I don't have many good pictures, but I can describe how mine are built. The vertical legs on the aisle side are toe-screwed into the floor. They are also attached to the walls, but that's more to stiffen the walls than the beds. On the wall side they are anchored to the seat rail. It is really solid! There are crossbraces everywhere between members. I think every node has atleast 3 members connecting to it. The most important thing we found was to have things interlock. Notching the wood is a pain, but it makes everything stronger. Also, there are 5 total crossmembers under the bunks to give them some strength. The plywood really just keeps the mattresses sitting nice and level, but doesn't do much to actually support the weight.
Like I said...I didn't take many pictures, but scattered throughout this album you might find something of use to you.