M105, Deuce & CCKW are carrying vehicles.
Load: A mule is fine. Attached is a frame from a video of the mule parked in the middle. Elsewhere on the clip is the driver jumping up and down on the ramp beside it. We think we could do a Jeep with a single reinforcement pylon in the middle of each side. Might give that a try this summer.
Weight: Don't know the assembled weight but 1 guy can handle it because everything comes apart. When assembled, one guy can shift it a few inches in any direction or drop it down. Heaviest piece is one of the 2 x 10 x 13s.
I wouldn't use standard Home Depot wood for these loads in these dimensions because the spruce has the give.
Note the straps attached to eyebolts on the top 2 x 4 and vehicle frame. Keeps it from kicking out.
2 x 4s are kept from falling off the bottom by 1/4 x 20 carriage bolts & wing nuts.these spread the weight across all 4 boards and keep them from moving apart.
Assembly is about 12 - 15 mins with 2 guys who have the rhythm down. Cost: Under $150.
Now that we've made these, I think the design could be improved for faster setup/teardown by tweaking the cross boards or replacing them with steel so they drop in from on top, but . . .