You normally want ramps to have a relatively low slope: it’s hardly going to cut back on the amount of work you need to do to get something to the top if it’s too steep.
Unfortunately, it sometimes isn’t possible to construct a shallow ramp, usually due to terrain. You’ve still got to be able to get up to the top, though, which is where funiculars come into the picture.
A funicular is essentially a pair of linked carts on rails going up and down a slope. Think elevator, but tilted to the side, and using each other as counterweights instead of having their own counterweights.
Funiculars take shockingly little power to operate, since you’re really only hauling up the weight of the load. In fact, some low-tech funiculars operate by filling water tanks at the top cart and draining them at the bottom, which pulls down the top cart and vice versa. They’re an extremely effective way to get around, and since they’re usually in the mountains, you usually get a great view as well, except when you go through a tunnel. You also get quite a few in mines.
Depending on the amount of space available, the carts might have separate tracks, or they may share tracks. When they share track, there’s generally a split rail in the middle of the run that diverts the carts around each other.
Unfortunately, a funicular was the site of the worst ramp-related disaster in history. (Yes, definitely worse than the countless groin injuries caused by ramps in sports.) The Kaprun disaster occurred on a large funicular leading up to a ski resort. One of the large trams used in the funicular caught fire while going up the tunnel. The resulting smoke billowed up through the tunnel, killing more than 150 people, largely through smoke inhalation.
The disaster turned out to be caused mostly by poor training and a fault in the tram car, but public confidence in funiculars remained shaken for some years. (Maggie wouldn’t let me ride the last one we saw, but I think I’ve finally got her convinced that they’re safe.)
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.
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.
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.
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).
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.
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.