Safe Operating Practices for Slings

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These slings are 7/8” dia. with a safe knotted working strength of 10,625 lbs.

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Chris (or Tim), what was the tensile of these slings? Or, what safety factor was used to determine the WLL when knotted? Thanks.
 
Average Breaking Strength = 85,000 pounds

Maximum Working Load (4:1) = 21,250 pounds

Knotted Working Strength = 10,625 pounds (1/2 of max. working load)
 
Jamie's comments:

The working load factor was derived from testing with the fiber supplier and the rope manufacturer. It can be used at 4:1 unless otherwise stated by OSHA or another operating body like ANSI etc.

They may pick but the coating would help that bond.

People are making a switch toUHMPE slings, Dyneema or Spectra…We chose Vectrus due to the fact it doesn’t stretch, it doesn’t melt, and has no creep to fail factor like the HMPE’s.

If you are looking to change out the Wire slings to some thing lighter and more user friendly, it would have to be a rope. The 12 strand makes a good sling however if you didn’t have to splice it, you could use a double braid.

Hope this helps. We can also put movable chafe sleeve on eyes and rope sections if asked for it…And Yes, I think Wesspur has added some large slings to its offering
 
we bought that 100 foot length of 1 inch amsteel from sherrill. has an eye at both ends right now. It's freakin' huge diameter, I'm suprized it wasn't called 1.5" by the way it looks.

(the splice is very long and fat)see picture. was very cool just to see and handle such a large diameter amsteel.

plan on cutting like two 30 footers and two 20 footers and have one spliced eye on each one.

Going to use them for crane work only, spider legs.
 

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Thanks Tim. I always thought 5-1, but the manufacturer is the place to go!

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I always thought 5 to 1 also for rigging.
Do all exotic fibers go to 4 to 1?

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Mark and Norm, I was wondering the same thing.

I wonder if the different manufacturers have their own set of design factors based on the types of exotic fibers that they specifically develop and use?

I will try to look into this more.
 
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we bought that 100 foot length of 1 inch amsteel from sherrill. has an eye at both ends right now. It's freakin' huge diameter, I'm suprized it wasn't called 1.5" by the way it looks.

(the splice is very long and fat)see picture. was very cool just to see and handle such a large diameter amsteel.

plan on cutting like two 30 footers and two 20 footers and have one spliced eye on each one.

Going to use them for crane work only, spider legs.

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Xman, that's an awesome looking eye splice. Did Sherrill splice that or did Sampson Rope do it? What's the tensile strength and WLL for 1" Amsteel spliced that way, and do you plan on having the crane pull them out from under a load if necessary?

I know that they started using Amsteel for winch lines around 6-7 years ago in logging out on the west coast, but it hasn't caught on yet around here.

How's the abrasion and picking of the fibers on Amsteel if you pull on them with a crane?
 
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Going to use them for crane work only, spider legs.

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1. What's the tensile strength and WLL for 1" Amsteel spliced that way, and do you plan on having the crane pull them out from under a load if necessary?

2. How's the abrasion and picking of the fibers on Amsteel if you pull on them with a crane?

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1. It looks like Amsteel Blue in the pic.
Amsteel Blue 1 inch average breaking strength = 109,000 lbs.
Amsteel 1 inch average breaking stength = 90,000 lbs.
AND
It looks like a Samson splice?

2. We have been using 1/2" & 5/8" Amsteel for spider legs for 4 or 5 years now. It does 'fuzz' up quickly, but the 'fuzzed' fibers protect the other fibers from abrasion.
Haven't had any issues with "picking".

If I had to do it again, I would absolutely use Amsteel again. Maybe try a 'jacketed' version, Amsteel 2, Endura Braid, Maxi-Braid or Pro-Force.
We chose to use Amsteel due to it's dielectric properties. (Working close proximity to energized lines)
 
Norm, very good points. I've always been impressed with the strength of Amsteel Blue and have wanted to have some spider legs made from them.

What exactly is the 'jacketed' version, Amsteel 2?
Will Samson Rope make special orders, or do they just deal in bulk?
 
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What exactly is the 'jacketed' version, Amsteel 2?
Will Samson Rope make special orders, or do they just deal in bulk?

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Here ya go!

http://www.samsonrope.com/index.cfm?rope=193

http://www.yalecordage.com/html/pdf/industrial_marine/low/Pg7.pdf

http://neropes.com/product.aspx?mid=0EB636408F3CF50674F49998659EDA45&lid=3&pid=102

http://allgearinc.com/AGBRS.htm

Also, Roger Barnett can get reasonable prices on 1/2" & 9/16" ropes from Puget Sound Ropes.

In regard to special orders, I would call the manufacturer. The phone #'s should be on each of the sites.
 
Chris,

I don't know if sherrill did it or Samson, I just know i bought it from sherrill. Was in their bargain basement.

To be honest, i didn't know the tensile stregnth, I just saw sherrills figure of 34,000lbs for 1/2" and figure it was greater than 64,000lbs. which was good enough for me.

109,000lbs. COOL!

I actually don't like the fibers grabbing on the amsteel, I started a post on this complaining about my 1/2" amsteel lines. I didn't like how quickly they were getting fuzzy and pulling fibers.

Now, I don't pick logs with the amsteel. I switch to very heavy duty straps for that. I imagine if I pulled amsteel from under a heavy log, it wouldn't be good.

On my other post, I asked if maybe I could take the jacket off of a stable braid bull rope and put it over the 1/2" amsteel. Nick said yes it would be good, basically Amsteel 2. something i had never heard of.

Now, cuttenwolf tells me I need to check out a post on masterblasters site, a lot of talk about amsteel. A lot of bad talk, like melting easily and stuff. I haven't checked it out yet.

Amsteel is expensive that's for sure.

I think the bargain basement discount price they were asking for this 100' with eyes was around $1400.

Oh, by the way Nick. I might be shipping two of these amsteels to you and have you splice in eyes. It looks quite simple and I'm sure if I review the video of you teaching us splicing I could do it. But I never have time.
 
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Thanks Tim. I always thought 5-1, but the manufacturer is the place to go!

[/ QUOTE ]

I always thought 5 to 1 also for rigging.
Do all exotic fibers go to 4 to 1?

[/ QUOTE ]

Mark and Norm, I was wondering the same thing.

I wonder if the different manufacturers have their own set of design factors based on the types of exotic fibers that they specifically develop and use?

I will try to look into this more.

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I spoke with Howard Wright, the Industrial Application Engineer for Samson Rope and he said the following:

"We’d suggest that you follow the TCIA BMP Crane Use manual and use a 5:1 design factor for calculating the WLL. One thing to keep in mind is that Amsteel and Tenex are made of two very different materials (dyneema and polyester) with very different physical properties. Polyester has 3 times the elongation as dyneema so remember to factor that in with regards to shock loading when you use Amsteel slings."
 
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