Ratcheting tie downs BROKE in transit!

[Dargo]

av8r, you are more knowledgeable on chains than I ever have been. Yesterday I called a friend of mine who owns a towing company. He told me pretty well exactly what you stated. I took his advice and ordered what he told me. He told me to spend the extra money and go with the US made grade 80 chain with the factory welded on hooks and the higher quality US made 9,200 pound rated ratcheting load binders. He told me that with heavy loads that do not have suspension (tractors) that a chain that will allow some stretching would be my best setup. He said that the grade 80 chain will stretch enough to prevent a sudden jerk from snapping it, but with the ratcheting binders will still hold a load tight. He told me that a grade 60 or 70 chain is strong, but he has had some break with an extreme sudden yank, as they do not have any flex ability. Well, he told me that he uses 5/8" grade 100 for his larger jobs like towing a semi and such. I don't think I need that.

stevenf made a very thoughtful post that pretty well explains my thought now on my tie down equipment. I just feel stupid for having to have a nearly disasterous close call to recognize how unsafe I've been. I really should have investigated and researched what I needed more. I can't stress enough how mistaken my thoughts were and how hard headed I'd been when my father had told me that he wouldn't use straps to hold down any tractor of his. /forums/images/graemlins/frown.gif

I learned my lesson. Anyone should feel free to use me as a "moron" who wouldn't listen to good advice that was given to me for my own good. I won't go on anymore about this incident, but I'm just thankful that I'm not dead, in jail, or worse, because of my ignorance. As I'm sure is obvious, that won't happen to me again because of my improper securing equipment. Be safe!

 

[Av8r3400]

The grade 80 and 100 chains would make great towing or pulling chains, but having "stretch" is not a good thing in binding. If a sudden jerking motion is causing a breakage possibility, a larger size chain should be used. Grade 70 binder chain is cad plated for corrosion resistance and the 80-100 is not. These lifting chains are soft and corrode quickly and loose allot of their strength because of the corrosion. They can also wear quickly with dirt or grit in the links actually grinding away the thickness of the chain.

 

[HickoryNut]

Always use more on the front than on the back, bigger chain, more straps, whatever. If something breaks, as you just experienced, you want to make sure its on the back.

C'mon, deep down, you knew those straps weren't making your tractor as one with the trailer. You'll be pleasantly surprised how chains take out all the bouncing and lurching.

 

[keeney]

Were the straps rated for 10,000 lbs working load, or 10,000 lbs ultimate failure?

If they were only rated for 10,000 lbs ultimate failure strength (which would be a working load rating of maybe 3500 lbs), then they were too small for a 7000 lb tractor to start with!

As other poster have pointed out, the jerking of going over bump combined with the leverage due to the angle could easily momentarily generate more than 10,000 lbs of force.

Another issue is how tight were they to start with? Contrary to another poster, I think its safer to have the tie-downs very tight, compressing the loaded vehicles suspension and tires as much as possible to avoid the bounce-rebound jerk effect that can happen. Imagine a very-loosly tied-down vehicle with a bouncy suspension and soft tires happily bobbing around on the trailer. Hitting a big dip, it bounces down to the point of putting slack in the straps and then back up high enough to WHAM! hit the limit of the tie-downs, generating several G's of deceleration. Contrast that to something tightly compressed, barely moving at all where the load cannot get up any significant momentum.

The G forces are what kill. A simple rule of thumb to calculate G forces is the ratio of acceleration distance vs. deceleration distance. If your tractor can bounce down 2 inches and then on the rebound is stopped short by the tie-down with only 1/2 inch of stretch in the straps, the ratio of 1/2 to 2 inches is 4X or 4G's.

- Rick

 

[MrJoe]

Thanks for the post! That's one story I woun't forget. I was just about to buy some straps, think I'll stick to using them for other cargo. Glad you and everyone escaped unharmed, you don't often get away with such a close call /forums/images/graemlins/shocked.gif

 

[stevenf]

I'll relate something I did this weekend that I know I shouldn't have been doing but it worked. I was using an old 100ft long 5/8 twisted nylon rope to get some flood remnant trees out of my lake with as it is easier to work with than chains especially when my youngster and wife are in the lake doing the attachment and its a spring fed lake so still quite cold. I realize that nylon rope is not the same as a strap but I was pulling these trees up to my burn pile about a 100 yards from the lake and when I got them there and made ready to untie them to leave them by the burn pile I was starting to back up to relieve tension on the ropes and stopped in neutral for a moment the rope pulled the tractor backwards at least 20 feet up hill who'da thought nylon could stretch that far without breaking. Course as attachment to a trailer with a nylon strap is concerned I'm sure you wouldn't get this kinda stretch but it sure seems bad to be attaching a in my case 10,000+lb tractor and implement to a trailer with and expect it to be firmly attached for transport.
Steve

 

[Bowhunter]

Dargo I'm happy to read that no one was hurt! I had a similar experience in '98 before I knew much of anything about pulling trailers. I didn't have anything break, but had too much load on too short of a trailer. Hardly any tongue weight had the trailer throwing me all over the road like it did you. Going into a blind curve on S.R. 64 was no fun at all. Luckily no one was coming around the curve until well after I ended up in the ditch on the wrong side of the road.

I have been using straps for my small tractor the past couple of years. This post has me in the market for chains. Thanks for sharing your scary experience.

 

[Henro]

While it is written for securing cargo in aircraft, this following link sure seems to relate to securing a tractor to a trailer as well.

I found it an interesting read and good learning for someone like me with no trailering experience...

Seems to fit into this thread pretty well:

PRINCIPLES OF CARGO RESTRAINT

 

[slowzuki]

Excellent document Henro.

 

[Dargo]

Thanks Henro. I printed out the entire article. /forums/images/graemlins/blush.gif