What rope

G'Day Andy.
Rope strenghts here:
Nylon Rope - Strength

With the price of Dyneema/ Plasma, I would just get a length to use as an extension. Oh wait, that IS what I have done ;)
$100 for 30m with reassurance tha tit will perform as required AND be more abrasion resistant.

Thanks all for the advice, now to do some investigating,

Dave, i saw that table and was guesstimating that 14mm would be about right.
And you really cant have too much rope, even if its to throw a canvas over etc.

Andy
To answer your question.
12mm Nylon is usually around 3000Kg breaking strain, 14mm 4000Kg and 16mm around 5000Kg Say about 1/3 or less working load. I doubt that you will find SWL for Nylon ropes as it depends upon how much stretch the application can handle for the supplier to give you a SWL.

So I'd be going at least 14mm
I don't want to tell you how to suck eggs but nylon stretches a lot and if it breaks under load, at best a frayed rope end, but at worst a D shackle, with a lot (probably a heck of a lot) of speed may be comming to a face near you.:(

But I recon that a rope hanging around has a lot more other uses than a strap etc.
You might want to consider Polyester rope, which costs more but has a lot less stretch, unfortunately you would have to go up a size to match the breaking strength of Nylon.

Cheers Glen

Thanks Glen, for the tip on polyester, it's something to throw in the back and hopefully never use, but there may be the time when the anchor point is that little bit too far.

I did a similar thing - bought a 50m length of Dyneema, and cut it in half. Half on the winch, half as an extension or other use, or replacement winch rope. Light and easy to create a reasonable splice in the field.

The ropes they use for sailing (I think polyester with a braided cover - not spectra type) are really nice to work with, and pretty abrasion resistant. Not sure how the prices/diameters would work out in the strength you are seeking though.

Nylon definitely has too much stretch. Stunned myself senseless (and probably lucky it wasn't worse) in an incident involving a long nylon rope and a hammer when I was a young bloke.
I'm very wary of elasticity in things now!!

Steve

Nylon rope is dangerous to use for winching or towing out of a bog or lifting anything.
It will stretch to it's limit and then either snap or rebound, usually with bad conequences.
Dynemma type rope is ok as it has limited stretch and will not rebound, Regards Frank.

There is NO SWL for nylon rope, it is TOTALLY banned in the Rigging, Mining and Industrial areas that involve lifting or dragging loads.
If you use Nylon rope in a recovery situation you may kill yourself or some bystander.
DO NOT USE NYLON ROPE TO RECOVER OR LIFT A LOAD.
Tie loads down, hold up a tent no problem.
Anyone here or in the retail rope industry that says it's OK to use a Nylon rope for recovery or lifting has NO IDEA of what they are talking about.
AGAIN, DO NOT USE NYLON ROPE IN A RECVERY OR LIFTING SCENARIO.
Regards Frank.