The essential components of a mechanical timepiece
The basic architecture of mechanical timekeeping as we know it has remained relatively unchanged for a little over three hundred years. Being entirely mechanical, a mechanical watch is one of the most intricate mechanisms ever been created by man. It is a timepiece that eschews every form of electronic component and uses a traditional mechanical “movement,” the mechanism of various cogs, gears and other moving parts, to keep time. The knowledge and expertise of which, has been passed down from generation after generation keeping the complex albeit traditional nature of mechanical timekeeping viable despite the advancements of science and technology.
Indeed, heritage and tradition are the driving forces that have kept mechanical timekeeping alive all these centuries. And despite the many types of the mechanical timepieces in existence today, the basic and essential components of a mechanical watch remain the same. Remove all the “superfluous” complications from any mechanical timepiece and what are left are the basics. The most important element of which is probably the power train, the energy system that keeps the movement of a mechanical watch “going” despite the lack of any external power source such as a battery.
Unlike quartz powered timepieces (or the latest Samsung or Apple Watch for that matter), the power train of a mechanical watch features a barrel, which is a cylindrical metal box closed by a cover with a ring of gear teeth around it. The barrel consists of several parts, including the barrel wall, arbor, and ratchet wheel. The most crucial component of the barrel, however, is a spiral spring called the mainspring, which is the true power source of a mechanical watch.
The mainspring is a long, coiled spring that stores potential energy derived from the act of manually “winding’ the spring by the crown (the knob-like protrusion on the side of the watch that is also used to set the time). When the mainspring is wound, it is coiled tightly inside the barrel, storing energy. The more the mainspring is wound the “fuller” its cache of energy. Wind it to its fullest potential and a modern mainspring can have a minimum of 48 hours of reserve power. As the mainspring unwinds, it releases the stored energy, which is transferred through the gear train (the system of gears that transmits the power from the mainspring) to the various other components of the watch. This leads us to…
The escapement, the mechanism that not only controls the release of energy from the barrel but also regulates the various gears of the movement. It is essentially responsible for converting the continuous energy from the mainspring into the intermittent impulses that drive the movement. The escapement consists of the escape wheel, the pallet fork, and most importantly: the balance wheel, which is another crucial component in a mechanical movement. The balance wheel regulates timekeeping accuracy by oscillating back and forth, the frequency of which determines the speed at which the watch keeps time.
As the escape wheel rotates, the pallet fork engages with one of the escape wheel’s teeth. This locks the former momentarily, storing energy in the balance wheel. This in turn starts oscillating and pulls at the pallet fork thereby releasing the escape wheel. This rotates again, which causes the pallet fork to engage with the next tooth locking the escape wheel once more.
This back-and-forth interaction between the escape wheel, pallet fork, and balance wheel happens continuously, ensuring the regulated release of energy from the mainspring. The escapement's design, including the shape and positioning of the teeth on the escape wheel and the geometry of the pallet fork, plays a crucial role in determining the accuracy and efficiency of the watch's timekeeping.
Adding a weighted rotor to the ensemble movement negates the need for the mainspring to be manually wound by the crown. Using the natural motion of the wearer's arm to continuously move the weighted rotor generates energy, which is then transferred to the mainspring effectively winding the watch automatically.
The self-winding (or automatic) movement is a natural evolution of the manually wound mechanical movement but is otherwise mechanically identical to the latter with the exception of the additional weighted rotor. And as long as the watch is worn regularly, it will self-wind, and the power reserve can typically range from 24 to 80 hours or more.
Another popular addition to the mechanical movement is the chronograph complication. Derived from the Greek words “chronos” (time) and “graph” (writing), the chronograph adds a stopwatch function alongside the standard timekeeping features and allows for the measurement and recording of elapsed time intervals.
There are two types of chronographs: modular and integrated. The former adds a stopwatch module into an existing timekeeping movement, while the latter has the stopwatch engineered directly into the movement from the ground up. But whatever the type, all chronographs feature a start/stop pusher typically located at 2 o’clock on the case to start the timing function; a reset pusher commonly at the 4 o’clock position to reset the chronograph back to zero; two or three subdials on the dial (depending on the movement design) to indicate the elapsed seconds, minutes, and hours; as well as the various chronograph hands to convey all the indications.
Mechanically, a clutch mechanism is essential for engaging and disengaging the chronograph hands with the main timekeeping movement. This allows for the start, stop, and reset of the chronograph functions while ensuring that the main timekeeping movement continues unaffected.
The cam and column wheel, on the other hand, are two different mechanisms that control the operation of the chronograph. The former is a notched wheel that pushes the levers to control the start, stop, and reset functions, while the latter is a more complex mechanism more often associated with high-end, luxury chronographs with a rotating column that performs the same functions albeit more smoothly and more efficiently.
In end there’s something honest and romantic about a mechanical timepiece (time only or chronograph, otherwise). The process of creating every single component; and the process of putting all those pieces together; indeed, literally every cog, every gear, every minute piece that has to be manufactured and finished; then put together to create a working and functioning mechanical device is something no electronic piece of equipment can, or will, ever compare to.
Many view this form of “technology” as antiquated and inefficient, and rightly so. Modern technology offers many convenient and infinitely more accurate ways of conveying the time rather than the physically inefficient manner of mechanical movements. But where is the fun in that? An Apple Watch and its Korean Samsung counterpart has a maximum shelf life of 5 years before another more “technologically advanced” model comes along.
Compare this with mechanical timekeeping, which has been around for over 300 years and you have a device that transcends every passing “fad.” Best of all, when kept correctly, the “shelf life” of a mechanical watch increases exponentially and expands to span generations. And since the components that make it up are sourced from elements found in the natural world mechanical movements are better for our planet in the long run making it the purer and natural alternative. This makes a mechanical watch something truly special and the physical, tactile, and emotional connection it imparts to the user makes the mechanical timepiece greater than the sum of its parts.