Recovery how-not-to

[Antichrist]

The big thing is to slow down, take some good deep breaths, assess the situation and figure out not only what equipment you have available, but how you are going to use it and what can go wrong. Too often people don't think about how/where a vehicle is going to move once they break it free/lift it/etc. or what might fail. This can lead to worse stucks, (further) damage to the vehicle or equipment or injury/death to bystanders.

This applies to all recoveries, no matter how simple, no matter what the vehicle is.
http://www.youtube.com/watch?v=1SarrhmmT_I

edited to fix typo.

 

[TreeTopFlyer]

....or a clue.

More important than anything else. They didn't have it.

 

[TreeTopFlyer]

I wonder if any of them had one of these in their kit?

I like the magazine better

 

[MuddyOval]

This applies to all recoveries, no matter how simple, no matter what the vehicle is.
http://www.youtube.com/watch?v=1SarrhmmT_I

edited to fix typo.

I love that link...

 

[michaelgroves]

This applies to all recoveries, no matter how simple, no matter what the vehicle is.
http://www.youtube.com/watch?v=1SarrhmmT_I

edited to fix typo.

What I've observed over the years is that the success of any recovery varies inversely with the number of people involved, once there are more than 3...

I've done a few recoveries where there is a crowd of onlookers (one involved a mini-bus which had run off the road into a ditch, and all the passengers had been trying to lift it back out). Eventually, I found the only thing to do was to identify the driver, and get everyone else to stand back a LONG way, while the two of us assess the situation at leisure and agree a plan of action. If we need more able bodies, we call on specific people from the crowd, and make their limited jobs very clear to them. No-one else gets closer until it's all done.

 

[cruiseroutfit]

Lots of great ideas and thoughts in this thread.

I've taught a couple of recovery classes for local clubs, while I'm by no means a recovery 'expert', I have done my fair share of recoveries including several high-profile off-road vehicle recoveries where we were basically called in by the BLM/Forest Service to handle a job a regular wrecker service wouldn't take. More than anything I've studied the engineering and physics aspects of recovery operations during my engineering studies. I feel like I have a good general working knowledge of the equipment, I've sold and used many different products from your basic dynamic snatch strap to high end land anchor devices. That said I'm wanting to learn more. I purchased a military vehicle recovery operations text awhile back, I've referenced it in my classes in the past but never really sat down and read it cover for cover. In fact one of the best sections is on safety, something we are all concerned with. I developed my own little mantra of procedure - S.A.F.E, Survey situation, Assess tools, vehicles and safety gear on hand, Formulate extraction need, technique and tools and Evacuate are and extract. Its simple, serves more as a reminder than gospel but helps I suppose.

Browsing through the military manual I really like their acronym
Reconnoiter area
Estimate situation
Calculate ratio (*they have some very helpful load ratios for various situations)
Obtain resistance
Verify solution
Erect rigging
Recheck rigging
You are ready

*I've found that their ratios could very well be helpful in recovery situation. If nothing else for determining the anticipated loads when recovering a mired rig or righting a rolled vehicle for example. While these ratios are just guidelines and a safety factor should be incorporated, surely they help rule out some recovery situations such as trying to use a non snatch-blocked 6k winch to rescue a wheel depth mired 8k vehicle (stuck to center of hub).

A few of their ratios:
Overturning resistance (righting a rolled rig) = Resistance is 1/2 of the vehicle weight
Wheel Depth Mire (up to wheel hubs) = Resistance is the weigh of vehicle
Fender Depth Mire (top of wheels) = Resistance is 2x weight of vehicle
Cab Depth Mire (over the fenders) = Resistance is 3x weight of vehicle
Grade Resistance = Estimate slope of grade, frictional losses and weight of vehicle to calculate resistance. With losses do to terrain (rocks, mud, etc) the grade resistance can soon exceed the vehicle weight.

Its also got some sections like 'Positioning Gun Tubes for recovery', 'Dual Wheels used as Winch', 'Patching fuel tanks and repairing radiatores', 'Remounting Tracks' and 'Decontaminating chemical defense units'

 

[cruiseroutfit]

Forgot to ask... So I'm completely in line with the thinking that a d-ring shackle of any size/rating shouldn't be used to join two snatch straps, the logic there is perfectly understandable. However, what about using a d-ring to join two static straps that are not dynamically loaded. For example say you need to do a straight-line, non-snatched winch recovery of a vehicle that is stuck in a snowbank, they are on flat grade with just their front end stuck in the snow, you estimate their resistance to be just 1/2 of their vehicle weight, so 2500 lbs. Now, instantly lets use SF of 4, so an anticipated safe resistance load of 10k lbs. Well within the capability for your M14k winch on winch layer 1 & 2. Now, in order to use your winch on layers 1 & 2 you need to use a static strap (winch extension or tree saver) to finish the distance to the vehicle. Is the d-ring the safe and appropriate means for connection there? Now what if you needed to use two 20k WLL static rigging straps in conjunction with your winch line, such as 90 ft of cable out, and two 15' static rigging straps. Can two d-ring shackles of appropriate size be used (say a minimum 10k WLL to match our 10k SF derived load). I would say yes, its within the design of all of the products and its the most appropriate and direct way to connect the cables. What do you think?

Its easy to use the math and safety factor to rule why dynamic snatch straps used while connected to a d-ring could exceed safe operations. Remember the military resistance weight for a 6k rig stuck up to the top of its wheels would be 12k. Static. Add 10ft of 'snatch' and that force could quickly multiply 2,3 4 time plus depending on the stretch of the strap, the pull vehicle, traction and the distance. So not only are you exceeding the safety factor adjusted rating of the strap(s) several times, you could easily be exceeding the stated WLL of the strap(s), failure is likely in these situations and when that strap is now loaded and coupled to a mass of considerable proportion (a 3 lb d-ring shackle), its a recipe for damage, injury or death.

I carry a snatch strap in my recovery bag, but rarely do I ever use it. If a stuck vehicle won't take a 'tow out' (ie line is tight and vehicle slowly attempts to pull), then I would rather get a winch out and setup a standard recovery. 'Snatching' involves such brutal forces to both vehicles and the strap and mounting equipment themselves. We've all seen YouTube videos of frames tearing, bumpers yanking off, etc when a truck backs up and gives a vehicle a hilarious snatch, often stopping the tow vehicle in its tracks once the strap reaches its yield length. A few weekends ago we gave our straps a real work test over the 3-4 days of wandering in the desert. Stucks and broken rigs meant lots of towing. One night one of our trip a rather heavy Scout was mired tire deep on two wheels and hubs deep on the other two. As I arrived to help he already had is snatch strap out for use. We had solid recovery points on both rigs, so no qualms there. We attached the strap and gave it several increasingly violent tugs, to no avail. It just wasn't happening. At the time I honestly though it might. Now rethinking the situation and the theoretical loads involved with a mired rig (1.5x the wight of a vehicle so roughly a resistance load 9000 lbs I was trying to "tug") its clearer to me that we should have started with what proved to be the ultimate solution, that being a snatch-blocked winch operation.

 

[JamesDowning]

Forgot to ask... So I'm completely in line with the thinking that a d-ring shackle of any size/rating shouldn't be used to join two snatch straps, the logic there is perfectly understandable. However, what about using a d-ring to join two dynamic straps that are not dynamically loaded. For example say you need to do a straight-line, non-snatched winch recovery

For static recoveries there is already a good amount of hardware used to connect the winchline to whatever. The winch hooks are of similar weight to a shackle anyways.

However the problem in your scenareo comes with using a snatch strap in a static recovery. That's a big no-no. Think of the snatch strap as a spring. As the winch first begins to pull, it will only be stretching the strap. This is preloading your entire system. When your vehicle becomes unstuck (once it pops over the rock or whatever) and the load on the system decreases, the snatch strap will continue pulling. This can lead to uncontrolled or unpredictable recoveries.

Basically, you can't not 'dynamically' load a snatch strap. Your best bet is to purchase a winch extension line or static strap to use in that situation. Concerning the use of a shackle in a static system... its always a good idea to decrease your system weight whenever possible.

 

[cruiseroutfit]

...However the problem in your scenareo comes with using a snatch strap in a static recovery.

Sorry, that was a typo in my scenario, if you read down lower I described the theoretical straps as static only. Again I'm 100% in agreement with never using a snatch strap in tandem or in a winching operation. My question is if others are OK with using a d-ring with static straps in tandem with a wire rope winching setup?

... its always a good idea to decrease your system weight whenever possible.

Very true, the damage force of a flying object is directly proportional to its mass.

Another thought, for a winch to static strap connection, are you OK with the hook only or do you prefer to use a d-ring looped through the strap loop and through the eye of the wire rope? I feel more comfortable with the d-ring, not only because it is a positive connection but also because it places a less abrupt stress on the strap (assuming your using a standard winch hook with a narrow width compared to that of say a 3/4" shackle pin or body. That said there are many different hook configurations available, some of which have both the 100% closure on the connection (like a gate on the hook) and a greater contact area with the strap for example.

EDIT: The more I think about it, while 'static' and 'dynamic' are good names for characteristics of the straps under load, I think they are a bit confusing, maybe 'elastic' and 'nonelastic' or something similar would be a better way to characterize the straps. Or mayby just 'snatch strap' versus 'tow strap, tree saver strap and winch extension strap' all of which would clearly label its acceptable recover uses? I do find it a bit troubling that some manufactures or at least their retailers don't advertise their straps either way, rather calling them a 'recovery strap' that could lead a user to assume either way.

 

[dust devil]

Sorry, that was a typo in my scenario, if you read down lower I described the theoretical straps as static only. Again I'm 100% in agreement with never using a snatch strap in tandem or in a winching operation. My question is if others are OK with using a d-ring with static straps in tandem with a wire rope winching setup?



Very true, the damage force of a flying object is directly proportional to its mass.

Another thought, for a winch to static strap connection, are you OK with the hook only or do you prefer to use a d-ring looped through the strap loop and through the eye of the wire rope? I feel more comfortable with the d-ring, not only because it is a positive connection but also because it places a less abrupt stress on the strap (assuming your using a standard winch hook with a narrow width compared to that of say a 3/4" shackle pin or body. That said there are many different hook configurations available, some of which have both the 100% closure on the connection (like a gate on the hook) and a greater contact area with the strap for example.

EDIT: The more I think about it, while 'static' and 'dynamic' are good names for characteristics of the straps under load, I think they are a bit confusing, maybe 'elastic' and 'nonelastic' or something similar would be a better way to characterize the straps. Or mayby just 'snatch strap' versus 'tow strap, tree saver strap and winch extension strap' all of which would clearly label its acceptable recover uses? I do find it a bit troubling that some manufactures or at least their retailers don't advertise their straps either way, rather calling them a 'recovery strap' that could lead a user to assume either way.

All recoveries are dynamic because you will be moving something that has mass.

Stretchy straps used for snatching are called kinetic straps. Tow straps are non-kinetic.

It is just as easy to join two non-kinetic straps by joining loops as it is with kinetic straps, so why use a shackle?

And, for what it is worth, the rolled magazine, stick, nyla-bone, or whatever, adds nothing to the strength of the two joined straps. The magazine just makes it a bit easier to take them apart afterward. However, figure-8 knots don't jam, so with or without the magazine, they will come back apart.

 

[Scott Brady]

All recoveries are dynamic because you will be moving something that has mass.

Dynamic and static are used to describe the rigging, not be descriptive of the method of recovery. Just like a static climbing rope is not static in a rappel, but describes the equipment. Winching= Static Rigging. Vehicle-to-vehicle kinetic recovery (snatch) = Dynamic Rigging.

And, for what it is worth, the rolled magazine, stick, nyla-bone, or whatever, adds nothing to the strength of the two joined straps. The magazine just makes it a bit easier to take them apart afterward.

Other than making the knot easier to take apart, the magazine (or stick, etc) decreases the radius of the rope in the knot, and limits the constriction of the knot under load. The knot is typically the point at which the rope is most compromised and will most likely fail. The smaller the radius of the rope bends in the knot, the greater likelihood the rope will fail.

 

[cruiseroutfit]

All recoveries are dynamic because you will be moving something that has mass...

Exactly why I suggested we clarify the straps a bit more.

Stretchy straps used for snatching are called kinetic straps. Tow straps are non-kinetic.

Those work too, in fact that's what I've called them in the past. Its been a long weekend. On that note all recoveries are kinetic on some level too But I digress, I like kinetic/non-kinetic just as much as elastic/nonelastic, both of which are better than static/dynamic that I'm guilty of using.

It is just as easy to join two non-kinetic straps by joining loops as it is with kinetic straps, so why use a shackle?

Ever tried to peel apart two straps attached as such after a strenuous load? Some straps simply are not designed to be attached in such a manner and their loop designs make them rather hard to split apart. They don't knot so much as they wedge together. Another reason could be the type of recovery you are doing, you might need to be able to cleanly remove a strap and quickly re-rig, a shackle makes this possible. But your absolutely right, there are situations where a simple figure 8 knot would be not only appropriate but ideal. The entire purpose of my theoretical situation wasn't to say d-rings are the definitive way to attach static, nonelastic, non-kinetic straps, rather just to see if others were OK with their use under certain yet optimal conditions.

 

[Donsfast]

What I've observed over the years is that the success of any recovery varies inversely with the number of people involved, once there are more than 3...

I've done a few recoveries where there is a crowd of onlookers (one involved a mini-bus which had run off the road into a ditch, and all the passengers had been trying to lift it back out). Eventually, I found the only thing to do was to identify the driver, and get everyone else to stand back a LONG way, while the two of us assess the situation at leisure and agree a plan of action. If we need more able bodies, we call on specific people from the crowd, and make their limited jobs very clear to them. No-one else gets closer until it's all done.

I agree with this quite a bit....Once while towing I was called to a fire truck that had fallen partially into a drainage ditch. For those that dont know what a drainage ditch is since its an odd SW thing it would be a man made canal that water originally flowed through for the flooding of farms, crops, etc. These drainage ditches all have dirt roads running parallel to them. The fire truck was driving down the dirt road when the driver for whatever reason let the fire truck drift to close, ending up with the drivers side of the extremely heavy fire truck collapsing the dirt bank and hanging off heavily angled towards the water. I showed up to find endless rescue trucks, cop cars and lots of City employees hanging out taking charge. Before I could get out of my tow truck there were a hand full of people telling me where to park and what was needed. I spent 30 minutes finding the fire chief to help getting all the people that werent needed out of there. Luckily the cops finally got sick of wasting time and made the majority of the people leave. I probably had 15 instant experts telling me how I should be winching and blocking none of which I did. Finally I had a fire truck that was on hand move into position and anchor the front of the truck at a 45 degree angle and I winched from the rear after unloading the water aboard the dangling fire truck. 15 minutes or so and it was back on solid ground. Fire trucks arent so bad since they usually have great attachment points both front and rear and are always clean. Garbage trucks on the other hand!!! They bring the suck....thanks for reading my rant!

 

[michaelgroves]

Other than making the knot easier to take apart, the magazine (or stick, etc) decreases the radius of the rope in the knot, and limits the constriction of the knot under load. The knot is typically the point at which the rope is most compromised and will most likely fail. The smaller the radius of the rope bends in the knot, the greater likelihood the rope will fail.

Absolutely! A figure of eight bend is a strong knot, but will still lose ~20% of the rope strength. (A bowline can lose 40%!). The strength of a knot is determined by the severity of the first curve in the most heavily loaded segment of the knot. As you (meant to) say, the magazine or similar prevents the knot from closing up and making a tighter radius.

 

[spencyg]

This is a fabulous thread!!

I have a question regarding liability....

Unfortunately I have had a bad situation or two in regards to being a good samaritan where "potentially" unavoidable damage was done to the vehicle being extracted by the vehicle doing the extraction. We get LOTS of snow up here in Maine, so these were both situations where an extraction was due to poor driver judgement on public roads. Both situations involved myself stopping to help a stranded motorist, hooking up the appropriate straps, and tugging them free. By "damage to the vehicle being extracted", I mean the bottom lip of a plastic bumper being cracked due to strap angle off the rear recovery loops or a small dent in a rocker panel due to being dragged back over ice. Both of these circumstances ended well enough with a courteous handshake, but I could see how things could have gone differently.

Now, those stranded on the trail, and those stranded on the side of the road present two different types of people, I know this. But the question remains, if you try and help somebody, and damage is done to their vehicle, or their person while performing such "Good Samaritan" acts, are you liable? There are Good Samaritan laws out there to protect some people in some instances, but certainly not all people in all instances. As a professional extraction specialist with professional tools, I'm certain a significant amount of liability insurance is required directly related to damage imposed on property. I don't carry this insurance and I'm not sure if my umbrella vehicle insurance would cover it either. You obviously can't be carrying around legal releases for every circumstance involving helping somebody out and its nice to think that people will just figure you're helping them out and let it go, but sometimes they don't.

Personally, I carry recovery gear to help ME and the people I'm traveling with...it stops there. I'll lend a cellphone, but thats it. Does it make me an *** in particular situations? Yes. Does it cover my *** in all situations? Yes.

Just my $0.02.

Spence