Mechanical watches are, quite literally, the opposite of what quartz watches are - hand-crafted, delicate, easily serviceable (and could thus last much longer than electronics), generally more expensive and exclusive, making them particularly fitting items as heirloom for future generations, as well as a tasteful addition to your possessions.
I’m going to illustrate the 4 essential components of a mechanical watch movement one by one, referencing to the Nomos caliber above with additional illustrations.
Component #1: Mainspring
The single most frequent question I was asked about mechanical watches is: how are they powered? The answer lies with a component called the mainspring. The mainspring is to a mechanical watch what a battery is to a quartz watch: an energy source. The main spring is essential a spiral torsion spring of metal ribbon that stores elastic energy when coiled up. The coiling is achieved either by hand (in a manually winding watch) or by the oscillation of a rotor (in an automatic watch - to be covered in future features). Energy would be released as the mainspring unwinds and drives the rest of the movement into operation. The mainspring is housed in a small container called the barrel.
With the energy issue out of our way, we shall continue to examine what’s at the receiving end of the energy released by the mainspring. This is where the gear train (also known as the going train) comes into the picture.
A gear train is essentially a series of gear wheels that serve two crucial purposes: 1. they transmit the mainspring’s energy to the next component called balance wheel; 2. they respond to the regular oscillation of the balance wheel and rotate at a regulated manner, consuming the mainspring’s energy at an even rate, eventually turning the watch hands to reflect passage of time. Think gear train as the bridging components between the mainspring and balance wheel.
Savvy readers might already have the following questions in mind: what is the mechanism in place that regulates the release of the mainspring’s energy? What’s stopping it from uncoiling in one go and exhaust itself in a matter of, say, 10 seconds? What’s keeping a watch running for 40+ hours with only a single round of winding?
The key to the above lies with the remaining 2 components called the balance wheel and escapement, arguably the most defining parts of a mechanical watch, regulating the various actions going on in a movement, essentially allowing a watch to, well, reliably tell time.
Let me explain the balance wheel first, before we move on.
Again in very simplified terms, balance wheel is a weighted wheel that oscillates back and forth and be returned to its center position with the help of a hairspring within (yet another torsion spring structure, though not to be confused with the mainspring). Each oscillation takes exactly the same amount of time to complete. This is the timekeeping organ of the movement, making the watch tick at regular intervals and contributing to the iconic “tick-tock” sound of a mechanical watch.
Escapement works in collaboration with the balance wheel to give the latter a small “push” to make it swing completely, while just allowing the gear trains (which eventually connect to the watch hands) to “escape”, or move, by a set distance following each swing of the balance wheel. It looks something like this (in purple):
When the 4 key components come together, they become something like this:
Still got question? Watch the below video from American watchmaker Hamilton (made in 1949!) on how a mechanical watch works. There cannot be a better video explaining the subject.
So much for Lengbeau’s (nerdy) dissection of a mechanical watch for now. Stay tuned for the conclusion of the Mechanical vs Quartz series which serves as the opening pieces of Lengbeau.