1. Jim Milazzo
    March 28, 2018 @ 4:19 PM

    I developed patented technology to prevent runaway trailer accidents. This technology is a bar system versus the age old chain system. My product is made and tested in the USA and is far superior to the subpar products made in China. I won the Innovator of The Year Safety Award in my home state of Louisiana, stating this could revolutionize trailer towing safety! I also have engineering data to prove it is the best and latest technology to prevent these runaway trailers accidents. A trailer should never separate from its towing vehicle. I have 50 plus years in the metal trades field. There’s much more to my technology than I can cover in this brief paragraph. I totally agree the u-haul video is totally misleading and need to be revised and or removed. The stats on runaway trailer accidents show 4 to 500 deaths per year and 15 to 20,000 injures caused by these tragic accidents!!! Something has to be done to make our highways safer so as to prevent our love ones from these runaway missals. Thanks.


  2. David
    September 10, 2018 @ 11:50 AM

    Great article! Getting the right length of safety chain is very difficult because there is so much variation in receiver height and hitches between different vehicles. Linklock.net makes a length adjustable safety chain attachment for trailers, I’d love to get your thoughts on it.


    • The Mechanic
      September 11, 2018 @ 6:32 AM

      Thank you for sending this link. I read their website and really like the concept. I also reached out to them for more information and for something to share on our site about their product. First look says this is a really great approach, so thank you again for sharing!


  3. Paul
    September 19, 2018 @ 4:40 PM

    Good data on chain strain but no direct real world data is provided showing what happens to various chain strengths with a varying degree of twist when subjected to actual strains equivalent to a de-hitching scenario between a tow vehicle and trailer. So, in the end there is too much extrapolation that I cannot use this article as a definitive resource. Yes, the best thing is to use the proper sized chain. But, the article does not definitively tell me anything more than the author’s opinion wrapped in a high degree of indirect metallurgical data.


    • The Mechanic
      September 20, 2018 @ 7:40 AM

      Thank you for visiting, reading, and thank you for the comments. You are correct, this blog is sharing experience with engineering knowledge and judgement – opinion in your words. I would love to do the testing and provide the analysis you seek. Please let me know if you will fund the project?


  4. Oliver Street
    August 10, 2019 @ 2:24 PM

    In re: the reduction in breaking strength of twisted chain. This fact has been a given since the Roman Empire. Every woman who owns gold jewelry chains can explain it to anyone who doesn’t ‘get it’. No guide to rigging for lifting is confused about the point. The fact that there aren’t more academic studies publishing the effect of a wider range of twist angles is explained fairly simply; an engineer dumb enough to waste time and money to develop complete details of exactly how bad an idea it is can’t find a grantor stupid enough to waste money to study it. I’ve also never seen a study about the effect of a knot in a wire rope, and with luck I never will.

    U-Haul videos demonstrate what’s cost effective for U-Haul dealers, not best trailer practice. U-Haul’s rentals are equipped with generous chain lengths that would be ground off by the pavement and become useless without twisting. Best practice would be to use quick links to attach a correct length of chain for the tow vehicle. U-Haul may use a higher grade of chain to offset the reduction of strength from twisting, but I’ve never looked into the chain they use. U-Haul also uses a “multi-ball” coupler pocket and a rather absurd threaded capture assembly. The pocket doesn’t fit any trailer ball well, it just fits them all vaguely adequately and the wall thickness ensures it doesn’t blow out. The threaded ball capture isn’t a better mechanism, its there to discourage customers from disconnecting the trailer to minimize theft. also assembles their double axle trailers with both equalizer links forward making the trailer sway uncontrollably by steering both axles to the heavy side instead of the normal way tha steers the axles in equal and opposite angles from the perpendicular to the longitudinal axis to steer the trailer on an arc back into line with the towbar. I’m always amazed none of the ambulance chasers has ever hired an engineer to testify and clean out their bank account for that one.
    U-Haul’s trailers also have an extremely high empty weight for their volume and rated maximum gross weight. In a world demanding ever greater vehicle fuel economy U-Haul is still renting trailers they designed for 400 and 440 cubic inch (6.5L and 7.2L) V-8 station wagons over 18 feet long burning a gallon of 100-octane low-lead every 12 miles at 29 cents a gallon.


  5. Bao Nguyen
    September 14, 2020 @ 10:03 AM

    Excellent post and info. I also found one video about people actually tested 2 types of chains (twisted vs non-twisted), and the result matches your analysis…


    • Mechanic
      September 14, 2020 @ 1:03 PM

      Thanks for the info and the link. That’s a cool test, so I’m going to post that link up in the article as well so others won’t miss it.


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