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Bayou Surface Drive, LLC
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7,077 Posts
Discussion Starter #1 (Edited)
(updated 3-13-07)
Vehicle Recovery
"When You Stop Respecting It, It Will Kill You"
This is for people who do it the wrong way. Quote from Billavista's Tech Article
I first off want to say I got this information from other web sites, and have simplified it to where most people can understand. There are 2 common types of recovery that most people use; Jerking and Winching. Both of these have their advantages and disadvantages. I will explain to the best of my ability the safe and proper way to extract a stuck vehicle.

Jerking is probably the most common type of recovery because most people have a tow strap in their rigs. Although a “tow strap” is not what you need to recover a stuck vehicle. Tow straps are for flat easy towing of a vehicle, not jerking of a vehicle. You need a recovery strap, because of its ability to stretch can help rebound a stuck vehicle with its stored energy when it comes back to its normal state. Use a strap for the amount of pulling you plan using it for. You need to calculate the weight of your rig and add other variables; I cannot determine this for you. Do not use straps in combination with chains or wire rope and do not fasten 2 straps by knotting them together. I don’t recommend using 2 straps together. If it is absolutley necessary to join two straps together, use a square knot to join the two.
here is a square knot and how its tied. Easy to join and easy to separate without fear of forever tied straps

Make sure the strap has a label stating its strength and manufacturers information stitched in the webbing. Your rig has to be able to handle all these pressures of being jerked. Use suitable tow hooks that are properly fastened and can handle the load. Do not use a trailer ball as a recovery point as it can break and become a missile. I recommend a “D” Ring shackle of some sort in the receiver hitch as a suitable location. See bottom of page for load ratings. Do not rig to any suspension or steering components as failure of these components can cause harm. Take care of your straps by keeping them free of water, dirt, or harsh chemicals including sunlight. If your strap happens to become soiled, wash it out with water then allow dry completely, and store it in an appropriate location. As you use your strap it may develop cuts and tears in it. It will be up to you when to deem it unusable. If there is any doubt, the strap probably should not be used on your next outing.

Some people also like to use big rope for recovery which is fine too, so here is what you need to know. How to make an eye splice, and the ropes strength. a knot reduces breaking strength by 40% while a splice retains 95% of the ropes strength. Most people say the rope will break before the eye splice will come apart. here is a picture of the splice, literature will follow.

Step 1--Tape the ends
Cut rope will have been sealed with a hot knife to prevent the ends from unraveling. To make a splice, you need to unravel a short length of one end, but you do not want the individual strands to unravel. Put a couple of wraps of masking tape around one end of the rope and slice through it with a sharp knife to cut off the melted end. Untape the rope and tightly tape the ends of the three individual strands.
Step 2--Unlay the strands
Pick one strand--it doesn't matter which--and unwind it, making eight revolutions around the other two. Tape the rope tightly just below where this "loose" strand joins the others. Now untwist the other two strands.
Step 3--The first tuck
Form a loop in the rope the size you want the eye. The splice begins at the wrap of tape on the rope, so this marks the closing point of the eye. If you are doing an anchor line, make the loop tightly around the thimble. I generally secure the thimble in position with a wrap of tape on each leg.
With the loop formed and the unlayed end on top of the standing part and pointing away from you, fan the unlayed strands naturally, i.e., with the center strand leading directly away from you, the right strand spread to the right, and the left strand spread to the left.
Commit to memory that the first tuck is always the center strand and you will avoid confusion in the future about the start of splice. Lift a strand on the standing part of the rope at the point where you want the eye to close and tuck the center strand under it. On smaller and/or soft-lay rope you will be able to make the tucks just using your fingers. Large, stiff, or old line may require use of a fid or marlinespike to open the strands in the standing part of the rope.
Pull this first tucked strand all the way through so that the eye is closed, but don't pull so hard that you distort the lay of the line.
Step 4--The second tuck
The second tuck is always the left-hand strand. The strand on the standing part it goes under is the one above the one you just tucked the center strand under. I remember "left-above" to keep me straight. Again, pull all of the loose strands through.
Step 5--The third tuck
This is where you are most likely to go wrong, so be careful.
If the left strand goes under the "above" strand, then the right strand must go under the below strand. The confusion is not which strand, it is which direction. All tucks go right to left. The easy way to avoid doing this wrong is to flip the eye over to tuck the third strand.
Once this third tuck is made, pull on all three strands in turn to snug the closure of the eye evenly.
Step 6--Over and under
The rest is easy. Pick one strand and tuck it under the strand on the standing part that is two above the one it is already under. In other words, each strand goes under one strand, over the next one above it, then under the next above that. Tuck each loose strand in turn, one tuck at a time. Turning the rope counterclockwise about a third of a turn after each tuck will help you keep the sequence and the strands straight.
Give each strand a total of six tucks. Once all of the tucks are completed, place the splice on the floor and roll it back and forth under your foot to smooth it. Then loop the eye over something and put a strain on the line. Cut off the projecting "tails' of the strands and the splice is finished. literature from Don Casey at www.boatus.com
finished product tested
PICT0826.jpg


Winching is another commonly used recovery tactic. This consists of an electric or hydraulic motor that turns a set of gears on a drum to pull or hoist a load. There are many ways to rig your line to increase pulling power of your winch, when needed. Make sure your equipment can handle the load your winch can. If not this could cause harm. Quote from Billavistas article on www.pirate4x4.com about wire rope“The minute you stop respecting this, it kills you ”. If you want all the glossary of terms on wire rope read Billavista’s tech article on Pirate 4x4. Common tools in winching are winch, Wire rope (cable), Clevis’, Hooks, Chain, Snatch Blocks, and tree trunk protectors. All of these combined can make your winching extraction easier.
Here is the required calculations you should do before winching.
Know the weight of your rig fully loaded on the trail, because there will be times when the pull you have to make will exceed the pulling power of your winch. Most winch manufacturers will recommend 1.5 the weight of your rig but frankly sometimes it’s not enough. There are 4 things you need to consider before winching.

SURFACE RESISTANCE:
A pull of 1/10 LW will cause a free wheeling truck to move on a hard, level surface.
A pull of 1/3 LW will cause a free wheeling truck to move on a softer surface, such as grass or gravel
DAMAGE RESISTANCE:
A pull of 2/3 LW will be required to move if the wheels cannot rotate (as if the brakes were fully applied), the pull required to overcome the resistance (drag) the truck id 2/3 or 67% of the LW. Damage resistance includes surface resistance (i.e. you only use one or the other)

STUCK RESISTANCE:
A pull of 100% of LW will be required if the truck is stuck to a depth of the sidewall on the tires.
A pull of 200% of LW will be required if the truck is stuck to the hubs.
A pull of 300% of LW will be required if the truck is stuck to the frame.
Mire resistance includes damage resistance (i.e. you only use one or the other)

GRADE (SLOPE) RESISTANCE:
Upgrade (vehicle has to be recovered up a slope or grade)
15 degrees - add 25% of LW
30 degrees - add 50% of LW
45 degrees - add 75% of LW
Vehicle recovery on level ground - no correction
Downgrade (vehicle has to be recovered down a slope or grade)
15 degrees - subtract 25% of LW
30 degrees - subtract 50% of LW
45 degrees - subtract 75% of LW

With these calculations you can see how much weight your winch will need to pull. Here is how to calculate it:
Add surface or damage or mire resistance and grade resistance, and this is your final figure or rolling resistance. This is the amount of pull the winch must apply in order to recover the stuck vehicle.
For those who didn’t get this here is an example:
My trail rig fully kitted out weighs in at 5000 lbs. I get stuck down a rock ravine that's about 45 degrees steep, and there are big rocks up to the frame hanging it up. Rolling resistance is 5000lbs x 3 + (5000 x 0.75) = 18,750 lbs. As you can see, this is significantly more than the 5000lbs x 1.5 - 7500lbs the manufacturers would have you believe. You may be wondering how one could ever possibly recover the vehicle in this example, given that the largest commercially available 4x4 recovery winch is 15000 lbs and that most are in the 8-9000lb range. The answer is by using multi-line rigging, which we shall explore in a moment.
Multi line rigging is what increases your pulling power. This requires the use of snatch blocks to increase mechanical advantage. There is double line and triple line rigging for times when needed.
Double line rigging:
Consists of using (1) snatch block at a recovery point and having wire rope go to recovery point and back to stuck vehicle.
Triple Line Rigging:
Consists of using (2) snatch blocks, one at recovery point, and one at vehicle. The wire rope goes from winch to recovery point, back to vehicle, and back to recovery point.
For more information on winching techniques please visit Warn’s website at this link http://www.warn.com/corporate/images/90/UserManualSRC.US.readers.pdf
I hope you can take this information and add some common sense to your mind and make your vehicle extractions safe.
Note: all credit was given to people who actually wrote some of this information. I did modify some information to make it user friendly. Information was resourced from Billavista’s Tech article from www.pirate4x4.com Please refer to it for further detail but this the most critical info I thought we could use.

Shackle Information Chart. From http://www.chicagohardware.com/catalog/09_10_shackles.pdf
Here is a pic for those who do not have Adobe reader.
shackleloads.jpg
 

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DeepSouth Gangster
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5,669 Posts
Re: Vehicle recovery (please Sticky this)

Before I read your Bibliography, I was about to call you Marcus-Vista.:crazy:

In all seriousness this is a thread everyone should read, mall crawlers or weekend mudders. You never know when you are gonna be called to pull out or you call to get pulled out.:read:

Sticky vote: *
 

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Bayou Surface Drive, LLC
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7,077 Posts
Discussion Starter #5
Re: Vehicle recovery (please Sticky this)

throw some info up about straps, land anchors, and such and sticky that sun bitch :D
lIKE MENTIONED IN THE THREAD READ THE TECH ARTICLE ON PIRATE FOR MORE DETAIL
 

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Registered
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115 Posts
Re: Vehicle recovery (please Sticky this)

I printed out the Pirate article and put it in my bag of recovery equipment. It's always in my truck.
 

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Bayou Surface Drive, LLC
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7,077 Posts
Discussion Starter #8
Updated with a few quotes. I have seen a few improper recoverys lately, so i felt i should include a few things to be highlighted in the article. Go read this
Edit: put shakle load information chart in it
 

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submarine z71
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1,310 Posts
ive seen a dring go through a guys front and back winshieldm and miss him by 6inches....dude backed up bumper to the top of a tailgate on a boy and the drunk bastards in the short truck threw it on top of the ball.....bad part was there was like 10 ppl in the back of the truck the dring hit, but right before that pull they all jumped out
wish i had a vid
 

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Registered
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87 Posts
man i wish i had a camera and a dollar for all the times i have seen people hook these things up wrong. I for one have seen(well it was more like a blur went really fast) and heard the snap of a winch able snap and crack the nearby rocks. (Johnson Valley, CA on the Hammers)

One of the scariest da** things I've experienced. The thought of being beheaded or sliced isn't very appealing!
 

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not at the table carlos
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1,244 Posts
whats a suitable stregth for a strap pullin out a full size?15,000- 20,000lb?
 

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Bayou Surface Drive, LLC
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7,077 Posts
Discussion Starter #16

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I don't wear underwear.
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622 Posts
Just thinking out loud here but, using a snatch block(s) to double or triple line rig, wouldn't you technically only be increasing the strength of your cable and not actually increasing the power of your winch? When using a free vehicle to recover a stuck vehicle and using a rope or strap, you could double it to increase the strength of your rope/strap but if the free vehicle doesn't have enough strength, then it's just not happening. See where I'm going?
 

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Bayou Surface Drive, LLC
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7,077 Posts
Discussion Starter #18
Just thinking out loud here but, using a snatch block(s) to double or triple line rig, wouldn't you technically only be increasing the strength of your cable and not actually increasing the power of your winch? When using a free vehicle to recover a stuck vehicle and using a rope or strap, you could double it to increase the strength of your rope/strap but if the free vehicle doesn't have enough strength, then it's just not happening. See where I'm going?
I see what you are saying, BUT think of a pully setup you are increasing the mechanical advantage. I see your point about doubling a rope, But it is still like a chain, (only as strong as its weakest link). I see your point because when you double a rope you make one rope when the two ends are shackled together. It is not the same when snatch blocking with winch line because the line never doubles it just changes directions to lower the ratio at which the winch is pulling and therefore increaseing the winches pulling power, but drastically slowing the line speed at the end to a lower speed. So no you are not doubling the strength of the cable/ winch line.
 
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