Another line question

I'm looking at a variety of ropes for a variety of uses, but I'm currently confused (no, that's not an unusual state for me).

What are the advantages/disadvantages between 3, 12, 16, and 24 stand lines? How are the 16 and 24 strand lines different from kernmantle? They look the same to me. What is kernmantle anyway?

Also, I hear a lot about some lines not being able to hold up to the friction knots we use. Yet rock climbers use prussiks all the time on kernmantle. What makes the difference?

Can someone explain this to me or point me to someplace I can find out? If you do explain it here, please be sure to type real slow so I can understand you. I became a shrink because I couldn't get all that engineering stuff.

Doc,
There's already a pretty good explanation on treebuzz.com recently under "Climbers Talk", then under "XTC and Mech. Ascenders" of all the differences between arbo ropes vs. kernmantle and some diffs. between dif. strands.

Wow, to answer your question would take an hour of constant typing.

Your best bet is to tell us what you wanna do with the line, and we can quickly guide you to the right line.

love
nick

Doc,

I started with "On Rope" in the library. Later I purchased one. They address the basics. "On Rope" becomes my winter reading.

Searching here in the forum is a good starting point on rope topics.

Historically www.treebuzz.com has carried pdf files on important topics. I don't recall seeing a rope article there.

Thanks for the replies. Charlieb - The info on Treebuzz was very helpful.

Jim - I, too, got On Rope from the library. I haven't bought it yet, but am asking for it for Xmas (along w/ carabiners, pulleys - Oh heck. I just gave my wife the whole catalog and said "Anything" ) .

Nick - I have a few ideas in mind. Primarily climbing line. I've always heard to never use static kernmantle (like rock climbers) but haven't been able to understand why. I have a 30' length of rock climbing line that I'd like to take with me when I go backpacking, so I can get up into a tree at night. What's the concern with using this line?

Also are there any restrictions on lines for prussiks?

Thanks

Docteric,

Back when this rock climbing rope discussion began, the sheath was nylon. Nylon has a lower melt point and less abrasion resistance than polyester. Nylon also absorbs water, reducing the strength by 15%, which makes it equal to polyester at that point. I've speculated that nylon looses more abraision resistant when wet. Water plasticizes nylon, making it softer. On my last visit to the local rock climbing store, the ropes had polyester sheaths. That makes sense to me for their application. The only reason that one wouldn't use a rock climbing rope with a polyester sheath is knottability. The one rope that I tried quickly was very stiff on knotting. Would it hold Blake's Hitch? If you climb the tree exclusively SRT, it wouldn't be an issue. If you climb DdRT, then abraision resistance and knottability are the key considerations.

New England Rope's Fly and Yale Poison Ivy are static kermantle arborist ropes that are supple enough to hold a Blake's hitch and according to manufacturers description have minimal but sufficient stretch to absorb shock during a fall. When you climbed with me you descended on my Poison Ivy so you have an idea of what that rope is like. The Fly is very slightly less diameter.

So if you want a rope that will serve well for SRT and DdRT either of these will do the job. A traditional static kermantle is absolutely useless for tying a Blake's Hitch or any friction knot.

You could by a 30 ft. piece of Fly to meet your camping requirements. Wesspur has it for .67 cents per ft.:
Fly by the foot

-moss

Moss,

Thanks for the Wesspur website. I've been looking for a place that sells the line by the foot.

Much oblidged.