Friction problem

[nosliw]

I bought some static rope today at REI, not sure of the company, but it was about $1/ft (I can take pictures if you want).

I am making an adjustable lanyard, so I cut 10ft for the lanyard part, and 6ft for the Prussik adjustable part. I get it all rigged up and around a telephone poll, and fall back.

Thank God I had a stopper knot, the thing zinged all the way to the end! Everything is tied properly and tightened, but the dang thing won't grab...

I used some rigging rope on it and it grabbed well, but not the other way around- the new rope won't grab on the old rigging line OR my TrueBlue climbing line!

Should I try washing the rope to get some of the 'slick' out?

What should I do?

Thanks!

 

[kennertree]

Sometimes it's best to go with a smaller diameter rope for your prussik loop.

 

[ddhlakebound]

Definatley, smaller diameter rope for your friction hitch. You may also want to get a micro pulley, and use the VT instead of the prussic, allows you one handed adjustment both ways.

 

[nosliw]

it's 11mm, so i don't know if i can go any smaller and still be safe.

i'll just get some thicker stuff for the lanyard then, and hope the 11mm stuff works on that.

but a couple questions-

why won't it work on my 1/2" climbing line?

if i need prussiks smaller than the climbing line, why does 1/2" pro-master rigging line work great with my 1/2" trueblue?

 

[moray]

I bought some static rope today at REI, not sure of the company, but it was about $1/ft (I can take pictures if you want).

The problem is the "static" rope. It is very stiff and not at all suitable for making a friction knot. I would also question its use as a lanyard for the reason that the cover tends to be much thinner than you would find in an arborist rope and won't stand up to the abuse the lanyard will take. You can make a nice lanyard from 1/2 in Pro Master. There are probably ten or more cord types sold by the arborist supply houses from which you can make a good prusik cord.

 

[nosliw]

you don't think if i bought a few feet of dynamic rope for the Prussik it would hold on this rope?

 

[moray]

It might hold, but it won't wear well. Kernmantle climbing ropes don't have think covers. Arborist ropes do. You need to be careful if you want to hybridize equipment from the tree-climbing and rock-climbing worlds. Good luck.

 

[Ghillie]

It might hold, but it won't wear well. Kernmantle climbing ropes don't have think covers. Arborist ropes do. You need to be careful if you want to hybridize equipment from the tree-climbing and rock-climbing worlds. Good luck.

:agree2:

I have gotten away from using rock climbing or rescue ropes for tree work.

Most are a different construction and don't translate well. For 1/2 static line I use a 8mm prussik, a 9mm is too stiff sometimes.

But for tree work, braided lines are more supple and handle tree abrasions well. One drawback is that every thread of the braided rope comes to the outside at some point.

Kernmantle has a core (80% of the strength) and a sheath (20% of the strength) and the sheath completely isolates the core fibers from the outside abrasion.

Kind of a trade off.

I know it's nice to pop into a local store (and I have given my share of money to REI) but if you are getting new equipment for tree climbing you will end up with less hassle ordering from a arborist supply. (check out some of our sponsors )

 

[Ghillie]

In case you were wondering, the 8mm cordage I use for rock and rec stuff is rated at 4500 breaking and I have rappelled on it alone.

 

[nosliw]

good to know! i didn't know there was a significant difference!

oh well, that rope i bought today will make some nice tool lanyards...

thanks for the info guys, and yes, the sponsors will be on the top of my list; this site has already helped me so much