I agree, Jim911. They are the best! There was another fellow 10 years ago who made similar boxes from brown cardboard, but you could not fill them with locomotives - they were just too heavy. Doug has the right idea. One level of locomotives is enough by itself. Two levels of cars are easy to pick up.
I gently remove the side foam before removing a locomotive; when placing it in a Hauler, I remove the side foam and position the engine, then carefully slide the foam in. Nothing has bent or broken, using this technique
I have a small hand truck that can be oriented as a vertical truck or as a small flatbed. It allows moving multiple haulers in and out of club layouts.