Watch Rant: Watch Movement

I am a watch enthusiast. I wasn’t. Until Manampiring (@newsplatter) rumbled about this watch, that watch and then, voila, here I am with the same rumbling. Then, all I know about watch is that there are some cheap digital watches, very expensive watches with analog face, rather expensive watches with both digital and analog face, powered by battery and an obsolete technology.

I wasn’t that wrong. Though I made some mistake. It is of course obsolete technology. In the era of computer, internet and smartphone, a separated time-telling device is redundant. Not to mention, (in some cases, well, many cases) money wasting. But I totally wrong that every watch powered by battery. I knew that there are clocks that don’t need batteries but not watches. Here I would like to explain some basic knowledge about watch.

I believe the best way to classify watch is by recognize its movement. The engine and drive train of watch. There are two main movements of watch, mechanical and quartz. Mechanical watches have spring as their power source. The spring will move a mechanism called escapement which in turn will move the hands. Quartz watches use electricity to make a quartz (some kind of mineral) beats. The beats control motor stepper to turn the hands. Or in the case of digital watches, it shows appropriate number. Since mechanical watches use spring, no battery required. Oppose to that, electricity in quartz watches require battery.

Spring in mechanical watches need to be wound to store energy. It can be manually wound with hand or automatically with pendulum (called rotor). Thus, there are manual wound watches and automatic watches. Modern mechanical watches keeps energy enough for around 40 hours. Some watches may endure longer than that. Some until 50 hours, others 80 hours even some may keep up until 7 days. However, many automatic movements also include manual wound as their features.

Meanwhile, the battery in quartz need to be replaced after it runs out its energy. Or not. Other than replacing battery, some watches provide other means to charge the battery. Some create technology to charge the battery using light, like Citizen Eco Drive technology. Other, like Seiko Kinetic, put pendulum in the watch (remember automatic mechanical movement?) which will generate power to charge the battery.

One of the fascination to the mechanical watches is the fact that the hands is sweeping not ticking. Well, actually not. Mechanical watches also tick like quartz watches only at at higher rate. Older watches may tick around at slower rate of 5 beats per second (bps), some even at 3.5bps. Modern watches tick for 6-8 beats per second. Some high beat watches have 10 bps. Ironically, some (much) pricier watches, like Audemars Piguet with their cal 2905, manage to make mechanical movements that able to tick 1bps just like the quartz watches. In quartz corner, while the common thing is to tick at 1pbs, there are also rare breeds that tick faster. Bulova Moonwatch manages to tick 10bps. Seiko manage to put mechanical mechanism upon its quartz movement to create mecha-quartz. In mecha-quartz the standard second hand tick 1 bps while its chronograph hand ‘sweeps’.

Any watch will suffer imperfection in accuracy. Mechanical watches are considered good when able to miss under 10 seconds per day. Quartz watches? Miss under 10 seconds per month. Digital quartz watches? Even less. Watch’s producers use different techniques to achieve greater accuracy. Different material, higher precision in making process. Mechanical watches also require additional lubrication over time. So, while no battery changing needed, periodic services or repairs are still required for mechanical watches.