km3 ?

louis

louis

Location
pittsburgh
any of you guys ever use new england km3 static rope (11mm) for climbing (drt)w/cord I wanted to try it but everyone says only use dynamic, but I herd km3 is sort of semi-static and has more stretch than most static ropes
I like velocity and fly and i love finding new rope to use
 
I use KMIII for my access line all of the time.

Right now I'm rethinking my SRT system. If I continue to use KMIII for working SRT I'm going to add a 'screamer' to reduce the shock load on myself in case of a fall.

The best way to compare ropes strengths and stretch is to look at the companies spec sheet on their webpage. Make sure that the rope is suited for your application.
 
So, even after looking at one manufacturer's web site and their data sheets, I'm not able to differentiate.

For 7/16"/11mm KMIII (New England Ropes, Aug 2006 download):
5.1% Elongation@10%MBS 31.51kN NFPA Min Tensile

I've only used it for SRT and still, any tree gives more than I can sense the rope elongating.

On the other hand, SRT or DdRT on The Fly, which I think I DO sense a little elongation is stated at the same 5.0% per NFPA (and also spec'd at 2.5% per EN 1891). 6,000lb tensile

So, at somewhere near non-loaded, we have 0% elongation and 5% at climber's rope WLL for both. Right? But The Fly's tensile is 26kN or 85% of KMIII.

There must be two very different loading vs elongation curves. Is anyone publishing these plots? I'm sure the testing machines could produce this data quite readily.
 
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any of you guys ever use new england km3 static rope (11mm) for climbing (drt)w/cord I wanted to try it but everyone says only use dynamic, but I herd km3 is sort of semi-static and has more stretch than most static ropes
I like velocity and fly and i love finding new rope to use

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KM3 isn't made to resist the wear of moving over a limb as in DRT climbing. If you use it for DRT you'd have to use a cambium saver or false crotch. Seems like it would be a really hard ride DRT, what's the reason you want to use it for DRT?

KM3 has practically zero bounce compared to Fly. I wouldn't call it a semi-static, it's a true static. Other static lines might be harder but they're all pretty close. The Fly would be more rightly called a semi-static.
 
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I use the KM III Max. It has a tougher outter cover.

I use it both for SRT and DbRT. Very happy with it.

Here's a link:

http://www.neropes.com/techdata/km3.pdf

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Do you run it over bark or do you protect it w/ a false crotch device? I can see by the specs that the cover is tough. I thought it was a no-no to abrade a static access line while it was loaded.

I'd be concerned about the low stretch qualities for climbing DdRT. With an arborist rope you're going to get some dynamic stretch if you have a short fall or make a swing that turns out to be a little harder than you thought.
 
DbRT, I use a cambium saver.

I was using ArborMaster Red/White/Black 1/2" before.

I haven't noticed any working difference between the ArborMaster and the KM III Max, except that the KM III is lighter, takes up less space, and is, maybe, a little stiffer.

Do you know any of Pasquale family from JP?
 
Rope stretch is a very elusive number to capture. There are no industry standard methods for determining stretch. If a rope were taken right off of the loom and tested it would have much different numbers than one that were loaded to a percentage of the engineered breaking strength, then relaxed and tested again.

All of the stretch numbers are percentages of breaking strength at a given load. The load is a percentage of the breaking strength. In order to compare all of the numbers they need to be converted back to actual rope lengths per 100 feet, or some common length. Comparing percentages doesn't give the right comparison.
 
This afternoon I was doing some Google research on Yates Screamers and found an old TB thread that has some relevance here.

Here is the thread:

http://tinyurl.com/rkvqr

I got a chuckle out of my 4/11 post about adding a Screamer to a Rope Guide. Was Hubert reading TB then? :)

A couple of posts below that Burnham posts some data that he got from Samson and Robert added some info too.
 
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The best way to compare ropes strengths and stretch is to look at the companies spec sheet on their webpage. Make sure that the rope is suited for your application.

[/ QUOTE ]

--not a GOOD way, though. Recall Nick's lament in another thread, re some PMI
rope (PMI, who specialize in ropes; whose Pres. heads Cordage Inst., an industry
standards org (not a "dot org"--"dot COM"!).:

"I DON'T like that [PMI] really don't give much information about the rope other than polyester and low stretch."

)-:
 
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DbRT, I use a cambium saver.

I was using ArborMaster Red/White/Black 1/2" before.

I haven't noticed any working difference between the ArborMaster and the KM III Max, except that the KM III is lighter, takes up less space, and is, maybe, a little stiffer.

Do you know any of Pasquale family from JP?

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Pretty interesting, when I SRT on static ropes they feel much less stretchy than arborist ropes. When I've SRT'd on the Fly (hybrid static?) the bounce is significant compared to my Bluewater II static rope. Based on the specs Tom and others are posting it's in my imagination? The arborist ropes feel like they have more give compared to the static ropes I've climbed on.

I don't know the Pasquale family, I've been in JP only 20 years so I'm a newcomer :-)
 
Jus to clarify, I thought the majors accronyms we used were:
SRT
DRT
DdRT

I'm not criticizing or arguing I just want to make sure I use the same/right ones with my guys.
 
Sorry, Mangoes, if I'm the one using the wrong acronym.

Correctly or incorrectly, DbRT is what I've been using to refer to a single climbing line over a limb(or through a pulley, or through a cambium saver) with both sides of the line connected to one's saddle in some fashion.

To be safe, could someone re-post the meanings, as used on the 'Buzz, for these acronyms:
SRT
DRT
DdRT

Thanks,
Jim
 
DdRT stand for Doubled Rope Technique...with a Dee not a Bea is the convention used. Rope is draped or doubled over a tie in point, TIP, in a traditional manner.

Single Rope Technique...one rope for support
Double Rope Technique...two separate ropes for support. This could lead to confusion I think because the climber could use two SRT systems or two DdRT systems. Does it matter or are we going to send ourselves into acronym insanity? :)
 
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DdRT stand for Doubled Rope Technique...with a Dee not a Bea is the convention used. Rope is draped or doubled over a tie in point, TIP, in a traditional manner.

Single Rope Technique...one rope for support
Double Rope Technique...two separate ropes for support. This could lead to confusion I think because the climber could use two SRT systems or two DdRT systems. Does it matter or are we going to send ourselves into acronym insanity? :)

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Here's how I see the doubled rope acronyms being used in the tree climbing community. Notice the key difference between Doubled and Double Rope Technique.

DdRT - <u>Doubled</u> Rope Technique
Climbing on two sides of the rope. One side anchored to saddle the other side anchored to the saddle with a friction hitch.

DRT - Generic term for doubled rope tree climbing. Commonly used as interchangable with DdRT.

For high angle climbing (caving, rock etc.) <u>Double</u> Rope Technique covers two separate systems but is not specific enough for tree climbers. Since tree climbers usually call this double crotching, DRT is confusing for tree climbers to describe this type of tie-in.

And what about footlocking on a doubled rope with a prusik (or double ascender) around both legs of the rope? If that's called DdRT then we lose a specific term. Does it already have another acronym? How about DdRFT - Doubled Rope Footlock Technique

Suffering from chronic acronymitis,
-moss
 
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Moss,
You've elaborated nicely on the definitions.
Acronyms loose their power when they have to be defined every time their used :)

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Also, "double" is ambiguous in its general connotation, which I take to be the
sense of "double the rope, then ..."--i.e., "fold in half". "DoubleD", of course,
sounds much too similar, as for it spelling.

Given the definitions intended, I'd see the main difference between DdRT/SRT
as one of a closed/closing loop vs. a fixed line.

*knudeNoggin*
 
Didn't mean to open a can o' worms, I just saw a few DbRT's out there and I use the term in my teaching notes, if I was wrong it needed correcting. That is all. /forum/images/graemlins/blush.gif
 
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