Question regarding Recover Ropes.

Looking to purchase either a 20 or 30 foot recovery rope, just need to decide on what length I want.

If i went with a 30' am I able to basket it with a shackle to make it 15' or are they not designed for that.

This is the product:

http://www.gemstoneoffroad.com/products/7-8-x-20-kinetic-recovery-rope-28-600lb?variant=13403061571

Thanks!

 

You can definitely double the rope over a shackle. The question of what the ultimate strength of the resulting configuration will be is more complicated. It has to do with the ratio of the rope diameter (D) to the diameter of the shackle (d). When your D/d ratio gets down around 1 (same size shackle as rope diameter) the breaking strength is reduced by about half. If you could double the rope over a larger diameter (say a 3 inch tube bumper) the strength will be much closer to the full breaking strength of the rope. If your diameter is much smaller (imagine a half inch shackle if your rope is 7/8ths) you're at less than half the strength of the rope.

Now all that said, the factory eyes on your rope are designed to resist bending over a small diameter and they're reinforced to prevent abrasion, but they're still technically being bent around a small radius so the factory eye is likely to fail short of the full breaking strength of the rope anyway. So is the rating given to the rope the breaking strength of the rope or of the eye? We may never know.

Other than the breaking strength of the rope, the dynamic forces should be pretty similar. The dynamic elongation (stretch) of the rope in the basket configuration will be very similar to that when the rope is pulled end to end.

In the end, it's all about what you're comfortable with but if it were me, I would do my best to increase the size of the diameter over which I was bending the rope (larger shackle etc. ) and try to protect the rope where it was making contact with the shackle, but other than that, yank the hell out of it and you'll be fine.

 

I am by no means an expert on recovery equipment, but from what I understand, I think 28,600 is a little heavier than you would want to go for a recovery rope. Our trucks don't weigh enough to stretch it and allow it to work the way it was designed, I believe you would want one around the 17,000lb mark.

 

I'd contact Thor at Viking Off Road. They have a wealth of info on the subject and what I believe to be a very good product as well. Used their recovery equipment here a few times just recently.

 

This is correct. And, if you double the rope, you have 2 legs carrying the force, so you will get even less stretch.

Ideally, you want a 20' rope and a 30' rope.

 

Why do you want it to stretch?

 

To absorb shock (if jerking) and/or to add energy to the system. Pulling with a stretched rope applies more force to the stuck truck - the unstuck truck's energy and the energy from the rope wanting to be un-stretched.

Ever see a video of someone yanking while using a chain? See the mounting point of the stuck truck get ripped off the truck? Search on YouTube for some scary videos of how not to do things...

 

D/d ratios are a more complex subject when you get into elastic/kinetic ropes. first variable that you don't normally see in wire rope or nylon/Kevlar applications is that the stretch of the rope under load changes the D/d over the course of the pull (be it a straight pull, choked, or basketed). so as you pull harder, and the rope thins as it stretches, the D/d actually improves. this is a good thing. the downside however, is the stretch itself results in friction on the attachment point. in a straight pull, this is not an issue due to the reinforced eyes. in a basket however, you will rubbing the unguarded part of the line on your shackle, hook, etc.

nylon slings are very clearly rated for baskets, however, I would not use a kinetic rope in a basket.

load configurations and ratings aside though, do you really want another vehicle getting slingshot at you with only 15 feet of separation? there is a reason kinetic ropes are longer than most tow/recovery straps.

 

kinetic ropes don't apply more force. they lessen the impulse force (why chains break trucks), and apply the load at a slower rate. the same load is applied, but acceleration is reduced, thus saving parts and components.

 

Regardless of whether you are rigging slings and shackles for a crane lift or using snatch straps/ropes/winches for recovery, stick with how every component is rated and intended to be used. The forces involved are tremendous and when shit goes wrong it can really go wrong. Equipment can be destroyed and people can be killed or injured. Don't half ass this stuff. Seriously. Do. It. Right. Or. Stay. The. Fuk. Home. Period.

 

Thanks for the advice I can agree on what you are saying here, I will probably just start with a 20' then so I at least have something in case of a jam.

 

My uncle had a chain snap on him pulling something and it whipped his tailgate putting a nice long dent in it. Lucky the broken link didn't decide to sail through his rear window. I've seen a few snap all lifting vertically, and if you have seen that you won't ever use one to pull vehicles that is for sure.