I have narrowed it down to a step deck but have a few questions

It wont "rip out" what will happen with a lot of weight is that it will sag, making the doors come open, which will eventually lead to either the hinges failing or the front bottom of the box bending or cracking. In the meantime, i would keep the weight as far towards the box ends as possible.

If you have coil racks, place them down and then the heavy stuff on top of them

 

This is what happened to my box after about a year and a half of use. But I had something like 20 chains riding in that thing, plus all my straps. Way too much weight. I was storing the chains in two 8 gallon stainless steel trash cans, which did a nice job of containing them but centered all the weight on one area. Oops. I can see how the method described by skallagrime would at least take the weight and spread it out evenly.

 

.

 

@Dadetrucking305

here is a setup I saw today once you get ramps (if you do) I like that dunnage rack. He has one on both sides.

 

Yep, if you note, the face of the box is bowed down causing door issues as well, id wager that happened long before the break happened, gotta keep the weight towards the back of the box where the back can act as a full height gusset too

 

If I’m spending someone else’s money this would be a great setup. His boxes are much taller then yours though. I’ve also seen guys take rectangle square tube to make pockets for each chain.

I used 4” pvc drainage pipe for my chains in my headache rack. Works great with my ratchet binders stored above on a rack.

 

Here's my experiences trying to use a box like you pictured.
1- The chains are NOT going to stay in the rubber tubs. They're going to bounce around and move to whatever location they want to be in and then they're going to keep bouncing until your box breaks. Every time you go to use them, you'll try to figure out why 2 chains are in 1 tub, and who the heck tied them in knots.
2- The binders are going to make their mission to hook to the chains that are bouncing around. They'll successfully find a place to secure to your door latches to other heavy objects, making opening your box next to impossible. That is, unless they decide to just break your latches and kick all your stuff out while going through a construction zone with jersey barriers on both sides. (Not me, but a co-worker)

I only carry 2 things in my trailer boxes now. Pipe stakes and tarps, and I'm still looking for a better place to put the pipe stakes...

 

Dang, that is a beautiful setup. Some money went into that! I actually had envisioned something similar with welding some flatbar across the top to hang my chains from. The weight of the chains would obviously still be riding on the bottom of the box, but that would keep them in place and make them easy to retrieve. But, the weld shop wanted something like $1100-$1200 to fabricate that and my boss said no way (Obviously, I am not a welder, perhaps I should learn).

 

Take some 3/8x 2 or 3” flat bar and a few 3” long pieces of 1” square tube. Use the square tube as spacers between the flatbar and the box. Using 1/2 grade 5 o