Author Archives: McCoy

Of a Certain Age

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Or: Smelt This.

ape2-300x168We’ve heard of the Stone Age, the Bronze Age, and the Iron Age. And yet, we aren't commonly taught why those ages occurred in that order. Which is just too bad, since it's pretty darn interesting.

The Stone Age has a simple explanation. Stone is easier to work than metal, and more common. We figured out how to use it first.

Ancient humans actually did master use of some metal during this time period— namely meteoric iron, a natural alloy of nickel and iron present in iron meteorites. We sometimes heated it but more often shaped it, by cold hammering, into tools and arrowheads; the stuff was quite difficult to work.

The ancient Inuit inhabitants of Greenland, though, used iron much more extensively than other Stone Age people. Greenland has the world's only major deposit of telluric iron, also called native iron, which is iron that occurs in its pure metal state.

Looking for the right tool to advance our evolution

Native copper, however, is found worldwide (as are native gold, silver, and platinum, all of which are of limited use for tools.) The hardest and strongest common native metal on Earth, copper proved one of the most useful.

Eventually we learned to smelt metals from ore and, around 2500 BC, learned to alloy the two together to make bronze, kicking off The Bronze Age. Tin was somewhat rare outside the British Isles, parts of China, and South Africa, so it actually ended up commanding prices higher than gold in many regions. We frequently used zinc, more common than tin, to produce brass.

Iron smelting first occurred circa 1800 BC but didn't become common until 1200 BC. Eventually, of course, iron became the metal of choice for civilization—it's just much stronger than most of the other options.

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Quotable

Oh, Yard Ramp Guy, and I quote:

“Stone Age. Bronze Age. Iron Age. We define entire epics of humanity by the technology they use.”

— Reed Hastings

Improving Traffic Flow

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Or: It’s Zippier with a Zipper.

All traffic isn't created equal.

For example, you've likely noticed that the morning rush hour often has greater traffic coming into the city from the suburbs and that the evening rush hour traffic clogs up the outbound lanes.

So, we tend to have traffic moving much more slowly in one direction than the other.

Accidents and our tendency to rubberneck them also cause the traffic to bunch in one direction. (Yes, we can keep listing these reasons for a while.) Unfortunately, building new lanes for our roadways can be prohibitively expensive, and it often isn't even possible, especially where bridges are concerned.

There is a fascinating solution, though:

Road zippers are heavy vehicles that have the ability to move concrete lane dividers across a lane, widening the road for one direction of traffic, narrowing it for the other. This requires a special type of moveable barrier, with shorter segments linked together by flexible steel connectors.

The road zipper, plus new barriers, are far, far cheaper than an entirely new lane. They actually pick up the segment lines using a little conveyor system, essentially acting on the same principles as a screw or a ramp (though Jeff Mann, The Yard Ramp Guy, might think I'm stretching that definition a bit).

Road zippers can move the lane at up to a top speed of 10 mph, depending on traffic, and is much safer than trying to manage traffic with cones and lights. They're especially useful on bridges. Crews on the Golden Gate Bridge have been employing a road zipper since 2010 to manage rush hour traffic, to great effect.

Any road crew that's worked on a bridge isn't going to have particularly fond memories of dealing with bridge traffic, and the road zipper provides an effective solution. We can also use this method to speed up bridge re-decking projects, moving the barrier to protect the work zone.

Transportation authorities utilize road zippers all around the world, and they're especially popular in the United States and Australia. Many cities use them on a permanent basis, while others lease them temporarily during construction work.

Even if they weren't so useful logistically, I'd still like them: they're just plain cool.

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Quotable

Oh, Yard Ramp Guy, while I like your sports quotes (go, team), I tend to stay on topic:

“If you don’t know where you are going, any road will get you there.”

— Lewis Carroll

Inclined Toward Ramps

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Working out the Angles

A gazillion people out there refuse to learn math after a certain age. Just absolutely refuse. In my experience, many of them frequently refuse math as much as possible. I can't say I get this, but enough people do it that, well, it's definitely a thing.

This causes a lot of problems for those of us who don't mind math—especially when we need to explain a concept that relies on that math.

As an example, let's look at describing ramp angles. Specifically, why do ramps have particular angles?

First off, we’ll choose the type of ramp. Wheelchair ramps, for instance, have an allowed ratio of 1:12. This means it's allowed to increase one inch in height for every 12 inches in length, which means about 3.58 degrees.

By comparison, the steepest road in the world has a 19-degree slope, a 35% grade (using the US system for determining road slopes). We figure this using a pretty simple equation called “rise over run.” (You just divide the rise, or the increase in height, by the run, or distance, then multiply it by 100. We're failing in our effort to avoid math, though.)

Why is the angle so much lower on wheelchair ramps? Well, we need to delve into some more math—in this case, the basic principle behind ramps:

Lifting an object always takes the same amount of work, no matter what method is used. An elevator works just as hard as you do to lift something; it's just capable of lifting more. A ramp lets you spread that work out over more time. You're still working hard, just not all at once.

So, the reason wheelchair ramps have such an angle is to minimize the work necessary for someone to get into a building. Many yard and loading ramps have steeper angles because we often have more limited room to fit the ramp, and we’re willing to make our workers do a bit more to earn their pay. (I understand that Jeff Mann, “The” Yard Ramp Guy, has chosen to explore his own ramp angle related to mine in his blog this week. Bully for you, Jeff, and don’t hurt yourself.)

Take a look at how I described road grade and wheelchair ramps, and then see how I described the general principle behind ramps. One has more numbers than the other, but both contain essentially the exact same amount of math. I simply used words to describe it more heavily in the latter and provided examples in the former.

This really leads me to believe the problem isn't with math itself, but the way we learn it in schools. Using more real-world problems instead of pure math might really help make it more interesting. That, and actually providing the schools with enough support to do their jobs.

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Quotable

Top this, other Yard Ramp Guy:

“There has always been a tendency to classify children almost as a distinct species.”

— Hugh Lofting

Mysteries of the Earth

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Terra Preta as Terra Firma

For being one of the most verdant and lush places in the world, the Amazon rainforest has some of the worst soil on the planet. It's highly infertile. In fact, sand from the Sahara desert, blowing across the Atlantic Ocean, supplies many of the nutrients it needs.

When sand becomes a source of nutrition, I’d call that a mystery.

There are large patches of dark earth—known as terra preta—scattered all over the Amazon Basin that are inexplicably fertile. In fact, terra preta contains some of the richest soils on the planet.

For years, settlers were not sure where it came from. One common idea was that terra preta was the result of volcanic ashfalls originating in the Andes mountains. Eventually, though, we figured out where that soil came from: it was man-made.

The native peoples of the region had spent centuries managing the soil carefully. To make it fertile, they added a mixture of charcoal, bone, and manure to the soil.

You've heard of slash-and-burn, right? Well, the natives used slash-and-char, which involves turning the cut down plants and trees into charcoal (hence the name) instead of just burning it. The charcoal is then mixed with the bone and manure, and then buried within the soil.

The creation of terra preta isn't just an interesting type of fertilization, either. That soil stays immensely fertile for thousands of years. Charcoal is the most important ingredient: it lowers soil acidity, can absorb and then slowly release nutrients over time, and provides habitat to important soil microbes with its porous surface.

The other ingredients are important as well…though much of this remains a mystery. Scientists still do not fully understand terra preta. They are working quite persistently at it, though. I’d say that mastering the creation of terra preta would be a vital tool in regenerating damaged soils around the world.

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Quotable

Yes, the Quote-Off with that other Yard Ramp Guy. En garde:

“There are dark shadows on the earth, but its lights are stronger in the contrast.”

— Charles Dickens

Taking the Road Train

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Or Maybe Just Pull Over & Watch the Traffic

Anyone who spends a lot of time road tripping has likely seen a road train, a semi truck with more than one trailer behind it. They only receive so much use here in the United States since they are difficult and dangerous to drive. Plus, they're usually limited to just two trailers.

If you want to see the really big road trains, you need to head south. A lot farther south.

Australia is the birthplace of the road train, where they first appeared in the Flinders Range of South Australia in the mid 1800s, pulled behind traction engines, giving them a much more train-like appearance.

Today, Australia still uses more road trains than the rest of the world combined—and for good reason. Australian roads are some of the longest and most desolate in the world.

The overwhelming number of consumer cars and trucks we manufacture today are not capable of traveling between service stations in many parts of Australia on a single tank of gas. If you don't plan carefully, you WILL get stranded.

It's generally just a much better idea to fly wherever you're going. (Which most people do.) If you do decide to road-trip, though, you'll spend ages on the road without seeing anyone, followed by a massive road train almost knocking you off the road with the wind from its passage.

And it doesn’t stop there. Double road trains aren't a particularly big deal in Australia. The really impressive ones are the triples and quadruples. You'll want to just pull off the side of the road when one gets near. These are the biggest and heaviest road-legal vehicles in the world, often pushing 200 tons. (There are much, much bigger ones, like the Bagger 288, but they're certainly not road-legal.)

While dangerous, these cost-effective road trains have been vital to the development of many remote Australian regions.

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Quotable

The Quote-Off with that other Yard Ramp Guy continues:

“Humor does not diminish the pain — it makes the space around it get bigger.”

— Allen Klein