Broken sling

[pete mctree]

I run with the calculation of a 2 fid length minimum for a straight bury where a fid length is 21 times the diameter of the cordage. So when you do the math, the bury length on the large splice seems inadequate, backed up with the comparison of the second.
I still think a comparable part of the failure is down to the miss match size of block you used.
Cool thread, it's great to learn

 

[Burnham]

Indeed.

 

[stig]

I just went and remeasured the burial length of the same type sling as the one that broke.

It is 35", sorry.
Why can't we all just do it in centimeters, like civilized people!!!

I have one old folding rule in inches from when my wife and I lived in Cali 23 years ago, but it works opposite of the rulers we have here, the numbers run the other way.
I think that was what screwed me up.

Also I just figured from the colorcoding that it is not a 1" but a 7/82 sling.

Sorry, but when have I ever claimed I was smart?

 

[High Scale]

No can do.

We can't get it here and Bailey's don't sell in bulk.

So for us it is cheaper to buy ready made from Bailey's when we do our biannually order.

Stig, you got an account at Bailey's? I got a good deal on 1" Tenex from Wesspur, spliced myself a dead eye sling, not managed to break it yet.

 

[stig]

My problem is that shipping stuff across the Atlantic costs an obscene amount, unless you go big.

So I have a deal going where Richard and I get together with a few select competitors, most of them former apprentices and buy in bulk.

We do it once about every 2 years, and by ordering about 1-1½ tons of stuff, we can keep shipping costs down to 1/10 of the total amount.

Since most of what we get is logging gear, chains, bars and wedges, we shop at Bailey's.

If I order one sling from Wesspur, the shipping will most likely be more than the value of the sling.
I bite that bullet every year when I send x-mas presents to folks in california.

 

[pete mctree]

Postage is no fun to pay. Worse is import duty - my current wesspur order is in customs clearing as I speak

 

[High Scale]

That's a pretty big shipment! Yeah I got hammered on import tax shipping the rope to the UK.

 

[Reddog]

Stig you could also check with your marine supplier that gets you the larger diameter Dynemma, Tenex is also used in marine/fishing applications.

 

[Al Smith]

.
Why can't we all just do it in centimeters, like civilized people!!!

.

QUOTE] I can pretty much do inch to metric in my head .If not though here's a neat little download that does it for you . http://joshmadison.com/convert-for-windows/

 

[stig]

Al, were you ever a Connecticut yankee at king Arthur's court?

Maybe in a former life.

Because as long as I've known you, you have reminded me of Hank Morgan,like no other

 

[Al Smith]

Now I have to google Hank Morgan .Good grief I can't even remember the story plot

 

[Al Smith]

How about that old Hank was kind of crafty . Now what's that got to do with metric measurements of a sling that was slung wrong ?

Did you know metric or not and refering to three barley corns to the inch that the English meaning the Brits ,metricfied or not still use terms of inch, feet and yard ? Ha Ha Ha .

 

[gf beranek]

By the way, Stig, was it a knot that eventually saved the day?

 

[MasterBlaster]

Now I have to google Hank Morgan .Good grief I can't even remember the story plot

Same here, and I read the Classic comic book about it.

 

[Al Smith]

I read it but good heavens that was nearly a lifetime ago .

I still can't get the simularity Stig was alluding to between this character of fiction in the writings of one Samual Clemens AKA Mark Twain and myself . Other than perhaps saying the character of one Hank Morgan was a BS artist .But then if Stig where puting me in that catagory it would be akin to the adage of people living in glass houses shouldn't throw stones.

Perhaps when the sun rises on the Danish hinder land he will further elaborate on the subject .So far it's a bit of a conundrum .

 

[stig]

No Al, he was the kind of person who knew everything about mechanical/ practical things.

That is how I see you.

It was meant as a compliment

 

[stig]

By the way, Stig, was it a knot that eventually saved the day?

Yes, the two ends of the sling were simply knotted together.
That held up fine.

I have been writing back and forth with Samson, trying to get their take on what happened.

I started out telling them that I wasn't trying to blame their product, since we loaded it past WLL, but simply trying to find out, what went wrong.

Got this answer just now, seems very plausible to me.

"Thank you for the pictures. It does look like everything was done right in this application. Honestly I don’t know why it pulled out. The splice looks to have the right length tails. If they eye were to get jammed in the block and only pull on one leg of the eye, it could pull out. This looks unlikely though since the block is very smooth. Since it was a new rope, there is a change that splice never got a chance to set correctly. Pre-loading these slings could help to set the splice and prevent the tail from pulling out in the future. “Milking” the splice can also help. To do this, hook the eye on a fixed point. Grab the rope at the base of the splice right below the eye. With a good grip on the rope, pull your hand down the rope for the length of the splice. This should help to align all the strands and pull the splice tight."

 

[FJR]

Wouldn't it make sense for Samson to "pre-load" the slings before they are sent out?

 

[woodworkingboy]

Responding to Dave's post, so rope is not like wire, where the first load sets the strands or fibers, so the rope actually is stronger the second pull?

I don't know if anyone particularly noticed, but in the heavy wire splicing vid that was posted, they set the strands with a heavy pull from both sides after completing the splice. I don't believe it is just the splice, it adds strength throughout the entire new wire.

 

[pete mctree]

At the end of the splicing procedure it is not normal to milk out the splice?( & for double braids & 16 strand etc
zero the rope - that is milking away and towards the splice over several metres to resettle the sheath & core that will have been pulled about during the process. )

 

[Al Smith]

That wire rope eye if I recall correctly was what's called a "flemish eye splice " .The ends are back wrapped around themselves to form the eye and junctioned off with a pressed sleeve which just keeps the ends tucked in .For that matter you can do the junction off with wire serving and get about the same results .

Now I've flemished and wire served a cable but it was never under a load large enough to test if it would unravel .Temporary thing,had no Crosbys with me at the time

Another method is often refered to as a farmers eye which resembles what's done on three strand lay fiber or nylon line except most wire is at least 6 strand and a beech to eye splice that way .You get done you look like you got in a fight with a dozen Tom cats at once .Of course you have swedged joints and "crosby " type cable clamps but those aren't really splices .

 

[Al Smith]

No Al, he was the kind of person who knew everything about mechanical/ practical things.

That is how I see you.

It was meant as a compliment

Thank you for that but there's more to the story .What I have which is probabley better than most but not a genious level was genetically transfered to me just by the fact of whom my parents are .

My mother was validictorian of her high school class and my dad was 4th out of 400 from Pittsburg Pa .

As far back as recorded history all the Smiths originally from England were engineers inventers ,mechanical trades people .My great great grandfather held many patents in the British Isles as did my great grandfather in this country .

Even today all the off springs including all the ladies have inherited the mechanical aptitude thing .

For years the experts disagreed about this genetic imprintation but in later years have realized just like music,the arts etc. it does happen .Thus it was with me from a young age .I didn't work at it it was just a gift of a sorts .

Even more strange is watching my two year old grandson in action .He's definately got it .

Now this is the seventh generation out from Alfred Hodskin Smith of England the farthest back I can find on the family tree .Evidently the old boy left some strong genes along those lines .

 

[stig]

Cool story.
Genes are a funny thing.
You know, the reason I compared you to him was simply that I see you as a personification of the rather old fashioned tem: "Yankee ingenuity".

 

[Marc-Antoine]

Seeing your pic in post 28, the bury of the broken eye seems way shorter than 35", as it was said previously.
The rope looks stretched between the broken out stitch and the eye, but not beyond the stitch.

Or ... we don't see the thing properly.

Try it in an other way.
There are broken strands and pull-out strands. The last ones could be well done by the whipping during the slip. So this part should be one end of the stitched part of the bury.
I don't think the "broken" strands are the entrance point of the bury, too even and well placed around the rope, like there were cut by the splicer to make the taper. As seems to show the end of the rope with his really smaller diameter, just past the "broken" strands.
In this case, the eye should be much more to the left than what you showed on the pic. And the stitch could be actually made partly in the tapered part (not a good idea).

Could you look closely to find some disorders in the strands at the left of the broken whipping twine. They could by the evidence of the real place of the bury. But it isn't obvious with the loose strands of the tenex.

 

[PCTREE]

Wouldn't it make sense for Samson to "pre-load" the slings before they are sent out?

"When you receive your Wraptor please check all bolts are tight and have enough Locktite applied to avoid potentially deadly failure"