Winching, Recovery and Field Expediants

[Recovry4x4]

I wanted to start a conversation on the above. I've got the FM 20-22 which is a Field manual on recovery. It has lots of basic information and lots of more complicated information on the subject. rdixiemiller says he might be able to get this thing copied over to PDF where it can be downloaded by all. I have many a story on right and wrong ways to recover stickage. I just stumbled across this little tool and thought all y'all might want to check it out. http://catalog.thecrosbygroup.com/Calculators/Calculators/snatchblockrigcalc.htm
Its a pretty cool program that shows you the force on a snatch block depending on how its rigged. For example, if you are rigging a snatch block off of a tree and using it just to change directions of pull, you are doubling the amount of pull in the blocks hook. Of course everybody knows that when you rig a snatch block or a winch chain with a hook, the open part of the hook (throat) goes up! You didn't know that? If you didn't, the reason for that is safety. Should the hook open up (bend under pressure) it would be forced towards the ground should it let go. Here's another link wort reading.

http://www.dodgepowerwagon.com/glovebox/snatch.html

Folks die from this so lets talk a bit, learn a bit and share a bit on the topic. We can all learn from anothers mistake. I'll post more but lets get started!

 

[poppop]

A story to illustrate your point. There was no winch involved but the point is the same. Several years ago we had a fertilizer spreader bogged down with five tons of lime on it. I used a large cable I was sure we could not break and hooked it high on my large tractor to exert downward pressure on the rear wheels. The cable was forty feet long. I used a chain to hook the other end to the stuck tractor. When we started pulling it was working great, the front wheels of the tractor were of the ground and we were getting maximum pull. Then the chain broke where it went around the axle of the stuck tractor. That forty foot stretched cable with the up angle sent the hook and four links of chain through the back and front windshields of the tractor and dropped it forty feet in front of the tractor. We were very lucky that day. It missed my drivers head by six inches and his only injuries were from flying glass. He did'nt know what happened until I picked up the hook from in front of the tractor. None of us have ever forgotten this experience. Each time we hook to a large load we make sure everything is safe and that pull angle does not lead to the driver. One thing everyone needs to remember is that when a chain breaks it usually collapsizes, but a cable is like a large slingshot and when something breaks it releases all that pent up energy suddenly and something is going flying. Be safe out there!!!!!!!

 

[Elwenil]

One of the most common problems I see with winching or winches in general is the condition of the cable, and the lack of maintenence put into the cable. I am constantly horrified by frayed, crushed, and corroded cable even on commercial towing rigs. Any cable that has damage to it should be replaced. It's not a hard job, and it isn't that expensive when you think of the property damage and injury that a broken cable can do. A local tow service was going to move a mobilehome, but it got stuck up to the axles in the soft dirt under it after the wheels were put back on. They brought in a 1 ton wrecker with a single line winch to pull the 2 ton truck and the mobile home together. Not smart, but the situation got worse. Since the room was limited in the trailer park, the wrecker was parked at a weird angle from the truck and trailer. The tow driver thought it was no problem since the winch had a roller fairlead. Again, another case of torn up, corroded cable. When the line pulled tight and started to move the wrecker, they brought in another truck to tie the wrecker off to. This time it started to pull the truck a little, but because of the severe angle on the fairlead, it crushed the cable and it snapped. The recoiling cable took the west coast mirror off the side of the 2 ton and then went through the front corner of the mobilehome. It pretty much destroyed the front of the mobile home beyond all repair. Now several things went wrong, one was care of the cable. It was corroded, which means is it was not lubricated or protected. Lube can be bought from many places like www.awdirect.com Just because the winch sits outside all the time is no excuse not to keep it in good working order. Another thing wrong with the cable was the fact that it had been damaged before and not replaced. Not winding the cable properly and letting it snarl up under layers of crossed cable just bends or crushes the cable. Never use a winch in a heavy pull with the cable snarled up. A snatch block was used in when they tried this pull, but the thinking of "bigger is better" was applied and that is not always the case. The snatch block pulley, or any other sheeve wheels etc, used should be matched to the cable. If you use 3/8" cable with a pulley designed for 5/8" cable, you are going to flatten out the cable as it rolls through the pulley since it cannot support the cable correctly. Another problem was the pull angle. A roller fairlead is not a pulley. It is not designed to let you change the direction of your pull, it is mearly there to help guide the cable back into the winch and to keep it from snagging something on the truck. Lastly the main thing wrong in this scenario was the wrong tool for the job. Make sure your winch can handle the load you are putting on it. Overloading the winch itself in the case of most MV winches will pop the shear pin. But if your cable won't handle the load, it could break before the shear pin gets to. Snarling the cable is a fact of life unless you have a winch with a winder on it. There is no point in trying to prevent it, and standing inline with the cable trying to guide it in is totally useless unless there is a very light load on the cable and you really shouldn't stand anywhere near the cable if it has a load on it. If you do manage to snarl the cable and it gets wrapped back and forth over layers on the spool, you need to take it out and run all the cable out and wind it back up correctly. Here's where it gets tricky. You have to have some tension on the cable to get it to wind good. If you just wind it in by hand with no load on it, the wrap will be loose, and when you put a load on the cable it will pop inbetween the wrap on the lower layer of cable. Some folks use the weight of the vehicle to put tension on the cable, but getting it wound side by side in smooth layers can be a pain in a MV with the winch controlled from in the cab, and the winch on the front where you can't see it. Something to drag, like a sled with some ballast works good. It has to be heavy enough to wind the cable tight, but not so heavy that it is a safety problem and so that you cannot bow the cable back and forth to wind it side by side. This is also a good chance to inspect the cable for cuts, flat spots and other damage. It's also about the only time you want to unroll the entire cable. You should never unroll the last wrap of cable when pulling. Also it is important to note that you don't have the rated pulling power on the winch except on the first few wraps of cable. After that the spool gets bigger and it looses pulling power. It's not a lot, but it is something to consider if you are near the limits of the winch. There is a lot more I could probably say on the subject of cable alone. If you really want an ear full, talk to someone who runs a industrial cable crane about cables sometime. Just my .02

 

[Recovry4x4]

This is exactly where I wanted this subject to go. For some of us it's old news. For others it brings up bad memories but I hope it instills the respect and sense needed to do this kind of recovery. Thanks for sharing your experiences guys.

 

[Deuce-bigalo]

If interested I have a scanner here @ work which scans into PDF format. If you want I can see about assisting any one who needs to have them scanned. It's only got a little 50 pg feeder, but it does the trick. Let me know - depending on the amount of pages, if you send me a copy of the document, I can sacn it and then UL it to a website, my personal site or to the SS forum / webservers.

Just give me a click and I will be there to help anyway I can!

John

 

[Recovry4x4]

Thanks Deuce! I'm sending the whole manual to Robert. If he can't do anything with it, I'll send it your way.
KE

 

[Deuce-bigalo]

Sweet R4! Be there to 'help support the troops' all I can!

John

 

[wallew]

m,.jhuh

 

[gbooth]

Back many years ago I worked in the oilfields of Oklahoma Operated a Dozer when the weather got bad we would pull the rig trucks out with winches mounted on the back of the dozer. The dozer had a 1 inch cable but the trucks were weighing in at 80.000 pounds or more, snapping a cable wasn't un common. We would take old tires and run the cable through then hook up. If the cable snapped the weight of the tire would drop the cable to the ground.

 

[M543A2]

I would like to add that several of the MV's I have bought and worked on for others had a steel bolt inserted for the winch shear pin. The original pin was aluminum. Always be sure the shear pin you use is the correct material. The biggest danger is going to a material for the pin that has a higher shear load range than the original pins. This overloads the winch and cable before it shears, if it does, creating higher exposure to all to the risks we read about here. I have had very good results with buying 6061-T6 aluminum rods from McMaster-Carr and machining my shear pins out of it. I would much rather a pin shear at slightly less loading than originally intended instead of higher. I can always add tackle to increase the force. The shear pin on the main winch on the M543A2 is of special design, machined to control the area of shear and load at which it shears. My point to all is, be careful what you use for shear pins!!
Regards Marti

 

[mangus580]

When I tried using 6061, the sheared constantly.... When I bought proper shear pins from memphis, I didnt have near the problem.... I have decided that the actual shear pin strength must be somewhere in between the 2

 

[Towerguy1]

Winching is not any different than hoisting. Make shure ALL rigging used is load rated. Dont get cheep and buy the $50 snatchblock from China when you should have the $150 Crosby or other rated block. Same with shackels, hooks, straps, etc. Ive hoisted with 200 ton cranes and there is zero tolerance for not useing the proper size blocks and rigging. The same applies to winching. It only takes 1 weak link for an accident to happen.

 

[BFR]

what would an appropriate replacement line for a deuce winch?
where would you but it?

 

[Recovry4x4]

Most places that supply wire rope to the wrecker industry can provide it.. Usually every town has somebody that sells wire rope. My memory isn't what it used to be but this comes to mind; 1/2" improved plow steel, fiber core, 6x19 or 6x37 (can't recall which) right lay. It originally had 200' on the drum.

 

[Clem1226]

there are also many thoughts on how to maintain your cable and tackel. If I rember correctally the TM's and and FM's call for GAA on the winch cable to prevent corrison. The main preoblem I gave found with this is any heavy grease you apply to a winch cable tends to hold dirt and grit in the cable where ti acts as sandpaper wearing the cable and associated tackel. I have always preferred to washe the cable in say 15/40 or 85/140, any type of viscus lubricant really as long as it would wash the grit and dirt of and out of the cable and then wipe the cable as dry as possible while respooling it. There is still enough lube on the cable to prevent corrision but it wont collect nearley as much grit.

Another thought, has anyone tried the new synthetic material winch cables? I have talked with people that use them on their civilian model winches and if I rember correctally they have the same or superior breaking streingth as the same diameter wire rope but are much more pliable and easier to maintain. I will do some more research and see if I can come up with any specs for it.

 

[Recovry4x4]

Think we had a thread on the fiber rope some time back!

 

[73m819]

when you lub your cable, it is best to have it going around a sheave(pully) so that the cable opens up a bit. the real reason to lub a cable is so the strands and wires can slide as thay work and not grab. yes a side effect is a guard agenst corrosion. on hemp core wire rope it is VERY important to keep it lubed ,otherwise the core WILL pick up moisture and corrord from the inside out, this leaves a good looking cable on the outside that will kill in a heart beat. a steel core does not have this problem, but wil eat it self alive ,takeing it over pullys the are to small in dia. , this streches the inner core, breaking wires in the long run, you can tell when the inner steel core is bad by looking at the cable the bad spot will be a touch THINER, the cable will neck down then back up . in the civi world ,useing moter oil is a no no, because os the additives , thay tend to rot a hemp core and gum cable and has a very low shere stength, there is lub made for cable, it is designed with a high shere strength, made to stay on the cable and in the cable,anti crrosive, ect., you realy DONT want a dry cable going over a fairlead or pully, this will kill a cable real quick. espicaly under a heavy load .REMEMBER think of a cable as a working machine with a lot of parts that are rideing on each other. a poorly maintained or improperly used cable will KILL you

 

[Clem1226]

thanks, good to know 819, I never thought about the affecsts of mototr oil on the hemp core, as for the cable being stressed through a tackel block if dry I have always preferred to lube my gear, IE lube the face of the pully rather than lube the cable.

Of course operateing enviroment has a lot to do with how you care for your gear as well....such as in the desert you dont want to lube with anything that sand can stick too or vice versa if near the ocean an high humidity you want to use some type of corrision inhibitor and on and on

thanks

Steve

 

[73m819]

the stress goes to the inside of the cable when bent around a to small dir. in this case a hemp core is more forgiving(crushable) the steel core stretches and breaks. its the dry wires and strands interenaly that are not silding but grabing that kill a cable as it is run across a fairlead or though a pully under a heavy load,also ite real hard to lub a fairlead or pully surface that has 100 to 200ft running though it,as the cable gets wound back on clean the outer surface and wind it TIGHT, this will help keeping moisture out

 

[rmgill]

Given the weight, energy storage and maintenance of the wire rope, when I replace my winch cable, I plan on buying synthetic winch rope.