I made my 7 ft x 30 in bunks collapsible so they would double as benches while in travel. Attached is a pic of what one looks assembled and collapsed. I made them mainly out of 2x4s with 2x6s incorporated in the top bunk frame on the ends and in the width of the middle to keep them from shifting with in route. The uprights are 4x4s and they are bolted to the frame of the top and bottom bunk. The platforms are 3/4 plywood and rest on ripped 2x4s that are recessed 3/4 inch below the outside frame so when the platforms sit down inside they are flush with the frame. All of the uprights and bottom platform boards fit down inside the bottom bunks while in travel. I put carpet inside the bottom bunk to help with any board rattle while in travel. I also installed some sticky back weather stripping on the bottom bunk frame under the platform boards to stop any board rattle while the bunks are assembled while going down the road.
I can set up both of them in about 25-30 minutes with one person. Although they are a little heavy for one individual, but manageable. Itís a Ragbrai Bus so I didnít want them permanently stationary b/c Iím traveling with several people and need the seating. A friend gave me a twin size 100% foam mattress 4-5 inches thick. I filleted it with an electric knife and cut it for width.
Am I happy with them? Yes. My only issue with this design was I had to incorporate a work around solution to getting the bolts out of the 4x4s. They are 6 inch carriage bolts and I had to make sure I left room to pull them out of the frame. Something I didnít think about completely until they were inside the bus Ė you know how that goes.