Half Hitch before Bowline

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On a rigging dismantle job.

When rigging vertical sections of timber into a rigging block.

The reason we're putting the Half Hitch before the Running Bowline is that the Half Hitch dissipates the load so that it is not the Running Bowline that is taking the full dynamic load, it is the Half Hitch that takes the initial load then it passes into the Running Bowline.

True or False?

There is a good chance of the Running Bowline failing if the Half Hitch is not put into the system first.

True or False?

Why is it the Running Bowline would fail quicker without the Half Hitch when used in this application?
 
Running bowline should meet host/load at perpendicular angle; so bowline is inline with itself; not leveraged against. Preceding with a half hitch buffers loading to bowline, gives 2 points of grab (one to almost surely get it, another to make sure it is 187% certain!). But also, the Bitters of Half Hitch/ after Half; that becomes the Standing Part pull for the Running Bowline; secures half and is inline with the mainline Standing Part, not leveraged to side (on inline pull to spar).

This region becomes the Standing Part Pull into Running Bowline, so it becomes leveraged per that; but much less; and is not leveraged per the initiating pull of the Main line, the Standing Part of the Half Hitch. The Bowline is much less depended on in this configuration to.

At least that is my version of analyizing the 2 seperate chapters of ABoK and their key differances; 1 for lengthwise/ inline pull on spar and how they are different than right angles of pull on spar.
 
True, second part false. The half hitch adds security plus speads the weight out because of less bend ratio on the rope. The bowline by itself is secure in my opinion but to save my rope I always put the half hitch, even if the loads are static and I am close the swl of the rope I'll put the half hitch.
 
I prefer the opposite just because that is what I was taught many years ago and have learned to deal with the hitch falling down. I would think the marl is better but I never use it. Old habbits are hard to break.
 
Never had a problem with the the strength of a half hitch/running bowline, but I have seen the marl of a marl/running bowline strip the cover off of a double braid.

I have also had a half hitch creep up a vertical piece when the lowering point is above the tie-off.

Thus for butt-hitching heavy pieces I always use a half hitch, and I also use a half hitch for many horizontal pieces. But,(like Mark) if I am rigging a piece that I think might fall apart, then I will use one or a series of marls. I will also use a marl (with a running bowline)if I am rigging a vertical point, I want the first knot to stay in place, and the lowering point is above the first knot.
 
There's more reasons why we put the half hitch (or Marl) in the pieces being chunked off than to dissipate the load.

One of the chief reasons is that we want to minimize the distance between the rope's attachment to the cut piece and the block. Whilst TA&SOPR video series demostrated that the fall distance doesn't change it failed to demonstrate with a dynomometer at the block the difference of having a close to block half hitch. If the half hitch is only 1' away from the block then there's going to be less force on the rope than for example if the bowline is say 5' away. Imagine as the block comes off the fall distance of the further tie point will result in additional force at the block. Whilst this whole theory is debatable without evidence I can only also conclude with a parallel example that of a swing. Same weight but further the swing seat is from the fulcrum more pendulum force is exerted. Tests should be done.

Another is that we do not want the cut piece to invert, likely to happen if the bowline was tied past the centre of the piece.

Another is we want the block to come down long and not sideways spinning and carrying on.

Another is security of having two ties ... but you can have more than one half hitch along the piece.

Regarding the second question of the bowline failing ... of course there's a higher chance without the half hitch as there's more force on the knot. But that said it shouldn't fail unless you have overloaded the system and bombed off more than 10% of the ropes SWL!

So if you are rigging pieces off and your bowlines are failing by breaking the rope then cut smaller pices. However if your bowlines are slipping off then do another round turn ... I tend to go round twice that way even less force is put on the knot.

Also there should be tension on that rope as it goes over, a slack knot is asking for it.
 
Ummmmmmmm, though at first a lil'counter intuitive; if the fall distance nor the mass doesn't change i think force is same. If, there is more line to take impact by extending the preceding half further away from pulley; then there is more shock absorber(?). This distance could be used for more drop force; but i think in a tight set rig would buffer force more/ be a good way to sneak in extra buffer. Otr limit it if not wanting extra drop distance.

i think the tightness of grip might be better; a farther levraged distance from Center of Gravity with half on 'nose' of load. Also, would getter a straighter hang if this force point was further from forcepoint of Center of Gravity; by 2 spread points making a straighter line tha 2 close points. Same as, i think the running Bowline further from half gives straighter hang; but both should be above Center of Gravity.

Obvious 1st grab should be abouve Center of Gravity not to invert; but, i think on short/wide stubbies that we can get slip from CG being between Half Hitch and Running Bowline; and Running Bowline needs CG below it to fully and immediately pull closed, or can have some problems of the gravity kind!
 
Now, I have no way of verifying this as it was info told me at the TCI expo, but this source, seeemingly reliable had told me they had done breaking tests on various slings and knot variations. The results were that the half hitch actually is slightly weaker than a running bowline on its own. They tested a Clove hitch with a back up and found that that was also slightly weaker than the Running bowline for the same reason that the half hitch is weaker. The main reason for placing it is to insure against losing the knot off the end or to rig a piece liable of breaking. Also the tests found that a loopie is stronger than a whoopie which is equivalent to a cow hitch. Anyone else hear data from these tests done a few years ago by ken, rip, and crew?
 
Ekka

"If the half hitch is only 1' away from the block then there's going to be less force on the rope than for example if the bowline is say 5' away. Imagine as the block comes off the fall distance of the further tie point will result in additional force at the block"

Sounds like that makes sense but I don't think so. The force is to do with the centre of gravity of the load and distance to the pulley, that won't change no matter where you tie it.
 
[ QUOTE ]

1. The results were that the half hitch actually is slightly weaker than a running bowline on its own.

2. They tested a Clove hitch with a back up and found that that was also slightly weaker than the Running bowline for the same reason that the half hitch is weaker.

3. The main reason for placing it is to insure against losing the knot off the end

[/ QUOTE ]

Point 1 - I do not believe that information

Point 2 - I do not believe that information

Point 3 - That is only one small reason Treebing - if you look at the half hitch you can see that it is creating less tension and compression in the rope. The Running Bowline is riddled with tension and compression. The half hitch helps to dissipate the load more evenly along the rope.
 
i loosely go with these theories; but i also think a Running Bowline's teepee can be flattened out to leverage force high enough to give less remaining tensile strength (but better/tighter grip for Running Bowline in trade) than Clove or preceding Half Hitches. A Bowline itself is different; then it's SheetBend is bending the Standing Part worser than all the rest on a decent size load/mount.

Also; IMLHO, i think that the angle of pull on these things is best where the lacing's forces are in line with itself by meeting it's host/load at a right angle. 37k Flash Animation
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Nice, Spidey, and thanks.


Any thoughts on where the half hitch, or marl, should be rotated to relative to the running bowline? I've always worked it around the piece in such a way as to make the bight going through the bowline more acute (a better choke). With a half hitch, I tie it such that it is working in the same diretion as the running bowline, so that tightening the half hitch, both before cutting, and in the moment of catching, also tightens the running bowline.
 
The half hitch keeps the running bowline set. Running bowlins without load can work themselves loose prior to making the cut.

I like a half hitch before a running bowline, because I can trust it to stay the way I left it, until ready to cut the work.
 
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