UKC

What's popping hepcats,

I'd love to hear your opinions on Sterling prusik cord. I'd particularly like to know if anyone has ever had a hole melted through their rope by one, or if that's just a fairy story someone has cooked up to scare people.

You know what, let's broaden the scope... have you EVER had your day ruined by ANY kind of prusik? 

I'm just trying to substantiate a few of the horror stories I've heard about Sterling prusiks having bad reactions with certain ropes.

Thanks if you've got any wisdom to share!

In reply to Pete Houghton:

I've heard stories about human deposits being spread over an abseilers ropes by a prussik... Is that the sort of thing you were after?

In reply to Alex Riley:

No, it's not, but that sounds absolutely horrific. I guess that would smear it an impressive distance most thoroughly. I wonder what kind of effect it would have on the friction, too. 

In reply to Pete Houghton:

I've abbed over 100 pitches each on Stirlings hollow block and auto block prussik loops on a variety of rope types and diameters and I've seen nothing to cause me any concern. 

In reply to Roberttaylor:

That's grand, thanks for sharing. For the record, I've never seen anything amiss with Sterling prusiks either, but I was recently told by someone that they have a possibility of performing poorly with certain brands of rope when under rescue loads, but that exhaustive testing has never taken place, so Sterling will only stand over their product if they are used with Sterling ropes... which would cause huge problems for mountain rescue teams the world over, if they aren't committed to brand loyalty to Sterling.

This fella I was talking to didn't provide any sources to back up his claims though, so I thought I'd cast a net and see if anyone, anywhere can come up with something to shed some light.

Pretty vague, I know... but that's life, really. 

In reply to Pete Houghton:

Is there anything special about this particular prusik cord? Over any other cord you might use to make a prusik?

In reply to Pete Houghton:

Do mountain rescue teams use prusiks? I only ask because I'm rope rescue trained and we are trained to use a mechanical rope grab device not prusiks, I would have thought mountain rescue teams would be similar. 

In reply to captain paranoia:

Yes, the Sterling 8mm is one of the only, if not THE only friction cord rated for a rescue load, provided it is used appropriately, obviously. 

I'm happy to be schooled otherwise, I'd love to hear of the existence of other friction cord rated for rescue loads.

In reply to Andypeak:

Mechanical rope grabs are of course used, but so are prusiks, where appropriate, and certainly with mountain rescue, moreso than other rope rescue teams (fire brigade, coast guard, etc), there's always the question of how to safely trim weight from the gear bag.

That's where the Sterling 8mm prusik is a wonder, it is rated for rescue loads and thus can be used for certain applications in rope rescue. But it comes with caveats, such as supposed incompatibility with some rope types (apparently...), which is what I'm hoping to find out more about. 

In reply to Pete Houghton:

Every days a school day. 

In reply to Pete Houghton: I'm also curious what's so special compared to any other 8mm kernmantle 8mm nylon cord.   

I'm looking for the definition of 'rated for rescue loads ' as well, but I guess that's an extra weight to account for a second person. 

In reply to Andypeak:

Tell me about it, except every new thing I learn these days seems to just expose yet another gap in my knowledge! 

In reply to wbo2:

It's not just a weight thing, though that is course a big part of it, it's also to do with how happy the manufacturers are to stand over their products should something go wrong during a rescue and people start suing the bejesus out of everyone involved. Tedious and infuriating insurance problems.

In reply to wbo2:

They aren't the same as a standard prusik cord, they are made from Technora, a high strength Aramid fibre and has very little core which allows the cord to lay flat increasing the surface area of the cord and therefore increasing its grip on the rope. It means a typical dia used would be larger than the standard cords and they have an eye sewn in either end of the cord.

In reply to Pete Houghton:

That's fairly moot for a prusik, surely, since the rigging of the prusik can have considerably more effect on ability to hold a load, than the cord itself. That and environmental conditions. I can't see any manufacturer sensibly warranting their product against user or application error.

In reply to beardy mike:

Okay, now we're getting somewhere. Aramid (kevlar) fibres may well cut through nylon ropes. I can start to see why there are concerns.

In reply to captain paranoia:

Sewn loops and eye-to-eyes are available, to remove a little bit of the potential for human error from the equation. Which is a great idea, because we all know how much more complicated a double fisherman is to tie than literally every other knot you could need to tie as a rope rescue operator.

He said, with his tongue in his cheek.

In reply to beardy mike:

I know that their Hollowcore is Technora, I'm having difficulty finding any confirmation that their 8mm is as well. Might you have a link to back that up? Cheers.

In reply to Pete Houghton:

I'm not certain on the definition of a 'rescue load' but there are quite a few pre-sewn prusiks which are rated >20kn. Beal jammy, the edelrid aramid one, think simond even did their own-brand one. Do they qualify, or is it a special rating (e.g. tested to failure as an actual prusik rather than an open loop)?

I have a pre-sewn prusik and it got weakened very quickly around the joint (blame the sheathing, probably) so I reverted back to the old 6mm £2 cord loop. 

In reply to Pete Houghton:

On the website it says hollowblock is technora, was this what you're talking about?

https://sterlingrope.com/hollowblock2/

In reply to beardy mike:

No, the 8mm is the cord I'm mostly concerned with, but I'm still keen to hear any prusik horror stories of any diameter, if people have any to share.

The 8mm is better suited to the 12mm ropes we use, the 6mm and 5.5mm of various brands listed above by Paul Jepson bite too hard.

In reply to Pete Houghton:

Not the knot forming the loop. But the actual Prusik knot around the rope; that's where the slip-ups might occur.

In reply to captain paranoia:

Outstanding punnery aside, the point still stands. The twit who can't dress a prusik (or tie the fisherman in the first place) is the same one who'll put the rope grab on backwards. 

In reply to Pete Houghton:

My point was that warranting twits isn't a good idea.

In reply to captain paranoia:

I agree, and it's especially important to not give them the opportunity to practice their twittery on a live rope rescue. Best leave that whole business to people who know how to tie a prusik.

In reply to Pete Houghton:

These?

https://sterlingrope.com/8mm-bound-loop-prusik/

In reply to beardy mike:

Thems the fellas Mike, yeah. I should have just provided a link from the start shouldn't I, thanks for posting that.

In reply to Andypeak:

Here’s a controversial one - our team uses 30cm dyneema slings as standard kit. I don’t know anybody else who does that.
We are allowed to use Jammies or the aramid loops in personal kit, as long as they have manufactured dates etc. on the tags for inspection purposes.
The local water rescue team is allowed to make their own old-school prussiks, but they swap them out every year. (I’m not sure how they mark them to guarantee that.)

In reply to SilentDai:

Interesting, thanks for that. Those 30cm dyneema that you use... sewn loops I assume? What diameter, on what diameter of rope, for what purpose? I think there's much more leeway in their use for certain less-critical applications, such as security for edge men, work positioning for stretcher attendant, bridging carabiners to avoid metal on metal or to provide a swivel, that sort of thing... the muddy waters are mostly around their use on the main line.

I imagine your local water rescue team would copy the info on the tag that came with the reel and heat shrink it on to the cut stub of each individual prusik loop when made. Seems the easiest way to me.

In reply to Pete Houghton:

The 10mm sewn dyneema sling is used as a prussic on 10.5mm or 11mm ropes.

https://www.bergfreunde.de/camp-105-mm-express-dyneema-runner-rundschlinge/...