Help me understand the DOT securement laws

[bdog]

The DOT states that a piece of machinery over 10,000 lb must be secured with a minimum of 4 chains.

They then state that the combined working load limit of all the chains must equal at least 1/2 the weight of the machine.

Any chain directly tied i.e. from the trailer directly to the machine only counts as 1/2 it's WLL. If the chain goes from one side of the trailer, over the load, and to the other side of the trailer it gets the full WLL.

So if I had a 20,000 lb machine and put a 5,000 lb chain on each corner from the trailer to the machine it would be 4 chains counted at 2,500b each so 10,000 lb combined and legal.

I understand the law but in this scenario one would have 10,000 lb of WLL holding the machine from moving forward (the two chains in the rear). How is that deemed adequate to restrain a 20,000lb machine?

 

[bindian]

When I took my CHL test, I remember it as being the load has to be secured equal to 1.5 times the weight of the load. So a 10,000 pound load has to have chains securing it equal to at least 15,000 pounds. I don't remember about a minimum number of chains. Tractors need to have at least 2 chains and each attachment at least one chain. So a tractor loader backhoe needs secured in 4 places.
hugs, Brandi

 

[RedNeckRacin]

Iirc, Factor of safety on min breaking strength of chains is 3 to 1. You are better off putting more than the minimum on. I don't agree with the 1/2 wll rule at all. That chain is rated for x weight, it doesn't matter how it's secured, any section will hold that x weight. Look at a sling, a single line is rated at x where a basket is rated at 2x, which basically says the dot is being super conservative on their ratings.

 

[downsizingnow48]

When I took my backhoe from Virginia to California I spent a lot of time trying to figure this out. Ended up with six 10 ft G70 5/16 chains and six binders. Two making a vee in the front, two making a vee in the back, one for loader and one for backhoe. It meets the 10k standard. It was way overkill for a 4k B21 but doesn't cost that much considering what might go wrong in a 3000 mile trip.

 

[dsgsr]

I think you will find that A piece of equipment must be secured on all 4 corners and at each corner the tie down ( in this case) chain has to have a WLL (working load limit) equal to 1/2 of the weight of the piece of Equipment. There are other regs. also about spacing of the chains relative to the length of the piece of equipment. The Federal regs. are a minimum. Your state may have more strict regs. such as crossing the chains, chains on a backhoe buck, loader bucket, etc.

David

 

[bdog]

When I took my CHL test, I remember it as being the load has to be secured equal to 1.5 times the weight of the load. So a 10,000 pound load has to have chains securing it equal to at least 15,000 pounds. hugs, Brandi

This is not correct. Here is the law. https://www.fmcsa.dot.gov/regulations/cargo-securement/cargo-securement-rules

Quoted are the relevant parts below. It is 1/2 the weight of the load not 1 and 1/2 hence the point of my thread. I don't understand how they deem this adequate.

"The aggregate working load limit of any securement system used to secure an article or group of articles against movement must be at least one-half the weight of the article or group of articles. The aggregate working load limit is the sum of: One-half the working load limit of each tiedown that goes from an anchor point on the vehicle to an attachment point on an article of cargo; and The working load limit for each tiedown that goes from an anchor point on the vehicle, through, over or around the cargo and then attaches to another anchor point on the vehicle."

If the machine/tractor you are tieing down is over 10,000b there are addition rules listed below taken from https://www.fmcsa.dot.gov/regulations/title49/section/393.130


"393.130: What are the rules for securing heavy vehicles, equipment and machinery?

(a) Applicability. The rules in this section apply to the transportation of heavy vehicles, equipment and machinery which operate on wheels or tracks, such as front end loaders, bulldozers, tractors, and power shovels and which individually weigh 4,536 kg (10,000 lb.) or more. Vehicles, equipment and machinery which is lighter than 4,536 kg (10,000 lb.) may also be secured in accordance with the provisions of this section, with ｧ 393.128, or in accordance with the provisions of ｧｧ 393.100 through 393.114.

(b) Preparation of equipment being transported. (1) Accessory equipment, such as hydraulic shovels, must be completely lowered and secured to the vehicle.

(2) Articulated vehicles shall be restrained in a manner that prevents articulation while in transit.

(c) Securement of heavy vehicles, equipment or machinery with crawler tracks or wheels. (1) In addition to the requirements of paragraph (b) of this section, heavy equipment or machinery with crawler tracks or wheels must be restrained against movement in the lateral, forward, rearward, and vertical direction using a minimum of four tiedowns.

(2) Each of the tiedowns must be affixed as close as practicable to the front and rear of the vehicle, or mounting points on the vehicle that have been specifically designed for that purpose."

 

[tcartwri]

The 50% rule is for static loads, and it is a minimum threshold.

There is a primary rule that states that your securement methods must restrain the cargo in a braking situation of 0.8g. Which works out to 80% of the cargo weight. So not only does that supercede the 50% rule, you can see that the sum of the tiedowns restraining forward motion must exceed 80% of the total weight of the machine just by themselves.

 

[bdog]

The 50% rule is for static loads, and it is a minimum threshold.

There is a primary rule that states that your securement methods must restrain the cargo in a braking situation of 0.8g. Which works out to 80% of the cargo weight. So not only does that supercede the 50% rule, you can see that the sum of the tiedowns restraining forward motion must exceed 80% of the total weight of the machine just by themselves.

I read that part on the first link I posted but then in the bottom of that section below where it lists the g forces for various directions it states this:

"Generally, motor carriers are not required to conduct testing of cargo securement systems to determine compliance with the performance requirements. The new rules explicitly state that cargo immobilized or secured in accordance with the general securement rules, or the commodity-specific rules, are considered to meet the performance criteria."

Which leads us back to the chains equaling 1/2 the weight?

 

[tcartwri]

I read that part on the first link I posted but then in the bottom of that section below where it lists the g forces for various directions it states this:

"Generally, motor carriers are not required to conduct testing of cargo securement systems to determine compliance with the performance requirements. The new rules explicitly state that cargo immobilized or secured in accordance with the general securement rules, or the commodity-specific rules, are considered to meet the performance criteria."

Which leads us back to the chains equaling 1/2 the weight?

A little more information now that I'm awake...

The 50% number comes from what is called the AWLL ( Aggregate Working Load Limit )

It is calculated by taking 50% of the rated WLL of each tie down and summing the results. That total number must be greater than 50% of the weight of the equipment.

So for your example of a 20,000 pound tractor using 6600 lb tie downs ( 3/8" G70 chain )

(6600 * .5 ) = 3300

3300 x 4 = 13,200 lbs which is greater than the required minimum of 50%

However to meet the 0.8g rule, you will see that two 6600 lb binders are not enough to restrain forward motion, so at minimum you would have to add one more binder.

And yes, the two rules contradict each other, but you always default to the higher standard.

My source comes from an industry training video that I have from Eager Beaver Trailers. Unfortunately it's trademarked and I can't post it.

 

[tcartwri]

This is a link to the video producer's webstore.

TRANSPORTING CONSTRUCTION EQUIPMENT-DVD