Steel core lanyard failure.

JeffGu said:
Here's the prototype I mentioned. The "tail" end has been cut off several times so that I could inspect for any damage or signs of corrosion. The last time, I added the washers to stop the adjuster from jamming into shrink tubing if it slipped, although it hasn't actually ever slipped. I did some low-height testing with hanging off of the adjuster with the thing hooked to an anchor at the other end (single rope mode) and I expected that it would slip down to the end, but it didn't. The adjuster is a dual-cam rope grab used for fall arrest, and has to be threaded onto the lanyard during construction. This one is actually the best of the lot, as far as grab power. You just squeeze it to move it, so really easy to use. Cannot adjust it under load, though, you have to take most of your weight off of it first.

The washers also allow me to pull them back, against the hose and expose the cable where it enters the last swage ferrule. As you can see, the cable looks brand new and there is no fraying, but this is the tail end. The first time I cut it apart, I redid both ends (basically rebuilt the thing) and the working end of thing looked the same, as well. It appears that the basic idea works well, in that all the reinforcing keeps the flexing away from the terminal end. It also appears that the heavy use of hose and shrink tube is not, in fact, trapping moisture and causing the cable to corrode, which was a concern I had when I started out. Of course, I don't leave them laying around in truck beds or toolboxes, and I clean them at the end of the job. I have been spraying WD-40 down into the tubing, on this one, at the tail end where I can expose the cable. I then hang it up with that end at the top so it can run down the length of the cable. I'm not sure if this is helping, or not, but it isn't hurting anything, either.

View attachment 31014

View attachment 31013

View attachment 31015

Last photo shows Permatex black silicon adhesive/sealant used to seal up cable ends. Looks a mess, but works. On others, I have used heat shrink tubing around the part of the cable that goes around the thimble, before assembling it, and that looks a whole lot neater.
Click to expand...

JeffGu, thanks so much for going to all of this trouble. Beautiful work, beautiful photographs. Great and really detailed explanations. I really can't thank you enough for doing all of this. It is greatly appreciated.

Tim
 
Thank you. It started out as just a way of saving money, but evolved into a notion that it might actually be a safer alternative. This season I'll get to put some of them to some hard use, as I have some removals booked, already. They've only had light use, so far, so I'm looking forward to beating them up a bit, this year. They're actually quite cheap to make, if you buy enough materials to do a bunch of them.
 
Hey guys,

I just wanted to mention a couple things and address some concerns relating to this discussion of wire-core lanyards. First, we did receive KevinS's petition and are reviewing it. The two wire-core lanyards we sell our Yale's Maxi-Flip and our own swaged wire-core lanyards, so we're seeing how those fit in with his petition. We'll be following up with him very soon.

The other thing I wanted to bring to this discussion, is our point-of-view on wire-core lanyards. We've sold these lanyards for a long time. There was a similar fatigue issue about 10 or so years ago with a brand of wire-core lanyards. It wasn't a brand we sold, but the fatigue issue wasn't something we considered brand specific, so we reevaluated the wire-cores we were selling. We felt they were still good to use, in conjunction with our recommendations to use a swivel snap on your wire-core if you're using a mechanical adjuster, and for frequent inspections.

Those recommendations were, and still are good, but we wanted to figure out a better way to make the wire-core lanyards. After several years, we landed on a new technique for swaging the ends which we felt was much safer than the current methods for putting the eyes on wire-core lanyards. And we still do believe this is the best way to make the eyes. Prior to launching these in our 2012 catalog, our wire-core lanyards were thoroughly tested on break machines and in the field, with excellent results. Since their launch, we've not had any reported failures.

We have no doubts in the level of our wire-core lanyards' safety, and the reviews over the years have all been positive… But, if this group is taking a hard look at wire-core lanyard setups, we're hoping you review our swaged version. As end-users, your feedback is the most critical. Does our swage method solve the problem? Could it be improved? Is there anything about it that concerns you? I'm not posting any links or part numbers; I'm after feedback, not sales. Here is a link to a PDF of the page in our catalog that explains our whole swage method, so you can see what it's all about. http://www.sherrilltree.com/site/pdfs/SherrillTree-2015Catalog-SwagePage.pdf

One last note. We're in the process of contacting a few folks who purchased our wire-core lanyard in 2012, the goal being to find a couple retired units that we can dissect and inspect. Our expectations are that we won't find anything other than the normal wear-and-tear of year(s) of service. We intend to share our findings.

Thanks, everyone!

-Sean
 
seanlarkin said:
Hey guys,

I just wanted to mention a couple things and address some concerns relating to this discussion of wire-core lanyards. First, we did receive KevinS's petition and are reviewing it. The two wire-core lanyards we sell our Yale's Maxi-Flip and our own swaged wire-core lanyards, so we're seeing how those fit in with his petition. We'll be following up with him very soon.

The other thing I wanted to bring to this discussion, is our point-of-view on wire-core lanyards. We've sold these lanyards for a long time. There was a similar fatigue issue about 10 or so years ago with a brand of wire-core lanyards. It wasn't a brand we sold, but the fatigue issue wasn't something we considered brand specific, so we reevaluated the wire-cores we were selling. We felt they were still good to use, in conjunction with our recommendations to use a swivel snap on your wire-core if you're using a mechanical adjuster, and for frequent inspections.

Those recommendations were, and still are good, but we wanted to figure out a better way to make the wire-core lanyards. After several years, we landed on a new technique for swaging the ends which we felt was much safer than the current methods for putting the eyes on wire-core lanyards. And we still do believe this is the best way to make the eyes. Prior to launching these in our 2012 catalog, our wire-core lanyards were thoroughly tested on break machines and in the field, with excellent results. Since their launch, we've not had any reported failures.

We have no doubts in the level of our wire-core lanyards' safety, and the reviews over the years have all been positive… But, if this group is taking a hard look at wire-core lanyard setups, we're hoping you review our swaged version. As end-users, your feedback is the most critical. Does our swage method solve the problem? Could it be improved? Is there anything about it that concerns you? I'm not posting any links or part numbers; I'm after feedback, not sales. Here is a link to a PDF of the page in our catalog that explains our whole swage method, so you can see what it's all about. http://www.sherrilltree.com/site/pdfs/SherrillTree-2015Catalog-SwagePage.pdf

One last note. We're in the process of contacting a few folks who purchased our wire-core lanyard in 2012, the goal being to find a couple retired units that we can dissect and inspect. Our expectations are that we won't find anything other than the normal wear-and-tear of year(s) of service. We intend to share our findings.

Thanks, everyone!

-Sean
Click to expand...
Thank you for this reply.
Do you have a recommendations for the life expectancy of a lanyard? How often should they be replaced assuming no there was no big fall, etc.?
 
This is definately an improvement over the usual method of swaging the ferrule. Personally, I don't think it addresses the issue of flex an the point where the single leg of cable exits the ferrule, but I may get one and try some comparative testing.
 
I like the construction idea that Sean showed in that Sherrill link.

I tested my old steel core lanyards in a pull up to 1750 kg. (3858 lbs), with a load cell.

Neither broke. Then cut off the plastic shrink wraps and they appeared very nice under them.

Next I'll grind off the ferrule to see if any corrosion or broken strands under them (I doubt it now) before I throw them away.

I think the problem might be, we don't know when to retire this stuff.

Maybe a retire age should be put on these things. I would have just kept using mine for 10-15 years if it looked good.

Those that might create their own constructions; you better research, research and research. Then..... strongly consider not doing it because there is likely some things you don't know or understand enough. Watch out for many stainless products, most stainless and stainless alloys will metal fatigue quite fast.
Keep in mind that you would feel really bad if you gave someone details how to make a homemade lanyard and later you hear they died from it breaking.

Those of you that are throwing away your old steel core lanyards. Aren't you curious if you lanyard is weak or not before it goes into the trash can?
Even if you don't have a load cell or something to measure the pull, why not pull on it a little with something? a mini, a truck, winch, or even mechanical advantage. Wouldn't you want to know if it popped apart with a mild amount of pressure?
 
Sean, Good post above. I like your swaged version. If it were available in 5/8 inch it is all I would use. It solves concerns of failure for me. (Wire core fails due to metal fatigue - 6,000 lb test rope still holding me.) I would still retire them every year. (Mfg rec. could probably easily be 2-3 years.)

Will you be producing any in 5/8 inch?
 
Treezybreez said:
5/8" feels better in the hands, especially after a lot of flipping. There are more strands to cut through before you realize it.
Click to expand...

I like how it flips and feels in the hands as well. for small removals and pruning i have a number of rope lanyards half inch and also a lil smaller, but for big removals and spar work, i like that big fat flipline.

Treezy, you are walking a dangerous line there. There is no additional thickness to the wire core, just the rope jacket around it. not sure exactly what you meant but that added thickness doesn't really do anything for safety, aside from maybe he stray handsaw nick here and there

-Steven
 
theXman said:
Those that might create their own constructions; you better research, research and research.
Click to expand...

In my original post, I included a disclaimer, but I'm happy to repeat... if you're not willing/able to evaluate the materials and methods used in regard to their appropriate use, then you should just buy something. I'm not responsible for people falling on their heads after trying anything like this.

However, if you are willing/able to test your materials and methods as you go along, be sure and test the commercial ones, too. That way, you can get an idea for yourself just how much engineering and testing they must have done. You're going to be unpleasantly surprised. It's much easier to pay a lawyer to write a disclaimer than it is to innovate a new product or assembly process. The flex testing will be the most enlightening of all, but even straight pull testing will surprise many folks as to which ferrule types actually hold better.
 
merle_nelson said:
Sean, Good post above. I like your swaged version. If it were available in 5/8 inch it is all I would use. It solves concerns of failure for me. (Wire core fails due to metal fatigue - 6,000 lb test rope still holding me.) I would still retire them every year. (Mfg rec. could probably easily be 2-3 years.)

Will you be producing any in 5/8 inch?
Click to expand...

Thanks for the replies everyone. I was out Friday and Monday, so getting caught up and looking up answers for everyone. But real quick, regarding the 5/8", I recall it being discussed internally not long ago. Maybe a year or so, but we weren't sure it had enough demand. However, seeing the replies here, I'm bringing it back up for discussion.

To my knowledge, the 5/8 wire-core uses the same diameter wire; the extra diameter is just from the jacket. Does that change anyone's mind, or is the 5/8 preference just about how it feels in hand?

I'll work on getting the rest of the replies answered real soon.

-Sean
 
5/8" just feels great in the hand to me. I'm good for at least two a year, four initially the second they are available. (As long as that swage allows no rope slippage.)
 
KevinS said:
Why is 5/8" the preference?
I use 1/2" or even 7/16" climbing line for my rope lanyards. They're rated OK and a bit lighter.
Click to expand...

This is why I always differentiate between a flip line and a positioning lanyard. They can certainly be used interchangeably but a flip line has very specific design components that make it superior for working a large spar with spurs. When spurring up or down a spar the flip line becomes a handle that you don't let go of, so 5/8" or better yet 3/4" is tremendously better than 1/2". The stiffness inherent in most flip lines makes a much better hoop that will pass rough bark and branch stubs with less effort than would a soft and flexible lanyard.
 
DSMc said:
This is why I always differentiate between a flip line and a positioning lanyard. They can certainly be used interchangeably but a flip line has very specific design components that make it superior for working a large spar with spurs. When spurring up or down a spar the flip line becomes a handle that you don't let go of, so 5/8" or better yet 3/4" is tremendously better than 1/2". The stiffness inherent in most flip lines makes a much better hoop that will pass rough bark and branch stubs with less effort than would a soft and flexible lanyard.
Click to expand...
OK thanks. I guess that's why I like my steel core
 
You must log in or register to reply here.

New threads New posts

Back
Top Bottom