polyprop rope ?

[stealth]

can anybody please tell me why 10mm polypropelyne rope ( the blue stuff you can buy in hardware shops) is not suitable for underground use. I am trying to convince a family member ( he is not a caver) that only proper caving rope should be used, but he believes that for very basic stuff like handlining where the rope is not put under a great loading ( for more of a mental aid than a physical aid ) it is ok to use.

 

[Dep]

For non-critical application it will do the job - I made my first ladder using sisal rope.
But I would not recommend it.

But for true PPE you need properly rated rope, there is a huge difference in breaking strain, elasticity, resistance to wear, abrasion, chemical/sunlight UV damage and so on.

You could also use old electrical cable, knotted sheets, vines and creepers amd many other things, the only requirement being that it is flexible, fairly strong and long enough.

And of course if you are seen using the wrong sort of rope people will tutt at you and shake their heads!

General accepted practice is to use old 'date-expired' caving rope for handlines, but having said that I have seen many manky bits of old polypropylene rope in caves and mines.

It's fine for pulling up on as an assist where there are no good hand-holds, but I sure as hell would not lean out over a proper drop holding onto it as it frays badly!

 

[cap n chris]

Have you tried using wet or muddy polyprop rope? - it's useless since you cannot hold on to it; also, because people are often purchasing it "because it's cheap" they also purchase narrow diameter polyprop (since it's even cheaper!), thus meaning that it's even more pointless as it's extremely difficult to use it without it cutting into your hands (or snapping). Polyprop rope tangles easily, doesn't swathe/skein well, cannot be used with any devices and doesn't hold knots well without them becoming hard to undo.

Polyprop rope?

Don't do it.

Get yourself some (say about 15 metres) semi-static 10.5mm EN1891 kernmantle rope. (Should budget around £1.20 [max] per metre, i.e. about £18). It's the dogs.

 

[cap n chris]

Have you tried using wet or muddy polyprop rope? - it's useless since you cannot hold on to it without it cutting into your hands (or snapping). Polyprop rope tangles easily, doesn't swathe/skein well, cannot be used with any devices and doesn't hold knots well without them becoming hard to undo.

Polyprop rope?

Don't do it.

Get yourself some (say about 15 metres) semi-static 10.5mm EN1891 kernmantle rope. (Should budget around £1.20 [max] per metre, i.e. about £18). It's the dogs.

 

[Les W]

Polyprop is very strong but has a very low melting point and very little abrasion resistance.

It is not normally used in caving because it doesn't last very long in a cave environment.
It is NOT used for SRT as it has broken in use with fatal results also as it tends to be hawser laid it has a tendency to untwist which causes the person to spin round on the rope. 

 

[graham]

Or to put it another way, it's dangerous crap.

 

[damian]

10mm Mammut Performance Static = 88p per metre from Caving Supplies.

15 metres is, therefore, £13.20.

Your life's worth that ... isn't it?

 

[whitelackington]

Y not make your own rope ladders, u could get some second hand rope off a farmer for next to nowt, cut up some trees to make the rungs, the whole lot for under a quid :blink:

 

[stealth]

I personally use 10mm mammut performance pro rope bought from caving supplies.

I have used polypropylene rope years ago and as you said capn chris once it gets wet you have no grip. Plus its a bitch to undo when its been knotted If I remember rightly I used it the first ever time I went down GC on my own (15+yrs ago) and it was a psychological aid more than physical.

At least my family member now has info from you guys and he may stop going on about how good poly is

 

[Bob Mehew]

from http://www.ropesandtwines.com/sizes.asp I estimate that 10 mm polyprop has a static breaking strength of around 1600 kg.  Typical SRT rope (made to meet BS EN 1891:1998) must have a static strength of at least 22 kN or in round terms 2,200 kg.  Typical manufactures data indicates strengths above 3,000 kg. 

I have not got data on polyprop's ability to withstand dynamic forces, perhaps it is worth a go.

Bob

 

[AndyF]

IIRC there was a fatality in GG as a result of an abseil on this rope causeing overheat and melt..

Fine for a dig hauling ope, but absolute no-no for life critical...

 

[Dep]

from http://www.ropesandtwines.com/sizes.asp I estimate that 10 mm polyprop has a static breaking strength of around 1600 kg.  Typical SRT rope (made to meet BS EN 1891:1998) must have a static strength of at least 22 kN or in round terms 2,200 kg.  Typical manufactures data indicates strengths above 3,000 kg. 

I have not got data on polyprop's ability to withstand dynamic forces, perhaps it is worth a go.

Bob

Sounds about right.
Now take those two ropes - use them for a year and test again. I would expect to find that the SRT ropes is still approx the same  - but the polyprop?

 

[Peter Burgess]

10mm Mammut Performance Static = 88p per metre from Caving Supplies.

15 metres is, therefore, £13.20.

Your life's worth that ... isn't it?

Never mind your life, it's worth it just to save a twisted ankle.

 

[cap n chris]

now has info from you guys and he may stop going on about how good poly is

Just ask this question: if polyprop is so good for ropework applications, why don't cavers use it?

 

[graham]

can anybody please tell me why 10mm polypropelyne rope ( the blue stuff you can buy in hardware shops) is not suitable for underground use. I am trying to convince a family member ( he is not a caver) that only proper caving rope should be used, but he believes that for very basic stuff like handlining where the rope is not put under a great loading ( for more of a mental aid than a physical aid ) it is ok to use.

The problem with this debate comes right back to the attitude of your relative as expressed here. Always remember that a mental aid, as you put it, can very easily turn into a necessary physical aid and, regardless, people will use what is to hand. That is why you should always completely retire old kit and not fool yourself that you will never use it in a safety critical role if you have it with you. Just about the only exception to this is digging rope.

 

[Dep]

...
Just about the only exception to this is digging rope.

Even that can be critical when swaying up buckets of spoil etc etc...

 

[Peter Burgess]

Our club used to have many metres of what were always called hairy polyprop. Nobody liked it - it was hawser-laid, stiff, horrible to handle - the only reason I think we had it was that someone could get it cheap for us. If I recall it was 'lorry rope'. All history now - even if it had been safe, it was dreadful stuff to carry about and use.

 

[graham]

...
Just about the only exception to this is digging rope.

Even that can be critical when swaying up buckets of spoil etc etc...

Quite agree, it was a qualified exception.

 

[stealth]

Yep Another ?

Is climbing rope the same as caving rope or are they both made differently?

 

[Stu]

They are the same AND different at the same time! Climbing rope or rather the core, is for want of a better description "baked" which has the affect of shrinking the core filaments. This is what give climbing rope its elongation. Both made of nylon, both have a core/sheath configuration - though different ratios.