DIY Snatch / KERR

[Gunney]

Im stuck in the middle east where there is a lot of soft sand and no good suppliers.

Ive loooked at someone sending me a snatch strap, but the more I read into them the more it seems its a very very simple product for me to source locally.

Most stnach straps are 10 to 18 ton break force, 8 to 15 meter nylon ropes that are 8 braid at roughly 22 to 28mm diamiter.

Medallion An 8-strand plaited rope made with 100% Nylon. This rope has superior shock absorbency and abrasion resistance, as well as excellent strength. Medallion meets MIL-R-24337 and CI-1303.

look at page 8 and 12 of this: http://pirate4x4.com/tech/billavist... Industrial Rope Catologue (Amsteel Blue).pdf

They then have a loop spliced into either end with a protective cover on the loops.

The interesting thing is that this is EXACTLY what you would use to moor a large mega yacht. All of the moornig lines I have found here have very very similar charisteristics to the comerical snatch straps.

With a 3 strand twist providing more strech than the 8 strand braid.

So has anyone gone out and bought some think nylon with the above ratings and built thier own snatch strap?

 

[opie74]

You will find that the majority of ropes being used for kinetic ropes are actually dock line. I use a product called "Super Strong" from Samson.

The nice thing about going with a 3 strand or Plait (double plait) is the splice is a cinch. Much easier than a double braid splice which is what most kinetic ropes are made from.

But there are different "grades" of nylon. So make sure to pick something with as much elasticity (total elongation for a given load) as possible.

 

[cody c]

Interesting read, how is it price wise in comparison to the bubba rope type kinetic straps?

Also, I guess that oversizing a strap would prevent breaks, but may limit its ability to stretch, and create more of a jar when you reach the end of it, then a stretching action.

If the price was right I might be tempted to get a large and long recovery strap.

 

[Southeast Overland]

...Also, I guess that oversizing a strap would prevent breaks, but may limit its ability to stretch, and create more of a jar when you reach the end of it, then a stretching action.

If the price was right I might be tempted to get a large and long recovery strap.

You are correct. You need to have your recovery rope sized to the largest vehicle in the pull. If your rope is oversized you will not be able to stretch it enough to be as effective versus proper sizing. Preferably both vehicles will be approximately the same size which = a rope diameter good for both which = better results.

I use a 20' long recovery rope for a heavy FJC and a 55 (and that is the only length I stock). A 30' long rope will give you more reach and also more total stretch length due to the longer length of the rope but a 30' rope takes up a ton of space. My recovery bag is already jammed packed with a 20' rope.

As far as diameter I personally use a 7/8" rope which has a break strength of 28,500 lbs and is good for most mid-sized vehicles. If your vehicle weighs 7,000 lbs that gives you a 4:1 safety factor. Remember that when you are snatching you introduce dynamic loads which will be far larger than the weight of your vehicle alone.

Also consider this. A recovery rope, which has more stretch than a typical snatch strap, is much more comfortable for towing than a strap because the extra stretch gives you more cushion when your rope goes taught. I recently had to tow a Series II Rover 12 miles and the recovery rope was MUCH MUCH nicer than using a strap.

<shameless plug> Southeast Overland has a 10% off sale on all recovery gear in October, with free shipping in the CONUS on orders over $250. This includes ropes, straps, winch lines, shackles - anything recovery. Shipping overseas would be a killer though. </shameless plug>

 

[Devilmans Hand]

i helped some associates braid a fast rope made from static line before. It isn't that hard to do, but practice with some smaller ropes before hand. A second person is necessary when you start braiding with the larger ropes. make sure you wear some decent gloves when you're helping/braiding, b/c you will get hot spots.

Looks like i have another project and need to get rope with some elasticity.

check out the link
How to Make a Fast Rope for Climbing

 

[tclark]

If you had left the /Kerr off the end of your title this post would have probably gotten more attention......

 

[Gunney]

I’ve been so busy breaking my truck and myself that I haven’t really gotten around to sorting this out.


The bottom line is it’s not that easy to find things like pure nylon docking line in short lengths in Qatar, and every shop Ive phoned has told me to come and look (great Ill just squeeze that into my 18 hour work days, or would you like to open the shop for me on a weekend? )


Fully loaded cruisers, GMC’s, H2’s, F150’s and Tundras seem to be my average recovery “client” these days so I’m in need of a sizable rope.


I’ll keep this tread alive with some updates as soon as I actually get around to finding some rope.


What’s wrong with KERR? (is there a colloquialism im missing?)

 

[Master Pull]

There are a few reasons why we use a double braid rope and not a 3 strand or other type of nylon rope for our Kinetic Recovery Ropes.

-When you pull on double braid you are tightening the braids causing the rope to have a smaller diameter and larger length. In turn you are not stretching out the actual nylon fiber

-Controlled elongation. There is a delicate balance between the amount of elongation and the force needed to obtain that elongation. With a snatch strap it takes much more force to achieve elongation since you are actually stretching out the fibers. 3 strand can stretch more then double braid, which can be good or bad depending on how the rope is being used.

-Alex

 

[opie74]

There are a few reasons why we use a double braid rope and not a 3 strand or other type of nylon rope for our Kinetic Recovery Ropes.

-When you pull on double braid you are tightening the braids causing the rope to have a smaller diameter and larger length. In turn you are not stretching out the actual nylon fiber

-Controlled elongation. There is a delicate balance between the amount of elongation and the force needed to obtain that elongation. With a snatch strap it takes much more force to achieve elongation since you are actually stretching out the fibers. 3 strand can stretch more then double braid, which can be good or bad depending on how the rope is being used.

-Alex

Alex, I gotta disagree with you on this one.

You are right in that when you load a double braid rope, both the inner and outer braids tighten up. But that is not the extent of the elongation of the rope. The fibers do indeed stretch. If they didn't, then any double braid rope would work for a recovery rope. If the only reaction of a rope is from the braids being pulled tight, then there would be no significant release of the stored energy since it doesn't take much energy to pull the braids tight. I can do that by hand. Nylon is chosen specifically for ropes that need to handle dynamic loads because of nylons ability to absorb and release energy in a semi non violent fashion.

Controlled elongation... I would be interested to see the data you read that suggests it takes more force to stretch a snatch strap over a rope. The only way I can see one needing more force on a strap over a rope to achieve stretch would be on how the fibers in the strap are woven. And other than different formulations of nylon, i.e. high tenacity, nylon is going to stretch.

 

[Master Pull]

You can pull the braids tighter by hand, but not all the way tight. yes you are going to stretch the fibers out some but you are also compressing the weave. If you look at a double braid rope under tension the strands elongate some but they also are pulled together.

What I meant is that if you pull on a snatch strap and a double braid rope (that are matched for the specific vehicle) with the same amount of force the rope will elongate far greater. This allows for small controlled pulls with a rope whereas a snatch strap requires much more slack in the strap along with much more momentum from the moving vehicle to achieve the same amount of stretch.

-Alex

 

[Mace]

Another thing to think about is that most of the products like Bubba Rope have been dipped to reduce the ability of mud migrating intot he core of the rope.