What would you have done differently??

[Hammerhead]

Now on a load like themissinglink's the chains are stronger than the frame holding the conveyor belt, so it distorts the frame, which is why they don't stay tight. These loads are a royal PITA, because the frame actually isn't strong enough to support proper securement.

Yes the regulations apply to us, just the same as they do to everyone. However, we specialized guys get some leeway because sometimes there just is no way to actually hit the numbers, it's just the way it is. It's also a bit of a code of respect, because most of us know a thing or three...

X-chains, or cross chains as we call them are WAY stronger than the way you're talking Chamberpains. There's several things to think about here, first off a crossed chain is pulling "through" the trailer. By that I mean it is literally pulling from the outside of the trailer, through the crossmembers and into the actual frame of the trailer, not just the outer portion if it wasn't crossed. The structure is stronger this way, and you get less deflection of material. Something that doesn't matter with general freight, but when you get big and heavy the world changes and physics works.
The other part to cross chaining everything is the chain performs two or three functions of securement instead of one or two. It pulls to the side, it pulls back (or front), and it pulls down. It does all of these in the effective angles to get maximum tension and resistance per tie down, thus doing more with less so to speak.
When a chain is pulling straight back it is effectively useless. Yeah, I know everyone will argue this, I don't care. If you believe different you don't understand and I can't help you. A straight pull chain has 100% of the force applied to it, so at Max it's only option is to fail. A crossed chain that also pulls back is not pulling at 100% dead straight, but is also dispersing some of that stress through the elasticity of the material, and therefore has a higher failure threshold. Look at the markings on crane rigging, straight is always the weakest...ain't rocket surgery.
Another reason for cross chaining is stress dispersal. When you look at a lattice boom crane, are all the supports vertical and horizontal? No. They are angled to maximize the stress dispersal into a larger area, thus again doing more with less.
Cross chaining also brings opposing forces into play. When a load is cross chained and starts to lean, the forces are opposing instead of on the same side as the lean, this helps "bring the load back" to the other side of the trailer and increases stability.
Once you begin to cross chain larger items and feel the difference, you'll never go back to not doing it. Some people never learn, and you can't fix stupid, but when you play with big freight, you'd best be prepared to become an abstract thinker if you want to do it effectively. Look around, see how other things are done, ask yourself why and try and figure it out, then see if it's something that can translate into what you're doing...there's a reason I'm not scared to out 122000lbs of 15foot wide by 15foot high bucket on 44inches of rail/beam and move it from southern Arizona to northern Alberta...I know and understand the forces at ay, and not only work within them, but I also know how to exploit them as well.