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Written by: Faraz Abidi
Written on: May 20th, 2016
Tags: mechanical engineering, lifestyle
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Faraz is a Junior at USC’s Viterbi School of Engineering, in the Computer Engineering/ Computer Science Program. He is set to graduate in December 2016. After graduation, he hopes to be a software developer and/or build hardware technologies.
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Volume XVII Issue II > From Ship Navigators to Agent 007: Cultural and Engineering Significance of Mechanical Watches
Although today, they are primarily known as fashion statements, mechanical watches have a long history of being a significant piece of mechanical engineering. Their development enabled long-distance ship travel, and for hundreds of years, they were the superior method for timekeeping. With up to hundreds of moving parts, mechanical watches are one of the most elegantly design consumer goods on the market.

A Riddle

There’s a device on the mass-market, one of the most complex pieces of engineering the average person can buy. It is actually quite common. Some people own an authentic one, but most possess an imitation. It can cost anywhere from a hundred to hundreds of thousands. This device used to be a major cultural item, but times have changed. While the device is still a popular seller, there are only a few aficionados in the world today who know - or care - about the particulars. Can you guess what it is?
The mechanical watch, as opposed to the quartz watch, is a highly significant representation of mechanical engineering. Mechanical watches can be comprised of hundreds of moving parts, and many aspects of their development require major feats of skillful engineering. They also have substantial historical significance, since mechanical watches and clocks were the most effective way to tell time for hundreds of years. Watches also play a big part in our cultural mindset. Every notable luxury watch brand – from James Bond’s classic Omegas and Rolexes, to Lil Wayne’s infamous million-dollar Panerai – has built its name off of the design of their mechanical watches.

Status Symbol

While quartz watches are more popular today, the most expensive watches are mechanical watches. Top brands, such as Jaeger-LeCoultre, A. Lange & Söhne (see Figure 2), and Patek Philippe offer watches that range from one to two million dollars, but they can be much higher, with the Patek Philippe’s Graves Supercomplication auctioned off for $24 million [1] (See Figure 1). [2]
Figure 1. Graves Supercomplication Wristwatch (from Hoodinkee.com). The image on the right features an open back, displaying the watch's innards, or 'movement.' Analysts say that it is the complexity of the movement, rather than the cost of the materials, which is responsible for the watch’s price (image from Forbes.com).

Rise of the Mechanical Watch


Mechanical Watches are more than just accessories or contraptions of intellectual intrigue: they have incredible historical significance to the Western world’s economy.
In ship travel, before Global Positioning Systems, sailors had to figure out two pieces of information in order to navigate towards their destination: latitude, and longitude. Latitude is easy to determine: sailors note the position of the North Star, and can then use a tool called a sextant to convert that to a latitude measurement.
Longitude is far more complicated. During the 1700’s, sailors lacked an effective way to determine longitude. They instead relied on a technique called ‘dead reckoning,’ which was travelling straight from a known longitude measurement, and hoping that the ship would stay the course. If there was low visibility or the ship drifted off-course, this would fail. Predictably, this form of navigation – essentially guesswork – sometimes resulted in accidents. One particularly catastrophic accident was the Scilly Naval Disaster of 1707. The navigators for a Royal British Navy fleet misjudged their location, and the ships ran aground into the Isles of Scilly. Four sank and approximately 1500 men lost their lives [3].
This disaster spurred the British Crown to create the Longitude Prize in 1714, a 20,000 Euro prize (the modern-day equivalent to $2.89 million) to anyone who could determine an accurate method for determining longitude. Scientists reasoned that if one could keep accurate time from the location that they arrived, they could compare this to the time at their current location to deduce their longitude. The watches of 1707 were nowhere near accurate enough to be used for this, so a Yorkshire watchmaker named James Harrison resolved to make one. After spending 31 years of his life on this problem, he created H4, a pocket watch that had error of less than one second per day [4].
Harrison created one of the first watches that was accurate enough to be useful. Watchmakers advanced on his designs; further developments over time resulted in higher accuracy – and cost-efficiency. Eventually, they became a widespread consumer good. For centuries, mechanical watches and clocks were the most effective, reliable, and ubiquitous method for telling time.

The Quartz Crisis

This all changed with the emergence of quartz watches during the Quartz Crisis. Prior to this event, the most accurate timekeepers in the world were highly optimized mechanical watches. Refined and modified by watchmakers over centuries, mechanical watches were incredibly sophisticated and consisted of hundreds of moving parts that worked together to tell time. In the 1970’s, they started facing competition from watches that featured quartz movements. A quartz movement is essentially a circuit that controls a seconds hand by sending a current through a quartz mineral (See Figure 3). These watches were also very simple - they could consist of less than five parts - and significantly more accurate than the best mechanical watches [5].
It was reasonable that the quartz watch would overtake the mechanical watch. Even a Casio from a garage sale can tell time thirty times better than a $30,000 Patek Philippe Calatrava. Quartz blew mechanical watches out of the water; for accurate timekeeping, mechanical watches became obsolete. Mechanical watches are abacuses to the quartz’s computers, Walkmen to their iPods. Mechanical watches became redundant, and the market began to reflect that.

Engineering of the Mechanical Watch

Mechanical watches were able to withstand the tests of time mostly due to the mechanism for telling time - the movement - which was far more interesting and appealing to certain consumers than that of quartz. In fact, watch aficionados often debate the nuances and benefits of various movements. Within the watch community, the knowledge of ‘how it works’ is considered nearly as important as actually owning the watch.
Watch fans argue that in its simple effectiveness, the internals of a mechanical watch are truly beautiful and elegant. While quartz resulted in a more accurate timekeeper, one can still do things the old-fashioned way via a system of gears, springs, and hundreds of handcrafted moving parts. A modern watch-owner can determine time in the same way that most of the world did a few centuries ago and understand it quite easily.
On a certain level, the ‘know-how’ of most watches has not changed much since the original invention. Even though the past few centuries have brought many developments for mechanical watches, the general mechanism has essentially remained the same: all mechanical watches have four major components (see Figure 4).

Mainspring

The watch’s source of power is the mainspring. It is a tightly-coiled spring that is either wound by hand, or wound by the kinetic energy of the user’s motion. Mainsprings are very small – about 20 centimeters long – yet can keep a watch ticking for weeks. The mainspring provides energy through the act of uncoiling, exerting a spring force that drives the watch.

Wheel Train

The mainspring pushes the wheel train, the system of gears that controls the watch’s seconds, minutes, and hours hands. Some watches even feature additional ‘complications,’​ such as gears that control figures indicating the orbit of the planets. Each gear is a different size, which allows them to rotate at different rates and control the different hands. The mainspring and wheel train would not work by themselves, because, like all tensed springs, the mainspring tries to release its energy all at once, rather than gradually.

Escapement​

This is where the escapement comes in. Without the escapement, the seconds hand would rapidly fly around the watch for several revolutions, and then suddenly stop. The escapement prevents this and makes the wheel train rotate at a regulated tempo by acting as a sort of stopper. When the last gear in the wheel train turns, it bumps the escapement. This bump shifts the escapement, so that its legs lock the wheel train into place and prevent it from rotating further. It holds this for a beat, then releases the wheel train to rotate again. This cycle of holding the gear then releasing it creates the apparent sweeping motion of the seconds hand.

Controller

The length of the beat for which the escapement holds the wheel train in place must be consistent in order for the watch to tell time properly. This is assured by the escapement’s own regulating system of gears: the controller. Together, the controller and escapement act like a pendulum. When the wheel train bumps the escapement, it powers this pendulum. At the top of the pendulum’s swing, the controller pushes the escapement forward, so the wheel train can move a few centimeters before bumping the escapement again. The controller’s cycle is very regular – it always completes in ‘x’ milliseconds, which should never change throughout the watch’s use cycle (when it eventually does, the watch must be serviced). If the controller allows ten ticks per second, the seconds hand will move 1/10 of the distance from its current position to the next second position every beat, which translates to ten times a second. Hence the apparent sweeping motion [6], [7].

Conclusion

Mechanical watches are a fascinating piece of engineering. From their illustrious history as a literal lifesaver of the 18th century sailor, to their importance as the only effective way to tell time, mechanical watches held great significance in the Western World. Yet, as time passed, the mechanical watch did not. They did not become significantly cheaper or more accurate after the emergence of the quartz watch, which indicated that they should have gone extinct. Instead, they were saved by fashion. Luxury brands pride themselves on the aesthetics of their movements. The informed tastemakers of the watch world decide what is of quality, based on the internals of a watch. Essentially, mechanical watches are cool now. But to relegate mechanical watches to a mere style accessory misses out on their greatest appeal: a story on your wrist.

References

    • [1] A. DeMarco. “Henry Graves Supercomplication Smashes Record, Sells For $24 Million.” Internet: http://www.forbes.co​m/sites/anthonydemar​co/2014/11/11/henry-​graves-supercomplica​tion-sells-for-24-mi​llion/, Nov. 2014 [Feb. 2015]
    • [2] M. Bernardo. “The World’s Most Expensive Watches: 8 Timepieces Over $1 Million.” Internet: http://www.watchtime​.com/blog/million-do​llar-watches/3/, Jan. 2015 [Feb. 2015]
    • [3] history.com “Scilly Naval Disaster of 1707.” Internet: http://history.org/H​istory/teaching/enew​sletter/volume13/oct​14/images/ShipsLesso​nMaterials.pdf, Oct. 2014 [Feb. 2015]
    • [4] J. Betts. (2006). John Harrison (1693–1776) and Lt. Cdr Rupert T. Gould R.N. (1890–1948). [On-line]. Available: http://www.nmm.ac.uk​/sites/default/files​/media/pdf//Gould-Ha​rrison-longitude-JBe​tts.pdf [Feb. 2015]
    • [5] GevrilGroup. “Mechanical vs. Quartz Watches: Romantic or Pragmatist?” [On-line]. Available: http://gevrilgroup.c​om/watchrepair/mecha​nical-vs-quartz-watc​hes-romantic-or-prag​matist/ [Feb. 2015]
    • [6]Torneau. “Movements.” [On-line]. Available: http://www.tourneau.​com/catalog/editoria​l_twocolumn.jsp?page​Name=mechanicalMovem​ents [Feb. 2015]
    • [7] D. Radeck. “How a mechanical watch works” Internet: https://www.youtube.​com/watch?v=uGcoIue1​Bs8, Apr. 2012, [Feb. 2015]