Complicated ropes and knots

[joel0407]

I am currently installing a winch on my Disco. I am installing it with a equalizing chain between the 2 tow points (2T WLL eye bolts). The winch will be permanently "D" shackled to the chain and I intend to always use a snatch block to double the pull strength and ease the load on the winch and hopefully lengthen it's life.

By using the snatch block I will shorten the usable length of the winch rope from 30m to 15m which I think will be pretty useless. So I want to get/make a winch extension rope.

Now I have been know to be a bit cheap but I refuse to pay extra for something simple. I figure a 8t rated winch extension strap is 8t weather I pay $200 or $50. The amount of money I pay for it wont make it stronger.

Now the cheapest winch extension strap I have found is Tiger11 for $29.

But I have found an alternative. Nobles sell Superdan rope. 24mm Superdan rope is rated at 9,9000kg and is only $1.50/Mtr. The down side is I need to buy a roll of over 200m. This is one option as I could easily sell off what I don't need on eBay.

Another option is. I was a Telstra Subie years ago and I still have a couple of 400m roles of 6mm Teltra/Paramata rope (you all know the stuff). It has a breaking strain of 5.9kn. I have been doing some reading and I found how the line is layer together effects it's strength as the strands bind to each other. The hard the pull the tighter the strands hold together.

Now the most basic thing I could do is carry 300m of Paramata rope and just run 10 lengths back and forward to make 10 times the strength but handling 300m of rope is messy and by plaiting or braiding with add strength and I could make the strength with far less strands. So this is defiantly the way to go.

Now the problem it how to splice a loop on the end.

This is not good reading while drinking. Just saying.

Happy Days.

[Barefoot Dave]

G'day Joel.
Good to see someone thinking outside the box AND asking safety questions.
You might have something there.
The easiest way is run it between 2 short poles/ fence posts then slide one end up at a time and tie a Figure 8 into either end.

Bear in mind a couple of things；
Software (ropes, harnesses etc) have a life of 4-5 years depending on the manufacturer. After that they start to degrade and weaken. How long is 'a few years ago' ?

Tying knots weakens the rope by approx 30%.

Don't join the straps metal work, use a rolled up magazine of floor mat in the join to aid untieing and give it a go in controlled situation ( noone nearby).

[joel0407]

The last thing I was reading before bed was about knot effiency. Knots are usually the weakest point. I'm not just talking about joining knots were 2 pieces of rope are tied together but the knot where the rope terminated.

I'm currently thinking of doing a 4 strand, round braid but I'm struggling to find a loop splice fit 4 strand braid as I said a terminating knot is likely to be a weak point.


Braid should be stronger than twist and 3 strand twist of the same material as parramatta rope in 24mm provides a breaking strain around 10,000kg. I just don't know what the effect of braiding 4 x 3 strand twist will be? I'm thinking stronger but I really don't know.


Happy days.

[Chops]

Times money,, etc, etc, etc,,,

Wouldn't it just be cheaper and less hassle if you just spent $30 on the extension strap?

Having said that, I know how gratifying it can be doing this type of stuff yourself
There was a thread on here that had a link to knots and stuff which could be very helpful to you, but it may just be for tying off stuff,, fishing and truck knots maybe (?).

[benji]

A properly done splice will not lower the strength of the rope. Surely the answer is out there, as there's methods to splice kern-mantle rope.

The weak point of your setup will be where it loops over at the end as the outer braids take more strain. Splicing deals with with that a lot better than a figure 8 knot (which is about the most structurally strong knot there is), but you can't splice whilst under tension which is why a largish eye would be a good idea.

Personally I'd spend the $30; but it's an interesting exercise.

Sent from my GT-I9305T using AULRO mobile app

[Blknight.aus]

An eye splice has a load factor of .9 from memory.

Any knot is .7

Via the modern day equivalent to smoke signals fromsome place other than the cave where my hat hangs.

[Ovadahill]

Funnily enough I was at a nobles yesterday trying to do the same thing but with silver or blue rope. Was told a few months ago they could set up a tow/winch extension rope cheaper than buying a strap from a 4x4 store. Turns out they were wrong. But while checking other options through their catalogue they had winch ext straps (non elastic) and tow straps (elastic) similar to a snatch strap except not rated as high..
I thought you shouldn't use a snatch strap to tow because of the stretch factor or it ruins the elasticity of the strap making it useless foe any further snatching tasks. Am I mistaken? Apologies if a little off topic.
I've since decided to purchase the appropriate strap rather than mucking around with ropes as it is cheaper and also rated as recovery gear.
Sent from my GT-I9305 using AULRO mobile app

[joel0407]

Funnily enough I was at a nobles yesterday trying to do the same thing but with silver or blue rope. Was told a few months ago they could set up a tow/winch extension rope cheaper than buying a strap from a 4x4 store. Turns out they were wrong. But while checking other options through their catalogue they had winch ext straps (non elastic) and tow straps (elastic) similar to a snatch strap except not rated as high..
I thought you shouldn't use a snatch strap to tow because of the stretch factor or it ruins the elasticity of the strap making it useless foe any further snatching tasks. Am I mistaken? Apologies if a little off topic.
I've since decided to purchase the appropriate strap rather than mucking around with ropes as it is cheaper and also rated as recovery gear.
Sent from my GT-I9305 using AULRO mobile app

How did you workout it was more expensive to setup a tow/winch extension than buying a strap from a 4x4 store?

They quoted me $1.50 per meter for 24mm Super Dan. The only thing is they usually only sell it in 200m+ rolls. I thought I could sell off the extra but they said they can contact the whole seller in the new year and they may well be able to order it by the length but it will likely cost more.

Happy Days.

[bob10]

Some instructions here, safety notice here



WARNING

• Only qualified personnel should perform this splice.
• If a splice begins to slip while in use, discontinue use of rope.
• When spliced correctly, this product meets the static strength requirements of BSEN 1891 with termination.

Splicing Guide - Kernmantle Braided Safety Blue & HiVee Eye Splice

www.jamestowndistributors.com › Home › How Tos‎

• Cached
• Similar

Note: Prior to beginning splice, slide a 5 inch piece of clear shrink tube over end and down the body of the rope. We will need this shrink tube in a later step

[joel0407]

Some instructions here, safety notice here



WARNING

• Only qualified personnel should perform this splice.
• If a splice begins to slip while in use, discontinue use of rope.
• When spliced correctly, this product meets the static strength requirements of BSEN 1891 with termination.

Splicing Guide - Kernmantle Braided Safety Blue & HiVee Eye Splice

www.jamestowndistributors.com › Home › How Tos‎

• Cached
• Similar

Note: Prior to beginning splice, slide a 5 inch piece of clear shrink tube over end and down the body of the rope. We will need this shrink tube in a later step

Thanks Bob,

Nothing on 4 strand again though.

Happy Days.