7/16" Sterling HTP, Tandem climbing.

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7/16" Sterling HTP, Tandem climbing.

Postby dutchcontractor » Nov 10, 2011 5:53 pm

A buddy of mine seems to think this rope is not suited for tandem climbing, I cant find anything in the specs that would keep me from tandem climbing this rope but maybe I am missing something?

Any input would be greatly appreciated.
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Re: 7/16" Sterling HTP, Tandem climbing.

Postby Chads93GT » Nov 10, 2011 6:14 pm

34.1 KN.............
PMI pit rope is 30KN.........

does having 900 more lbs of breaking strength not suit his liking for tandem climbing?

I tandem climb all the time on 10mm talon and its only 22kn.

Perhaps you should have a talk with your friend.
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Re: 7/16" Sterling HTP, Tandem climbing.

Postby dutchcontractor » Nov 10, 2011 6:23 pm

Chads93GT wrote:34.1 KN.............
PMI pit rope is 30KN.........

does having 900 more lbs of breaking strength not suit his liking for tandem climbing?

I tandem climb all the time on 10mm talon and its only 22kn.

Perhaps you should have a talk with your friend.


Maybe working load is not high enough? 766 lb SWL ?
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Re: 7/16" Sterling HTP, Tandem climbing.

Postby Chads93GT » Nov 10, 2011 6:32 pm

Id climb on it tandem and not think twice.
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Re: 7/16" Sterling HTP, Tandem climbing.

Postby Marduke » Nov 11, 2011 1:54 am

Only consideration I would give is the bounce it would have on a tandem. It has more bounce than pit rope, and could make a person sick if their partner was jerky.

But safety wise, yeah, no problem.
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Re: 7/16" Sterling HTP, Tandem climbing.

Postby gdstorrick » Nov 11, 2011 10:38 pm

Post deleted.
Last edited by gdstorrick on Jul 8, 2012 5:24 am, edited 1 time in total.
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Re: 7/16" Sterling HTP, Tandem climbing.

Postby wyandottecaver » Nov 14, 2011 8:04 pm

being 100% poly (Sterling has used "super static" in describing it) it should have less bounce than pit rope, not more.

The main issue is that it will not take shock loads as well as a typical nylon. Of even more importance, it will transfer more of those loads to YOU. While the jerkiness of tandem climbing might be construed as imposing more shock load, I really doubt that it's a factor at that scale. HOWEVER, if the rigging goes bad, then having 2 ppl on the line will of course multiply the shock load on a type of rope that will impart more force on you and your gear...which could be bad in a guts turned to mush kinda way.

I also avoid tandem climbing on principle, but I wouldn't consider this rope unsafe for it.
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Re: 7/16" Sterling HTP, Tandem climbing.

Postby dutchcontractor » Nov 14, 2011 8:24 pm

Yeah, its crazy static, good/solid rigging is essential, you want to stay very short to your backup anchors. Never use it as a belay line!

Thanks for all the input!
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Re: 7/16" Sterling HTP, Tandem climbing.

Postby snoboy » Nov 14, 2011 10:51 pm

Marduke wrote:Only consideration I would give is the bounce it would have on a tandem. It has more bounce than pit rope, ...


wyandottecaver wrote:being 100% poly (Sterling has used "super static" in describing it) it should have less bounce than pit rope, not more.


My first thought was the same as wyadotecaver's that HTP is supposed to be very static. I looked it up and found that indeed it does have more stretch than PMI Pit rope (which is also a static rope), but just barely...

7/16" HTP: Elongation at 300 lbs 1.70% [Source http://www.sterlingrope.com/product/458878/P110/_/716%22_HTP]
7/16" PIT: Elongation at 300 lbf 1.6% [Source http://shop.pmirope.com/rope/index.aspx?pageID=3&productID=1927&productMasterID=1927]
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Re: 7/16" Sterling HTP, Tandem climbing.

Postby wyandottecaver » Nov 16, 2011 6:39 pm

snoboy,

you are correct that for most caver applications HTP will have barely more stretch. However, if you look at the elongation at 10% MBS (around 600-700 lbs load) it switches to where PMI is stretchier, and the difference gets much more significant as you increase the load. 1000lbs of force is horrifyingly easy to generate when things go bad....

Real world, both will be effectively the same....unless you get into high loads like hauling or fall factors.
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Re: 7/16" Sterling HTP, Tandem climbing.

Postby Marduke » Nov 16, 2011 7:17 pm

I missed the HTP was polyester, so strike my earlier statement about stretch. But the same outcome remains, I wouldn't think twice about tandeming on it.
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