Routinely described as 20th century horology’s most important upheaval, the Co-Axial escapement was the brainchild of Englishman George Daniels. It was in 1974 that Daniels took the traditional Swiss Lever escapement, a mechanism that had been through only relatively subtle improvements throughout its entire 250-year history, and revolutionized it for a modern era of watchmaking.

In the process, he ushered in a new standard for reliability and accuracy, creating performance levels in mass-produced mechanical watches that were previously unheard of.

Below, we will set out exactly what the Co-Axial escapement is, how it works, and why it was such a giant leap forward.

Co-Axial Escapement

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What is an Escapement?

Originally invented in 1750 by another Englishman, Thomas Mudge, the lever escapement is really the heart of the watch movement. Comprising a balance wheel, hairspring, pallet fork and escape wheel, it is the system of components that regulates the discharge of energy from the mainspring, stopping it from all releasing in one go.

The impulse from the mainspring moves the escape wheel in measured increments and as it turns, it locks and unlocks the teeth of the pallet fork. The opposite end of the fork hits a balance pin which forces the balance wheel to oscillate backwards and forwards. Each time the wheel returns to its central position, it moves the pallet fork again, locking the escape wheel in place. This regulated back and forth motion is what causes the familiar ‘tick tock’ sound of a mechanical caliber.

The Co-Axial Escapement

The basics of the Swiss Lever escapement have received periodic upgrades since it was developed all those years ago. However, modernizations more commonly took the form of better materials used rather than any radical revision of the mechanism itself.

It wouldn’t be until the mid-1970s that Daniels’s innovation transformed the method entirely. Using a system of three pallets, the Co-Axial changed the traditional escapement’s sliding movement, as the fork’s teeth lock and unlock, into radial movement. In doing so, it did away with the need to lubricate the pallets, leading to not only improved accuracy but also a longer interval between services.

Co-Axial Escapement

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How Does it Work?

The Co-Axial is a more complicated setup than the Swiss Lever escapement. In the most basic terms, the biggest difference is the way its pallet fork advances the escape wheel. In the standard two-lever escapement, the impulses from the mainspring are transferred with a sliding motion, creating a large contact area between the wheel’s teeth and surface of the pallet.

That movement causes both considerable resistance and a significant loss of energy.

The Co-Axial escapement uses a third lever to free the locked pallet levers, which engages with a second escape wheel. (That additional escape wheel is mounted on the same axle as the main escapement cog, giving us the name Co-Axial).

As opposed to the traditional system, the Co-Axial transmits its energy using lateral impulses; a pushing motion that, coupled with the smaller contact surfaces, greatly increases efficiency and practically eliminates any friction.

It is for that reason that Omega’s Co-Axial escapements theoretically need no lubricating oil, although in reality, a tiny amount is used on the pallet stones to minimize corrosion.

Co-Axial Escapement

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Living With the Co-Axial

There’s no doubt the Co-Axial escapement is a massive evolution on an aged system. But what is it like in the real world?

Like any new technology, the earliest examples had their teething problems.

The very first working specimen was handmade by Daniels himself and retrofitted to the Caliber 1045 in his personal watch, an Omega Speedmaster Mk 4.5.

He took that piece, and a second prototype fitted to a slimmer model, around the most prominent Swiss manufactures for several years in the late 1970s.

Unfortunately, the industry at the time was experiencing its biggest predicament yet, in the shape of the quartz crisis. Many thought the electronics flooding in from Japan and America were set to wipe out the traditional arm of horology all together. As a result, no one was willing to invest in Daniels’ brainchild.

That changed in the 90s, when the public’s love affair with mechanical watchmaking renewed. The head of Swatch Group, Nicholas Hayek, was the first to recognize the implications of the Co-Axial, and snapped up the patent.

The original production release arrived in 1999, inside an Omega De Ville. A Co-Axial escapement was fitted to the watch’s ETA 2892, forming the Omega Caliber 2500A in the process.

While it was an immediate hit, one problem surfaced fairly soon into its run. Any substantial knock had the potential to cause the escapement’s pallet fork to move, bringing the entire mechanism to a halt. Once that drawback had been identified, Omega brought out the Caliber 2500B, with a stronger pallet bridge to afford the fork better protection.

Today, Co-Axial movements are found in the vast majority of Omega’s output, bar some of the Speedmaster models.

They have been found to be extremely reliable, and the newest generation have been fitted with the Nivachoc Shock Protection Absorber system that prevents the balance wheel from moving sideways under impact.

However, there is no denying it is a more complex apparatus than a classic lever escapement, and in the world of watch calibers, keeping things simple is usually key. The more components at play, the more chances for things to break down.

So getting your Co-Axial watch serviced is not as straightforward as with a regular piece. While certainly popular, they are nowhere near as prevalent as traditional movements, meaning there is no guarantee your local watch service center has the necessary training and skills to work on them.

As a rule, they should only be taken to authorized Omega service partners to ensure they get the care and attention they require.

Co-Axial Escapement

Photo credit: @brucebruce64

Continuous Innovation

Although securing the Co-Axial patent was a major coup for Omega, they have been sure not to get complacent. They have continued to invent, keeping their groundbreaking movements well ahead of the crowd.

In 2014, they launched a new wave of calibers made with specialized non-ferrous metals to make them completely anti-magnetic. Starting with the 8508, based on the flagship 8500, these ‘Master Co-Axial Chronometers’ are able to withstand magnetic fields greater than a 15,000 Gauss.

And in a fantastically confusing piece of labeling, the following year they introduced the ‘Co-Axial Master Chronometer’ rating, starting in the Globemaster—also paramagnetic but having passed the grueling trials for accuracy laid down by METAS, the Federal Institute of Metrology. Their certification can only be done on movements that have already passed the standard COSC tests, and to be awarded they must keep to within 0 and +5 seconds a day.

The Co-Axial escapement has been a crucial innovation in modern watchmaking and has elevated Omega’s position in the industry. They may not have quite the global appeal in the marketplace as Rolex, but with their embracing of revolutionary technology and their constant striving to improve, they are just about the only brand causing the crown to look over their shoulder.