Knots to Know!
The Versatile Prusik Hitch
By Tamia Nelson
November 24, 2009
Whether you're a canoeist or a kayaker or both, you're bound to find plenty of uses for rope. At a minimum, every boat should be fitted with a bow line (call it a towline or painter if you prefer). Stern lines are a good idea, as well. And what's the easiest way to attach these essential lines? With knots, of course — preferably bowlines. Once you've fixed a couple of lines in place on your boat, one fore and the other aft, you'll be much better prepared to meet the challenges of traveling over water. You can line down through a tricky drop or track upstream against the sweep of the current. You'll also find it easier to recover your boat in the event of a capsize. But rope has many more uses. If you stow gear inside your boat — and what paddler doesn't? — you'll want to tie it down. You'll also need to lash float bags firmly in place anywhere they're not constrained by decks. If you don't, your flotation will just do what comes naturally as soon as the gunwales dip below the waterline: float free. Then your boat will be left to swim (or sink) on its own. Rope is useful off the water, too. At day's end, you'll need to make your boat fast to your car's roof rack before you head home. And if you store your boat outside, you'll want tie‑downs to keep it from blowing away the first time the wind rises above a stiff breeze.
The bottom line? Rope is valuable stuff. I learned this early, even before I started running rivers, when my mountain hikes took me off the trails and up steeper and steeper slopes. Before long, I found my life hanging — well, not by a thread, exactly, but by a rope. Of course, I didn't actually hang from the rope very often. Thankfully. But my rope was my constant companion on rock faces and frozen waterfalls, always ready to help me out in time of need. We spent a lot of time together, my rope and I, and as our acquaintance deepened, my knowledge of knots and hitches and their uses grew apace. Beginning with Lesson Number One: On a mountain, when your fingers are numb with cold and your brain is addled by exhaustion, simple is good. And one of the simplest tools in the climber's bag of tricks is the prusik hitch, named after its putative inventor, Austrian mountaineer Karl Prusik. The name lost its capital "P" somewhere along the line, however. It often loses the "hitch," too. In any case, a prusik — with or without the accompanying hitch — is little more than a loop of cord that's wrapped around a host rope (or sometimes two ropes, or even something else altogether, like a branch). Unweighted, the prusik slides more or less freely along its host. Once under tension, however, it holds fast.
I'll show you how to tie one in just a minute. First, though, here's what the prusik looks like:
In the left photo, I've tied a prusik hitch around a quarter‑inch laid nylon line. On the right, the hitch encompasses both the laid line and a length of braided polypropylene. Now let's look at one of the most important ways prusiks are used:
If you paddle on moving water, you've likely heard talk of the Z‑drag (or Z‑rig), an improvised tackle that can be deployed to free a pinned boat from a rock. Spend enough time on and around whitewater, and you'll probably see one in action. All you need to put a Z‑drag together are a long, strong, low‑stretch rope (a "static line") and a couple of the metal snap‑links known as carabiners, along with a prusik hitch or two. (See the illustration below.) Anyone who's ever had to pull a wrapped boat away from the embrace of a midstream rock will understand exactly why something like this is necessary. Moving water exerts enormous force, and few paddlers are built like Arnold Schwarzenegger. So the Z‑drag is just the "force multiplier" we ordinary mortals need. In fact, bluewater sailors will note a close resemblance between the Z‑drag and the hauling tackle known as a "Spanish burton." Both offer a (theoretical) three‑for‑one mechanical advantage. That means you can shift a 300‑pound load with little more effort than it would take to move 100 pounds unaided, though the Z‑drag suffers somewhat in comparison with its maritime counterpart, since carabiners don't make very good pulleys. Still, even a little help goes a long way in a hard chance, and supplementary pulleys are available to improve the Z‑drag's performance.
Get the idea? Good. But don't assume that this sketch makes you an instant expert. I've left a lot of important details out of my schematic drawing, besides the rock that caused the problem in the first place: the second (or "brake") prusik that's often needed, for one thing, and the weighted bag placed so as to deflect the hauling rope's potentially lethal kickback if it should part while under strain, for another. These omissions are deliberate. You can't learn the techniques of whitewater rescue by looking at a picture. You have to practice them on the water, under the guidance of someone who knows the ropes. That said, a little reading can make the learning curve less steep. I recommend the Whitewater Rescue Manual, by Charles C. Walbridge and Wayne A. Sundmacher.
OK. After that quick look at the prusik hitch in action, it's time to find out…
How to Tie One On
Material matters first: Although climbers often make prusiks with webbing, boaters are more likely to have cord in their packs. Choose your cordage to meet the demands that will be made of it. Generally speaking, you want line that's about half the diameter of the rope you'll be tying off to. Rescue and salvage operations warrant 6–7mm braided synthetic, but smaller stuff works fine in less demanding applications. I used 1/8" braided nylon cord in the following photos.
Let's get tying. Begin by joining the ends of a two‑ to three‑foot length of cord with a fisherman's knot to form a loop (see left‑hand photo below):
Then throw the end of the loop opposite the knot over the "host" — it's a beaver‑gnawn branch in the photo, but in most applications it will be a rope — and weave the knotted end through the bight. (See right‑hand photo, above.) Now repeat this two more times and pull taut. Voilà!
You can often get away with a total of just two turns around the host, but I usually use three. The more turns, the greater the friction between hitch and host, and that's a good thing. The prusik is a "sliding friction knot," after all. Without the bite that friction produces, the knot won't hold under load. If the "barrel" of the prusik — this is the sleeve formed by the loops of cord around the host — is loose, the knot will slip. The same thing is likely to happen if the host is icy or overly slick.
Have you tied a prusik of your own while you've been reading along? I hope so. There's no better way to learn ropecraft. And if you have, it's time to test your handiwork by putting your prusik through its paces. Grab the barrel and push it up and down the host (see left‑hand photo below). It should slide relatively easily. Next, load the free end, pulling along the host axis (right‑hand panel). The prusik should hold fast, and if you've done everything right, it will. Mine did.
Now that you know how to tie the prusik — but before you sign up for a river‑rescue course to learn the art of rigging a Z‑drag — let's take a quick look at some of this versatile knot's…
They're really limited only by your imagination. You can use prusiks anytime you want an adjustable suspension point. Hang a shower bag so that it can be placed at exactly the right height for everyone from the littlest kid to the tallest adult. Air‑dry your dishes in a net bag hanging from a guyline — or the haul rope on your suspended food pack. Use a prusik to fine‑tune the tension on a tarp or the peak of a poncho shelter. Hang a lantern so that it's within reach when it's needed, yet out of the way when it's not. The list goes on and on and on.
You can even store your boats in prusik slings, as James Norma did in this ingenious and inventive rig:
Convinced? I'll bet you are. And if you're like me, the next time you leave home for the put‑in you'll have a couple of ready‑made loops of cord in your pack, all set to be turned into prusiks. You can never tell when you might want to tie one on, can you?
We paddlers need to know the ropes, and the prusik hitch is well worth adding to our bag of tricks. It's quick to tie and easy to use, and someday it might just save your boat — or your life, come to that. In short, it passes the Simple and Good Test with flying colors. What's…er…knot to like about that, eh?
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