The Going Train - A Melodrama in Three Parts

When we last looked in, the energy in our mechanical watch or clock had entered the device by means of a purposeful winding or by taking advantage of the potential energy in a raised weight as it descended to the earth. The energy was then stored in a tightly wound mainspring (in the case of the watch), wound around an arbor and connected to a barrel, which was both free to spin and capped with gear teeth. The barrel, which comprises all of those elements - the mainspring, arbor, and the gear-capped cylinder - interlocks with the all-important going train, which is the subject of this week's adventures in horology.

The Cast of Characters:

- The Mainspring Barrel  - a strong, steady type, as we saw in last week's episode. Strives to keep things moving smoothly, but can be a bit pushy.

The mainspring barrel, with and without the mainspring. Photo from Wikimedia Commons, but lacking a source. If this is your photo, please contact me and I will credit you!

- The Center Wheel - a newcomer to the story. In lockstep with the Mainspring Barrel, it keeps a very regular schedule. The Center Wheel has the honor of holding the Minute Hand, which gets paraded around once an hour like clockwork. Also charged with driving the Third Wheel.

- The Third Wheel - an awkward but necessary character. Is only included in the train to make the math work, and he knows it. Takes his duty of driving the Fourth Wheel very seriously, however.

-  The Fourth Wheel  - The Fourth Wheel has the dubious distinction of carrying the second hand - dubious because of the diminishing number of clocks that choose to flaunt a second hand. Worries that he will soon be obsolete. Also troubling: his second function of driving the escape wheel could easily be taken over by the Third Wheel, who has upward aspirations.

He's very shy.

- The Escape Wheel  - a spiky fellow, but absolutely necessary member of the Train. Has an impeccable sense of time and knows just when to give the Balance Wheel a push to keep it in the game. Very tight with the Escapement - they have a whole system worked out to make sure things happen on time.

Courtesy of mfrasca at en.wikipedia.

- The Pinions  - Small but mighty gears, without them the math simply would not work out. They feel strong attachments to their respective main gears and ensure that communication between all the biggest players comes off without a hitch.

In a watch, the pinion is on the outside. But you get the idea - it's a smaller gear rotating with the main gear to dial up or dial down the speed of rotation.

The Plot:

The reckless and headstrong Mainspring is hell-bent on pouring all of its power into the timepiece at once. There is much consternation and frenzy - too much energy in the watch at once will destroy the lovely Hairspring and rip apart her equally entrancing sister, the Balance - and without the Balance, there can be no Time! When it appears that no solution is forthcoming, at the last minute the valiant Gear Train leaps into action.

The Action:


The spring is wound and the stage is set. The mainspring pushes inexorably on the Mainspring Barrel, which grabs hold of the Center Wheel's pinion and forces it into lockstep. The dutiful pinion transmits the force of the Mainspring Barrel to the Center Wheel.

Due to the loyal pinion, the Center Wheel does not turn with nearly the force of the Mainspring Barrel, and lets the world know of its success by spinning the minute hand around the clock face at the rate of exactly one time per hour. The Center Wheel captures the attention of the Third Wheel's pinion, which spins the Third Wheel and distributes the Mainspring Barrel's energy even further. Already things are looking up for our heroines, the Hairspring and the Balance.

The Third Wheel spins the Fourth Wheel's pinion, raising the rate of rotation in its excitement. The Fourth wheel spins frenetically around at one turn per minute. In the midst of this frantic rotation, the Fourth Wheel finds the time to drive the escape wheel - the last gear to stand between the Mainspring Barrel and the Balance.

The Escape Wheel looks odd - its teeth are spiky, and it's made of different stuff than a proper watch gear. But the Escape Wheel is a steady fellow. He knows that without him, the rest of the watch gears would rotate with abandon, expending the Mainspring Barrel's energy with no regard for Time at all. The Escape Wheel is a regulator - he rotates precisely one tooth at a time in an arrangement he's worked out with his friend the Anchor. The Anchor is precisely that - it keeps even the Escape Wheel in check. Once the Escape Wheel has been brought down to a steady tick-tock rhythm, it sends just a bit of its energy down do the Balance - just enough to keep her spinning, rather than destroying her and the Hairspring in the process.


The Denouement: 
Thanks to these brave gears, the force of the Mainspring Barrel has been dialed down to a manageable force, and is even useful in keeping the Balance - she who actually keeps the time - running. Along the way, we passed over the contributions of the Motion Work and the underlying input from Gear Ratios.

All topics for the future.

Until next time!