Author Topic: Knot suggestions for in-line pull on an I beam?  (Read 6251 times)

knot rigger

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Re: Knot suggestions for in-line pull on an I beam?
« Reply #15 on: May 08, 2015, 07:09:49 PM »
Thanks Alpineer

nice picture.  This idea seems most promising to me.  when you tried that, and snapped the pic, did you try and load it at all?  How did it behave?  I'm gonna try this on dry land today and let you know how it behaves for me.

thanks

alpineer

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Re: Knot suggestions for in-line pull on an I beam?
« Reply #16 on: May 08, 2015, 10:12:51 PM »
Thanks Alpineer

nice picture.  This idea seems most promising to me.  when you tried that, and snapped the pic, did you try and load it at all?  How did it behave?  I'm gonna try this on dry land today and let you know how it behaves for me.

thanks

It passed my hard pull hand power testing. I could get the tail to suck under the wraps somewhat, but the lashing as a unit never failed to lose it's grip on that square aluminum stock. Of course, the tighter the wraps, the better. Re-tucking the tail between itself and the bight's end and from the opposite side of the bight should stop the tail from getting sucked under the lashing, and provide further locking of the tail. It's simple, effective, and esthetic (looks a bit like a wall knot from the end), although you may find that re-tucking the tail isn't really necessary for your application. 
« Last Edit: May 31, 2015, 01:11:15 AM by alpineer »

SS369

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Re: Knot suggestions for in-line pull on an I beam?
« Reply #17 on: May 08, 2015, 10:39:56 PM »
Hi knot rigger.

To illustrate better, I hope, the idea I offered, here is a picture using what I have on a job site. Its the closest item I have to an I-beam. As I am familiar with the term I-beam it means two flanges separated by a web thus leaving a space both sides behind the rope, in this situation. In this webbed space is where you can do the frapping wraps and then tie off, perhaps bowline-like as shown with the standing part long enough to use for your needs.

Alpineer's suggestion is very much like a whipping, such as at a rope's end and may need the body of something inside of it to snug against. It may work...

The riding wraps will spread the load and chafing forces and the frapping will further tighten it. Then the tie off will centralize the load and allow it to swing in any direction.

Hopefully I've communicated this better.

SS

Dan_Lehman

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Re: Knot suggestions for in-line pull on an I beam?
« Reply #18 on: May 09, 2015, 05:09:19 AM »
Thanks Alpineer
nice picture.  This idea seems most promising to me.
Surely this cannot be --as I have an idea in the hat!   :P

Quote
Dan, you have an intersting idea of a two step solution:
tie a binding hitch to the beam,
with a leg loaded hitch tyed to the the binding hitch.
That could be the ticket to minimizing the chafe the best.
It's a little complicated,
I was really hoping for an elegant single hitch solution.
You missed the sense of my qualifying "essentially, ..." :
which was merely to signify the functional aspect of what
I intended as a more-or-less one-step solution.  E.g., one
ties an anchor hitch around nothing and turns the
long tail around the object 'a la Alpineer's wrapping,
but taking the tail through the waiting-for-it hitch, and
maybe tightening at the end a little back'n'forth between
hitch's gripping and holding of binding lines and those
lines themselves to effect the tight binding to the object.
(One could try "slipping" the hitch-around-nothing so
to then run with a bight (= 2 strands vs. 1) to wrap
the object; this also requires one to have a good sizing
of material needed ... .)

(One might wonder if some working of the rockclimber's
old around-the-waist, bowline on a coil could effect much
the same!?  --I'm thinking that it would not tighten so well.)


--dl*
====

knot rigger

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Re: Knot suggestions for in-line pull on an I beam?
« Reply #19 on: May 10, 2015, 07:35:06 PM »
Hi guys, thanks for all the great suggestions.  Hopefully I can make some time to "dry" test the ideas soon.

Quote
E.g., one
ties an anchor hitch around nothing and turns the
long tail around the object

Dan, you're right, I didn't fully understand your suggestion, thanks for clarifying, it's quite elegant.

Quote
I could get the tail to suck under the wraps somewhat, but the lashing as a unit never failed to lose it's grip on that square aluminum stock. Of course, the tighter the wraps, the better.
 

Aplineer, Your solutions is almost exactly the same as a common whipping, where you'd want the tail to get sucked under.  But that won't happen with a hard surface so much.  The trick with both methods I think will be getting the wrapping turns tight enough.  I do have the benefit that the rope will shrink in length (and grow in diameter) as is gets water logged over time.

SS, you're suggestions is great as well, and solves best the need for frapping turns to take tension on the lashing.  It wasn't completely clear from my description, but the tail of the knot needs to come off the bottom flat face of the I beam.  I took a 2nd look at the beam and raft last night to be sure.  If the knot tail comes off the side of the I beam, at the gap between top and bottom flanges, the tail would chafe on the bottom flange as it went to the raft.

thanks agian for the suggestions, I'll keep you informed as how it all works out.

alpineer

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Re: Knot suggestions for in-line pull on an I beam?
« Reply #20 on: May 31, 2015, 01:17:31 AM »
Hi guys, thanks for all the great suggestions.  Hopefully I can make some time to "dry" test the ideas soon.

Quote
E.g., one
ties an anchor hitch around nothing and turns the
long tail around the object

Dan, you're right, I didn't fully understand your suggestion, thanks for clarifying, it's quite elegant.

Quote
I could get the tail to suck under the wraps somewhat, but the lashing as a unit never failed to lose it's grip on that square aluminum stock. Of course, the tighter the wraps, the better.
 

Aplineer, Your solutions is almost exactly the same as a common whipping, where you'd want the tail to get sucked under.  But that won't happen with a hard surface so much.  The trick with both methods I think will be getting the wrapping turns tight enough.  I do have the benefit that the rope will shrink in length (and grow in diameter) as is gets water logged over time.

SS, you're suggestions is great as well, and solves best the need for frapping turns to take tension on the lashing.  It wasn't completely clear from my description, but the tail of the knot needs to come off the bottom flat face of the I beam.  I took a 2nd look at the beam and raft last night to be sure.  If the knot tail comes off the side of the I beam, at the gap between top and bottom flanges, the tail would chafe on the bottom flange as it went to the raft.

thanks agian for the suggestions, I'll keep you informed as how it all works out.

We're still waiting. ;)