Shelf Life For a Rigging Line

chris_girard

chris_girard

Branched out member
Location
Gilmanton, N.H.
This is a carryover from another thread regarding rigging lines. 3/4" line is a line that is not often used in tree work, but is nice to have in your gear bag.

In Don Blair's classic book Arborist Equipment, he says that all ropes should be replaced after four years under ALL conditions.

I would not think that this would also pertain to a 3/4" rigging line if it was ONLY used once or twice in that four year period, would it?

So, I ask the question what would be considered a good shelf live for an occasional used rigging line? This may be a question for the rope manufacturers.
 
I trust all my seldom used rigging lines, for many years. They're kept in the garage, away from contaminants, UV and heat. I have a replaced 3/4 inch bull line that is close to 20 years old. I would have no qualms about using it if it were needed. I also have a few old poly 3 strand lines even older that I break our on rare occasions if a pull line is needed--say to do an easy pull over on a spar.
 
Don't know about longevity. I'd say that the manufacturer has the best info.

Keep it on a shelf. I believe that storing on a concrete floor is somehow bad for plastic-based ropes. Something leaches from concrete (unless I was misinformed...anyone??).

Good question.
 
My 3/4" and 5/8" db lines are stored in a cool basement on wooden shelves away from anything else.

They are both over seven years old, but I know all their history when it comes to CTF (Cycles to Failure) and know that they have a lot of life left in them.

Don't plan on getting rid of them anytime soon.
 
I have a 3/4" DB that's 6 years old and 1 that's 4 years old, both 150'. I would use either 1 for big wood and feel safe.
I still use a 1/2" DB that we used to test the 1st production made porty 2, back in 1998. This rope got sooo abused, it tore the cover apart. So, I cut out the shredded section (about 15') and kept the other 2 hanks. Don't use them for lowering anything of size. Use them mostly for stabilizing loads.
I haven't heard of a shelf life for polyester. I was told by a "Fireman technical rescue trainer" to downgrade nylon 6,6 by 5% every year. I'm not sure if that applies to tree care or just the "Rescue" industry. I will say that the 6 year old 3/4" DB (23,000 lbs. ABS) has a nylon core and I would trust it completely with a 4,000 lb. load.
 
Chris, let me know if you're too freaked out, I'll take them off your hands.

Seriously though, hang them rather than lay them on a shelf where mice, etc. might get at them.

If you know they have been babied then go with your gut, just go a bit easy. If you've got a sick rigging job, go with a new line, use the older ones for lighter stuff (like Norm said!).

-Tom
 
I'm on our campus technical rescue team (confined space, but remarkable overlap to tree climbing), and we're replacing a couple of unused ropes at (i think) 10 years, per manufacturers instructions. I agree with someone above, to ask the maker, so you don't have to ask the big one.
 
Ten years is what your manufacturer says?

Just wondering what kind of tests the manufacturers have used to determine a 10 year unused shelf life for a line.

I will check with Yale Cordage on Monday. Jamie may have some data for us.
 
Yosemite SAR tested several unused 10 year old dacron and nylon ropes and found they retained almost 100% static strength but almost all broke on the first test fall.
 
That's what Setnicka, et. al. say in "Wilderness Search and Rescue". Great book by the way, getting dated now though. The tests were over a decade ago. The ropes were dynamic kernmantle designed to handle 4-6 UIAA falls.

So yep, the bounce went out of their bungee... so to speak.
 
Is there an end to the shelf life of a rigging line? I don't hope so because one of my (almost never used) lines is 12 years old.
Ok ok. I know I probably have to ditch the rope but to me it feels like throwing away something that's still perfectly fine.
A couple of years ago we 'tested' a 8 years old Hi-Vee. We cut the rope up until only two outer strands and the core were left. The rope broke at around 1200 kgs.
Maybe it's a false faith in old ropes but IMHO lifetime doesn't really count. I always thought it was all about "cycles to failure" and never overloading the gear.
 
[ QUOTE ]
I'm on our campus technical rescue team (confined space, but remarkable overlap to tree climbing), and we're replacing a couple of unused ropes at (i think) 10 years, per manufacturers instructions. I agree with someone above, to ask the maker, so you don't have to ask the big one.

[/ QUOTE ]... our ski patrol downgrades and retires our lift evac lines at (I'm pretty sure) ten years use .... I believe the lines are perfectly good....
 
The NFPA sets a useful life range at 10 years as well. Just down graded 1600 feet of life line to work line today. All new or close to it. I would use it (except its all 1/2" CMC rescue lifeline, super stiff).
 
Here's some info that Jamie from Yale just sent me.

Hi Chris,

We recommend 5 years

I’ve heard the 10 year rule, but there are too many variables at that point.

Anything after 5 years, I would de-rate the rope and use as light duty.

Hope this helps.

Regards,
Jamie Goddard

Senior Account Manager
Yale Cordage
77 Industrial Park Rd
Saco, Maine
04072

207-710-4546 cell
207-282-3396 ext 13 office
 
I have seen plenty of speculation by climbers, some policies of rescue organizations, and a few CYA recommendations from rope manufacturers, but NO actual data about the shelf life of ropes and webbing.
 
I've seen data but it's old and applies to kertnmantle only. The upshot was, after 10 years they retain almost 100% static breaking strength but lost most shock loading strength.

It would be really nice if manufacturers would test shelf life and publish the data. Something tells me their insurance companies will recommend against that though.
 
Here's an actual break experiment I performed about a year ago. While it doesn't answer the questions raised in this thread, at least it may supply some perspective.

The pictures show two views of the rope, a piece of 1/2-inch polyester that I had to beg and wheedle off my arborist friend. It is a piece of his climbing rope that he had used nearly daily for 35 years right up until the present.

3786923110_78e100c59b_o.jpg


3786923180_270391d1ac_o.jpg


He told me he is quite sure about the age of the rope. Since he had a couple of other climbing ropes just like this one, we can't be sure about the amount of usage. This man is the poster boy for rope abuse. He drops wood on them, he uses them for light rigging, he drags them through the dirt and mud, they get soaked with rain, they freeze in the winter, they get splashed with tree paint and chainsaw oil, they get nicked by his saw and gored by his spurs, --I could go on. He has never washed a rope in his life.

The rope piece was too short for me to test properly with two bollards, so I used a clove hitch at each end, each tied around a 3/4-inch pin.
The rope broke at one of the hitches at 2754 lbs.

I had a lot of trouble with my equipment that day and had to readjust things several times after stressing the rope, once to 1900 lbs. so I suspect in a clean experiment it would have made it to 3000 lbs. If the clove hitch preserves 75% of native rope strength, then this rope has a true breaking strength of about 4000 lbs. We could reasonably estimate the original strength to be in the neighborhood of 6000 lbs. If so, then even after 35 years of heavy use and abuse, the rope still has about 2/3 its original strength.
 
You must log in or register to reply here.

New threads New posts

Back
Top Bottom