Bowline on a bight vs regular Bowline tied in a bight of rope

[Howard Justice]

Both are recognized knots.

The top knot is called a "bowline with a bight" in the knot bible "The Ashley Book of Knots" (aka "ABOK"), where it is depicted as knot #1074 - ABOK #1074 in knot-nerd parlance (although Ashley's usage of this knot envisioned the bight "tail" actually being loaded, this name is generally still applied among those who use this as a mid-line knot, especially in the rope-rescue world, which is my primary affiliation).

The bottom knot is called a "bowline on a bight" in Ashley (ABOK #1080).

One key difference is that the "bowline with a bight" can be tied around a fixed object, whereas the "bowline on a bight" cannot. Another difference (as preventec47 observed) is that with the bowline with a bight, if the bight "tail" is continued with a "Yosemite finish", you create a forward-facing loop that can be loaded, which significantly increases this knot's versatility.

Both knots can be expected to have similar strengths when used as "end" knots (two-way load, loop loaded against standing part), because testing and field experience show that overloaded knots generally fail at the first tight-radius bend in the knot coming from the standing part (loaded strand), not in the loop itself.

I actually just used the bowline with a bight today to connect a winch cable as the "haul" force for 2:1, 3:1, and 4:1 mechanical advantage systems in 11mm static rope to pull an uprooted stump, and can attest to the ease with which this knot can be untied after experiencing a significant load (in my case today, on the order of 1,000 lbf). The bowline family of knots is nearly unrivaled in their ease of untying after loading, which is also why, when tied in a configuration that has a tail, bowlines should be backed up if used for human life loads or if they may experience cyclic loading and unloading.

 

[Howard Justice]

Yes. RWMille, I have used the 1074 knot w Yosemite tie off. Will use it next week w 3/4 bull rope.

 

[Howard Justice]

The pics can explain. Yesterday I watched a professional tree service take down a big oak tree of about 5 ft diameter at base. They used a winch and they tied a mid line loop on their bull rope for the winch hook to attach to. I observed him tie a regular bowline in a bight of rope instead of the regular Bowline on a bight as taught in the knot books. He said he thought tying a regular bowline was stronger and easier to untie. Take a look at the pics. The pic that has the small loop sticking out is what he tied. The small loop being the same as the tail end of a bowline tied at the end of a rope.

 

[Howard Justice]

https://blackdoor.github.io/blog/bowline-for-rope-team/
Saw this today. Reminded me of this post. Interesting that some climbers advocate this as a midline option.

 

[pdqdl]

https://blackdoor.github.io/blog/bowline-for-rope-team/
Saw this today. Reminded me of this post. Interesting that some climbers advocate this as a midline option.

There is a big difference between a rock climber in the middle of a line, and the attachment point of a winch line to pull over a tree. For starters, the forces are not as great. There are more things to worry about, as well.

For the most part, the only similarities between the two situations is that both use a midline knot. After that, pretty much everything is different.

 

[ZinTrees]

I for one can say, a bowline on a bight weaken a rope quite a bit, 1/2" stablebraid, not even an old rope, pulling a tree with the bucket truck winch and snapped it under about 2000 pounds

the rating is for a straight rope, not knots

also, be careful of snap back, this winch cable, hook, and about 60ft of rope went under my truck before I even knew what happened, it went with a bang and disappeared from infront of me, again it wasnt a hard pull either

 

[pdqdl]

You know that winch can apply far more than 2k lbs, right?

 

[ZinTrees]

You know that winch can apply far more than 2k lbs, right?

Yes, 12000 to be exact, doesn't mean you have to use all 12000
I barely had the rope tight, had just got the sag out, slow gentle pull, tree moving just fine, cable not winding onto the drum clean because it's still loose, BANG
For a rope with such a high MBS the winch should have to struggle a good bit to break it, take out half for a knot it should still be good to 3500 pounds or so no problem

 

[Howard Justice]

You guys perchance work in the Gatlinburg/Pittman Center area?

 

[ZinTrees]

You guys perchance work in the Gatlinburg/Pittman Center area?

I'm in south Knoxville, Farragut today

I've been down the Gatlinburg but not for work

 

[pdqdl]

I guess you have learned how fast the rope gets tight, eh?

I always tension a pulling rope by bouncing my hand on it as it tightens. When it starts vibrating with every bounce, it's probably as tight as you want it to get. If it starts sounding like a piano wire, you done went too far.

 

[ZinTrees]

I guess you have learned how fast the rope gets tight, eh?

I always tension a pulling rope by bouncing my hand on it as it tightens. When it starts vibrating with every bounce, it's probably as tight as you want it to get. If it starts sounding like a piano wire, you done went too far.

Same thing I do every time
edit: except when im dragging a tree, like in this case, it uprooted and got snagged, whole tree wasnt 2k pounds, 14" 25ft rotten pine, was pulling the butt while cutting it free to un snag