932); Blue aventurine (Speedmaster)
Strap: Leather strap along with cord (Olympic 1932); 18K Sedna gold bracelet (Speedmaster)
Price: CHF 420,000 (Olympic 1932) and CHF 450,000 (Speedmaster) excluding taxes