So, we’ve been asked, just what is all this about canals and locks. Do they have to lock up the canals at night to keep them from being stolen? Not quite. Canals are just big ditches. The canal we’ve been on the past week, the Canal des Ardennes, was dug using shovels and horses at the same time the North and the South were fighting over federalism and states rights,  the same issues the U.S. Supreme Court is addressing right now. Back then, remember, before highways and trucks, pretty much before railroads, before paved roads, before much in the way of roads at all, the only efficient way to move goods from where they were produced to where they were used was by boat. Rivers were handy for boats but sometimes rivers went a tad wild and boats couldn’t navigate them, and sometimes rivers just didn’t go where the business folks wanted the goods to go. The solution was to dig a ditch and to drag boats through those ditches.

As in “I’ve got a mule and her name is Sal. Fifteen miles on the Erie Canal.” How’s this for progress: fifteen miles would be a damn good day for us on the Ardennes Canal.

A problem arose when folks started digging these ditches: hills. Rivers flow where rivers flow because water flows down hill, and rivers wind and wend their way from up high to down low and eventually to the ocean. Digging a canal to go from Point A to Point B, however, could be a problem if Hill C happens to be in the middle. The solution, like so much else in the Middle Ages, came from an unexpected source.

Like spaghetti, like gunpowder, like cookies with little paper messages inside, the Chinese solved this problem with hills early on. They invented locks. Marco Polo brought the idea back from China. Leonardi da Vinci put down his paint brushes long enough to draw some canal locks, and, voila, Europe went through a public works project frenzy, with every king sending the peasants out to dig ditches and the royal engineers out to build canal locks. The locks Hoop Doet Leven squeezes through today are, in some cases, hundreds of years old but continue to work in basically the same way they did when first built.

Locks are like stairs that are placed every once in a while along the canal when the land goes up or down. Between the locks the water is level. At one side of the lock the water is at one level. At the other side of the lock, the canal is at a lower or higher level. The lock is the stairway between those two levels.

Locks have one fundamental rule: they are exceedingly cool. Go through your first lock and your reaction will be, “wow, that is exceedingly cool.” Locks have no pumps, no hydraulic systems, no computers or electricity or much at all in the way of machinery (sure, some locks have been automated, but only to do the same thing that in other locks are done by muscle power). Here’s a visualization of a lock. Picture a bathtub. Place your rubber ducky in the tub. It sits on the bottom. Turn on the water and fill the tub. The water rises. So does rubber ducky. Let it float around a while. Let the water out. The water level goes down. So does rubber ducky. Now picture a 70-foot, 65-ton 86-year-old canal barge in your bath tub. Everything else is the same.

The lock is a big bath tub with a pair of swinging doors at either end. When we approach a lock we tell it “here we are” and the swinging doors swing open. We motor in and tell the lock, “OK, here we are.” The doors we came through swing shut. If we’re going up in the lock, little windows in the uphill doors open and water rushes in, filling the lock to the uphill level. Just like the rubber ducky, as the water rises, so does the barge. When the water in the lock is at the same level as the uphill canal section, the front doors swing open and out we motor.

Going down in the lock is the opposite. In we motor with the water at the uphill level. Windows in the far doors open and let water out of the lock. Down we go and out we motor, at the level of the lower section. Go to http://www.pragmasoft.be/carnets/geo/ecluse/ecluse_simulation.html and navigate the little boat through the lock.

Everything in the lock happens slowly. After you get past your fear of them, locking is calming, one element of the zen of barging, moving slowly, almost passively through the landscape.

         This is the actual speed of descending a lock, and actual lock slime.

That’s the theory of how canals and canal locks work. France is inundated with canals. Some are actual ditches dug by hand. Some are natural rivers that have been “canalized,” meaning that every once in a while along the river a dam is built and in the middle of the dam there is a lock. Upriver from the dam, the river is all at one level (i.e., the level of the top of the dam). It is not flowing, just sitting there all at the same level. Below the dam, and the lock, the river is at a lower level, maybe 30 feet or so lower, and stays at that level until the next lock. In this way a flowing river is tamed and kept navigable. You transit from one level to the next by going through the  lock, which either lifts your boat up or lowers it down, depending on whether you are traveling up hill or down.

Most days the locks are a long way apart, a half hour or an hour or even more between locks. Where it gets interesting is when the canal has to go up, or down, a hill. A few days ago we went down a “chain” of locks from a high level down into a valley, 27 locks all within 3 kilometers, most of the locks just a few hundred feet apart. It was a long day to travel a short distance. We had dinner at 5:00 and went to bed by 7:30 that evening.

Locks come in all different shapes and sizes. Which led to the problem of a boat showing up at a lock it couldn’t fit into. To get around this problem, the French government declared in 1879 that all locks would be built to a standard size, named for the minister of public works responsible for this concept, Charles de Freycinet. As a result, we travel through Freycinet-sized locks: 39 meters long by 5.2 meters wide by 2.2 meters deep. The cargo barges we encounter, called peniches, have to suck in their bellies to fit these locks. To carry the maximum cargo, these Freycinet barges are all 38.5 meters long by 5.05 meters wide. Steering a peniche into a lock is like standing three feet back from a wine bottle and trying to toss the cork back in. Hoop Doet Leven isn’t nearly that large, just 21.4 meters long and 3.8 meters wide. Watching a peniche enter a lock is an exercise in calm and panic. We’re panicked. The husband and wife who operate peniches are calm. He’s at the bow, cell phone pressed to an ear by his shoulder, cigarette in his mouth, casually tossing the mooring line onto the bollards in the lock side, all without looking up. She’s at the wheel, driving into the lock at full speed, her cell phone held to her ear with her shoulder (are they speaking to each other, probably not), and, to complicate matters, a baby will be on her hip. They never touch the sides.

An empty cargo peniche fills the locks with inches to spare. We’re the small boat on the left.

We enter like a ball in a pinball machine, banging from side to side. But we’re getting better. Harvey is at the wheel, turning it frantically to line the boat up with the sides of the lock. Sandra is at the bow, ready to lasso the bollards (mushroom-shaped metal poles) at the sides of the lock. She gives Harvey the thumbs up sign to show she’s tied on and he throws the engine in reverse to stop the barge before the front lock gates. Once the boat is stopped, Harvey hops off and lifts a blue pipe, which tells the lock to do its thing, emptying or filling, depending on whether we’re heading up stream or down. We ever so slowly either rise up or sink down. When that is done, the doors in front of us open and out we go, heading for the next lock. We’ve done 130 locks so far, so we’re pretty comfortable at it now.

All thanks to some obscure Chinese scientist, whose descendant is now busily assembling iPhones and iPads for us to use on our barges.