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The Hennessy knot comes up a lot. Looks confusing at first but it's really a pretty simple process that's repeated a few times.
I was thinking about why it exists. In all my knot books I've never come across it.
My guess is that it provides a knot that is reliable, yet can be easily untied after being put under heavy load. Otherwise why wouldn't we just tie a couple of half hitches.
What do you all think?
The load is pretty much carried by the first couple of wraps - the rest just holds it all in place. It isn't a knot. That's why it has such appeal to those of us with eight thumbs.
Tom Hennessy is very clear in explaining that it is a lashing, not a knot. A knot distributes the force of the load differently than a lashig. A knot can seize up under load. The lashing does not. There are some knots that undo easily once loaded (eg Trucker's hitch") but many knots tighten up under load to the extent they can not be untied. The lashing has none of these problems. I prefer the ring buckle system in part because it avoids having to snake the ends of the suspension rope through the loops in the tree huggers. But the HH lashing is a very effective suspension system that uses minimal additional gear and has been tested to be the lightest of any of the options available for the HH hammocks. Not a bad solution depending on your priorities.
It's in all of your knot books--you're just looking for something different. Look up the cleat hitch (e.g. http://www.animatedknots.com/cleat/index.php ) and you'll see the Hennessy lashing right there.
The only difference is that you're using standing parts of the support rope as the horns of the cleat. The hitch--or lashing in our case--is the same.
I never had much trouble with the Hennessy lashing... I've been trying to figure out how to explain it differently, since so many people have issues with it.
Here's an idea. I'll assume that you're right-hand dominant; just switch the hands if you're a lefty.
Make a fist with your left hand, and then extend your thumb and pinky fingers. Take the end of your support rope and grasp it with your middle three fingers--doesn't matter which way it's going.
Now start wrapping the rope in a figure 8 around your thumb and pinky. Once you've wrapped it a few times, pause. Here comes the thought exercise.
Imagine that your pinky is the support rope that points toward the hammock. So all those wraps around your pinky are really wrapped around the support rope, before it reaches the tree huggers.
The first tree hugger loop is where your middle three fingers are. Your thumb is the little bit of support rope that runs in between the tree hugger loops. So every wrap that's on your thumb is going around that rope between the tree huggers.
(the second tree hugger loop is not represented unless you have polydactyly, in which case your thumb and second index finger do tree hugger duty.)
On a related note, the coil that a lot of us use on our tarp guylines, which runs very easily without tangling, is really just a cleat hitch/Hennessy lashing in which the cleat horns have been removed. Fun with knots!
Hope this helps!
A picture is worth a thousand words, a video...? I never had much trouble with the lashing either, once I found the link below.
http://www.theplacewithnoname.com/hi...lter/hknot.htm
FB
A cleat hitch...doh! I've used that hitch on my boats hundreds of times, but with the horn cleat absent I didn't recognize it.
So, bottom line is the Hennesy knot, aka cleat hitch, provides a reliable and easy to untie attachment at the lowest weight possible. The price you pay is that it's not very adjustable.
I like adjustability, so for the moment I use the stock Hennessy line with the Hitchcraft RopeTies. http://www.hitchcraft.net/
The Hennessy knot - hitch, lashing, whatever - falls under the general category of "outside" fasteners - which includes all knots, hitches, and lashings that do their work of increasing friction without having the bitter end clamped in the knot. They all work like the Hennessey - which is also called a 'lineman's hitch' - by taking several turns around the standing line to take the strain instead relying on jambing the bitter end where it will get badly stuck. You can replace many traditional knots with outside knots. For example, you can tie two lines together (this is a "knot" to the lexicographers amongst us) by wrapping the two ends around each other 6 or 8 times, leaving several inches of the bitter ends free and finishing by tucking loops of the bitter ends through the middle.They won't jamb there and to release you just pull one of ends. You can also replace the sheet bend with an "outside" bend. The uses of outside knots and hitches are almost endless and they work with slippery line. A little experimentation with a couple of ropes is all it takes to figure this out and you don't even have to leave the rocking chair.