Going Medieval on Our Ramps

I know I’ve kinda built up the idea about myself that I don’t care about medieval warfare, that I consider it an absurd waste of thought. And, well, generally speaking, you’d be right. I think it’s a distraction from the things that actually matter, like actual historical construction methods. I’m interested in how they put things together, not how they broke them.

That being said, some slightly interesting uses were found for ramps in war, specifically for the purposes of siegecraft.

The first use was actually pre-medieval, though it was used on occasion in medieval times. Siege ramps are huge earthen ramps built right up a castle or city wall, a cliff face, or other positions of strength. They’re about as absurd as you’d think: the builders are going to come under constant attack by the people above, resulting in a wasteful loss of life. It was really only used when the besiegers grossly outnumbered the besieged, were otherwise unable to break through the enemy defenses, and had little care for loss of life on their side. The Romans used it a few times, as did a few of the smaller empires before them, and a few of the smaller kingdoms they conquered.

The other use was in siege towers. These, at least, were constructed with a bit more safety in mind for the troops on your side: not that sending them over an enemy castle wall is, particularly, a safer idea. Siege towers, depending on the whim of the builder, were generally a bizarre hybrid of ramp, staircase, ladder, and watchtower, all built out of wood and canvas and stuck on wheels to roll right up to the castle walls, where troops could exit the tower directly onto those walls.

They also usually had sheltered positions for archers to fire from. Still absurdly dangerous, of course, but you at least had some shelter from enemy arrows, at least until you got onto the wall. They still were vulnerable to fire, which medieval people loved to use on each other.

All in all: I prefer my ramps for actual construction purposes.

Archimedes, Simon and Galileo

I gave simple machines a basic overview in my last blog. This time, I’m going to go more in-depth into the history of simple machines—specifically concerning ramps.

The ancient Greeks recognized three simple machines to start with: the lever, the screw, and the pulley. The man who came up with the idea, Archimedes, was a brilliant but crazy guy. Built crazy ancient super weapons to sink entire enemy fleets one day, then jury rigged an ancient precursor to calculus the next. He’s considered one of the greatest mathematicians of all time for a good reason. He’s the kind of dude who could have moved the world, if you gave him a long-enough lever.

The Greeks added two additional simple machines eventually, but they were still lacking the ramp somehow. (They didn’t know what they were missing out on.)

It actually wasn’t until after a millennia and a half after Archimedes that the inclined plane was finally included in the list. The fellow who did it? An eccentric but brilliant Dutchman named Simon Steven (an unfortunately boring name for a genius.) Simon Steven was another one of those nutty Renaissance-era polymaths who threw the curve for everyone else. Simon Steven was the first person to figure out the mechanical advantage of the inclined plane. He also invented a wind-powered land yacht that could outrace horses.

After Simon Steven completed the simple machine sextet, of course, the development of the science behind simple machines hardly stopped. Galileo Galilei, notably, was the first to figure out that they didn’t create energy but merely transformed it. Leonardo da Vinci also made some critical discoveries regarding calculating friction in simple machines; then he promptly left them unpublished in his notebooks. It took almost two hundred years for someone else to independently rediscover them.

Ramping Up Franz and Kinematics

Simple machines are the basis of industry. Well, sorta.

A simple machine is a device used to change the direction or power of a force applied to something in the simplest manner possible. There are six devices classically categorized as simple machines: axles and wheels, levers, pulleys, screws, wedges, and inclined planes (obviously the best).

The reason I said they’re only sorta the basis for industry, though, is that the idea of simple machines is itself an oversimplification.

First off, take a look at wedges and screws. A screw is nothing more than an inclined plane wrapped around a cylinder. When you’re turning a screw, picture it inside the material—climbing up or down the ramp—as the screw turns. Wedges are just two ramps hooked up to one another, bottom to bottom, for use in transferring force perpendicularly.

Ramps make up half of the classical simple machines. Ramps rule, but we already knew that.

Then you come to wheels and axles and pulleys. A pulley is just a wheel and axle with a rope attached. It’s still super useful, of course.

At first glance, our final classical simple machine, the lever, is pretty distinct from the others. A guy named Franz Reuleaux, however, realized that, like the wheel and pulley, the lever is just a body rotating about a hinge. Reuleaux was also the one who figured out that the screw, wedge, and inclined plane were the same. Really smart cookie.

So all in all, you’ve really got two simple machines and four variants on the original list. And that’s the first issue with describing the classical simple machines as the basis of mechanical industry.

The second issue? There are a lot more than six simple machines. You’ve got four-bar linkages and cranks, for example. Our good buddy Franz identified hundreds of simple machines using his self-invented science of Kinematics, which we still use today. Way to go, Franz. Not bad for a guy born in 1829.

Nowadays, thanks to Franz and Kinematics, we actually consider joints the basis of mechanics, but that’s a story for another day.

The Incan Terraces

The Inca are surely one of my favorite ancient cultures. Much of this is due to the unusual amount of research available on their building techniques and architecture. The pieces of their engineering I’ve been reading about lately are their terraces.

Terraces might be something of an opposite of ramps, but that just makes them more fascinating. Living among some of the steepest mountains in the world, the Incans had to improvise heavily when it came to all sorts of facets of their life. Their terraces did a lot more than provide flat areas for food production (though don’t get me wrong: that was just a little bit important); they also helped to control erosion and landslides.

In fact, much of Incan architecture was built to be earthquake resistant, and the terraces were no exception. They were so well built that, despite the Incan’s comparatively low technological level, their terraces survived from Pizarro’s conquest of their empire, totally forgotten, all the way up to the twentieth century, when they were rediscovered.

Do you think anything we build today would last that long without maintenance? Not likely. This workmanship stretched all the way through their construction, too.

The Incans by no means had a monopoly on agricultural terraces, of course. Terrace farming has arisen independently in dozens of cultures worldwide, with almost as many individual styles. It’s almost certainly the most efficient method of farming in the mountains.

The most famous are almost certainly the rice terraces of the Philippine Cordilleras: they’ve actually been declared a UNESCO heritage site. You’ve almost certainly seen images of them before. They’ve been farmed continuously for something like 2000 years, which is absolutely crazy. That’s not just architecture, it’s a way of life.