They are very strong and can be used as regular shelves or as stock racks.
You can even use them for workbenches if you put them at the right height.
The uprights are "unistrut" u-channel that hang from the container's upper tiedown rings.
The shelf support brackets are as simple as possible, just a flat plate or board with two holes in one end.
They bolt onto "springnuts" a.k.a. "diamond nuts" inserted in the unistrut.
Here's how to get the wood for your shelves very cheap.
In this photo Michael Kearney puts freshly linseeded boards up.
The brackets must be bolted firmly. When the wood dries and shrinks the bolts must be tightened again. Otherwise these shelves are a deadly time-bomb booby trap.
Step 1: Shelves of Death
After about a year they tended to sag a little bit. The bolts gripping the brackets slipped a bit because the wood shrank. I didn't think much of it.
Then the end-grain wood failed and the brackets collapsed, dumping everything into the middle of the container. Damn. I'm glad I wasn't standing under that stuff.
So then I went around tightening the bolts on the remaining brackets. It would be good to add some kind of a cheek plate to the brackets so they couldn't fail in this way.
Check out this collection of other dumb mistakes I've made.
Step 2: Brackets
We bandsawed these from ash wood and drilled the holes with a drill press.
We rested the board on a piece of scrapwood to minimize the "exit wound" from drilling.
Moana applies linseed oil to the brackets.
Step 3: Bracket Version 2
That's to keep the shelf boards from sliding off in an earthquake.
We waterjet cut a whole lot of these in different lengths.
Step 4: Uprights
Michael shapes the top end with an air wheel.
The upright hangs from the container's upper tiedown ring by a u-bolt.
The u-bolt goes through the two holes revealed by the cutout Michael is making.
We scribed, centerpunched, and then drilled the holes on a drillpress.
Stuff tends to get stacked against container walls up to about waist height, so you can saw off the bottom half of your upright and not lose much use.
We used the square channel, but the flat channel would probably work too.
Step 5: Boards Boards Boards
Then we brushed them with linseed oil and set them in the shade. If you leave them in the sun it will set too quick and you'll get "orangepeel" on the surface.
Cherry is overkill, but I got a deal on a couple of bundles of "rustic" cherry. A customer had returned them for being too rustic (spits, knots, and rotted spots).
I ask the lumberman what he's tired of having. He's happy to forklift all his infested wood and returns on my truck's lumber rack and bottom my springs out for a couple of twenties. He's a good businessman and maximizes inventory turns. He wants me gone quickly cuz his partners slept through that class.
Step 6: Diamond Nuts A.k.a. Spring Nuts
The ones with the plastic retaining wings are the easiest to use.
We ran out so we water-jetted a bunch and tapped (cut threads) them with a "two-flute gun tap" which is a type of tap that pushes the chips down into the hole. You can use it in a power drill without breaking it.
Then we put up the uprights, brackets, and shelves. At the back of the container we put boards all the way across the container and rested them on the side shelves. That made a deep shelf at the back for large objects.