Do all chains count for the WLL to prevent 80% forward force on coils?

Downward force counts too. Remember - "must be strong enough to withstand forces described..." If a chain pulling down can hold 80% of the load going forward, then it counts. If it's suicide, it's going to have to get past the front dunnage, and downward force also keeps that from happening.

But since we're on the subject, I've also always had a question about coils. Take suicide as an example. The closer you get to the bottom of the load, the more leverage the top part of the load has on the chains. So if you have a legit 45k of securement on the top of a load, but now you move it to the middle, you now have leverage against the chains. So if it's directly in the middle, would you lose some percentage? Now picture running chains directly through the bottom of the coil (just pretend for a minute) Think about how much chain you'd need to stop it rolling in a crash when you've got 45k in weight above the chains.

I know I'm doing a terrible job explaining it, but it's about the load increasing it's mechanical advantage against your securement. Like a force multiplier.

 

All you can do is keep the coil in the bunk. If it moves at all it could leave the truck. Half the weight of the coil in working load will hold it in the bunk, and drive the friction factor up to where the coil won’t move. Friction holds it on there, but all the chain in the world won’t if it moves, even in a 1/4”a big coil generates enough kinetic energy to part 3/8” chain and leave. Big coils loaded suicide I can get 5 chains on even with steel corner protectors, more if you’re using cuffs, and keep them tied off between the coil blocks in the bunk. You need to pull down on the coil to increase the friction factor. The shorter you keep your chains the better. The more length of chain you have stretched out and the angle decreases the amount of effort you’re actually putting on the coil. Once you’re tied off outside of the blocks in the bunk the effort you’re putting on the coil drops fast the farther away you get. A chain through the eye tied off 5’ behind the coil may look right, but that chain is literally doing nothing toward keeping that coil where you put it. The load security devices driving the friction of the piece on the deck up is what holds it on there, not specifically the WLL of the chains relative to the weight of the piece. Think about anti-tank guns. If you take a 6 pound chunk of iron and accelerate it enough it has enough energy in it to go through 7” of armour plate 2000yds away. That’s the same physics you’re trying to head off with the chains. You can only stop it from moving, if it moves at all it can build more theoretical weight in kinetic energy than you have in all the WLL worth of chain on the truck let alone on the coil.

 

First things first, the cargo securement handbook is not law. There is some contradicting information in that versus the actual regulations which govern
our industry.

You always have to read the entire regulation, you can’t just pull bits and pieces out of it.


§ 393.102 What are the minimum performance criteria for cargo securement devices and systems?
(a) Performance criteria -

(1) Breaking strength. Tiedown assemblies (including chains, wire rope, steel strapping, synthetic webbing, and cordage) and other attachment or fastening devices used to secure articles of cargo to, or in, commercial motor vehicles must be designed, installed, and maintained to ensure that the maximum forces acting on the devices or systems do not exceed the manufacturer's breaking strength rating under the following conditions, applied separately:

(i) 0.8 g deceleration in the forward direction;

(ii) 0.5 g acceleration in the rearward direction; and

(iii) 0.5 g acceleration in a lateral direction.

(2) Working Load limit. Tiedown assemblies (including chains, wire rope, steel strapping, synthetic webbing, and cordage) and other attachment or fastening devices used to secure articles of cargo to, or in, commercial motor vehicles must be designed, installed, and maintained to ensure that the forces acting on the devices or systems do not exceed the working load limit for the devices under the following conditions, applied separately:

(i) 0.435 g deceleration in the forward direction;

(ii) 0.5 g acceleration in the rearward direction; and

(iii) 0.25 g acceleration in a lateral direction.

(b) Performance criteria for devices to prevent vertical movement of loads that are not contained within the structure of the vehicle. Securement systems must provide a downward force equivalent to at least 20 percent of the weight of the article of cargo if the article is not fully contained within the structure of the vehicle. If the article is fully contained within the structure of the vehicle, it may be secured in accordance with § 393.106(b).

(c) Equivalent means of securement. The means of securing articles of cargo are considered to meet the performance requirements of this section if the cargo is:

(1) Immobilized, such so that it cannot shift or tip to the extent that the vehicle's stability or maneuverability is adversely affected; or

(2) Transported in a sided vehicle that has walls of adequate strength, such that each article of cargo within the vehicle is in contact with, or sufficiently close to a wall or other articles, so that it cannot shift or tip to the extent that the vehicle's stability or maneuverability is adversely affected; or

(3) Secured in accordance with the applicable requirements of §§ 393.104 through 393.136.

The above bold section, 393.104 through 393.136 is the general securement regulations, and cargo specific securement regulation. Those are what you have to follow, to legally secure a load in the United States.

393.120 has the regulations for securing coiled metal.

 

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They’re using a lot of words and formulas to say a chain tied off inside the blocks of the bunk pulls the coil into it while a chain tied off outside the blocks is trying to pull it out. Friction is what you’re after, so looking at the piece figure out where you can pull from and to to increase that. Formulas and angles and working load of devices just complicates things that are pretty simple. Keep your chains as short as possible between the contact point on the coil and where you tie off to and you’ll generally find your chains land somewhere inside the blocks of the coil bunk, as long as you stay in there you’ll be inside their formulas and foolishness too. Just a suggestion. If you spent $1.50 and a half hour on a cup of coffee with an old steel hauler, you’d be putting yourself farther ahead than with weeks of driving yourself nuts with regulations written in legalese and the suit and skirt produced handbooks that go with them.

 

This is what's called reading into the regulation. As kylefitzy has pointed out, you can't read regulations in isolation (bits and pieces), and if you read them, you'll always see a re-reference to prior or other subsections that also apply, and this is what drives normally sane people crazy, but those of us that are already crazy see their madness for what it is. People like specifics. So this particular aspect gives you some specifics pertaining to this particular item, but all the other rules also apply.

You can't read regulations like a book, from beginning to end, unless you're ready to read it all and also go back to all the previously read sections, to see that they also apply to this section...so in essence what it is saying, is that you need to have at least one tiedown through the eye of the coil to restrain against forward motion. And backward motion, but the total amount of securment of these chains must still also meet the aggregate WLL, so yes you will have to have more chains...and yes they must (now pay attention to the exact wording) If possible, the angle between the tiedown and the deck should be less than 45°. This says if at all possible, keep the angles under 45 degrees, but if unable, you may exceed that angle but as little as possible. Now all trailers are not designed the same, even though some standards exist, and there is no requirement to have a certain amount of anchor points within a certain spot that a coil in suicide may be loaded, so you have to align with the regulations as close as possible.

Remember, in legal documents, if it does not say must or shall it should be followed as close as possible. If however, it does say must or shall, there is no option or interpretation to be otherwise assumed. It must be as written. When you see these regulations and they say,

An individual coil. Each coil must be secured by the following: means it must be secured in the conditions that follow, and one of those conditions is if possible the angle between the tiedown and the deck should be less than 45 degrees. What this means to you and I, is that at a minimum, there will be two chains, one preventing forward movement, one preventing backward movement, and those chains should be 45 degrees or less to the deck if possible. That's minimum...then the other sections of regulations come into play regarding Aggregate WLL requirements, meaning more chains and/or straps.

It's like flatbeding or anything else, once you learn how to do or read it, it gets easier.