Figuring WLL and trailer securement points

This is not a DOT spec or rating on attachment points but a simple guide. Steel used in trailer construction has a minimum strength rating of 36KSI or 36000 per sq inch. As an example say Humbles trailer the rub rail is 1/2 stock 2" high, each weld if the same material is used would have about a square inch of weld. Divide 36 by a factor of 5 to get a rough WLL of 7200 lbs. Again this is only a guide, use the 7200 lb per sq inch

This is ONLY good for steel, aluminum has other properties that make rating a point more difficult. The rating is based on a full penetration filet weld using the area of the weld, spot welds or segments need to be considered in calculating the area. This should give you a rough idea of the strength of an attachment point.

Steve

 

Humble is not talking about a rubrail.

 

Rub rail or outer rail, using the area rule the load factor can be estimated. If the outer rail is 1/2x 5" then it has an 18K capacity in the long axis. Twisting comes into play but using the 5-1 safety factor the rail may deform, it won't fail.

Steve

 

I’m talking about the outer side rail of a lowboy. Which on mine is T1 steel.

 

You could have use 5 3/8 chains and been good. 6 for a good feeling, done with three chains. Why do you get on here and spread such #########. On top of the fact Ravens were junk recycled beer can trailers.

 

I get it, I used you as an example. How many guys hauling even know what T1 is? The point is, if you know what the material is you can determine if the attachment point is up to the load.

The idea that attachment points are not rated doesn't mean you can't use a little simple math to see if the point you want to use is suitable.

Steve

 

Question for you equipment guys. I used to haul some. Don't plan on it in future. Per conversation with OSP Dot, I was told that securement over a bucket, forks, or anything on hydraulics must be secured, but did not count to securement of the load. I have always followed that. Was he wrong or am I misunderstanding it?

 

Better throw a chain over that boom if your heading to PA. They require a steel securement over any accessory.

 

I would kindly ask him to show you a regulation to back that up.

P.s. I’ve never seen anything to support his claim.