I looked through forums, considered geometric principles for strength, and contemplated how I could make something that would work for me and the Mrs. The first thing I ruled out was the idea of a 4 foot wide option. I started out by ordering the 5 x 8 foot trailer from Northern Tool and continued to examine ergonomics and efficiency. I made the profile based on a simple geometry of a 48″ radius curve for the rear section and a 30 inch radius for the front. When plywood is formed into an arch it becomes incredibly rigid and the dimensions I chose put the front 30 inch radius curve where the trailer will be outside the slipstream of the car. The lower 18 inches will be inside the slipstream and not breaking wind. The 30 inch radius will also maximize internal headroom. Ergonomic placement of the door allows you to sit in the door and pivot to lay down without scooting up or down. The axle is moved back slightly to accommodate room for a fender that will not interfere with the door. With the axle moved back trailer stability will still be good because the box for the 22 gallon water tank (emptied when driving), pump and battery and other galley weight will provide relief to the tongue weight.
Looking at galley door pictures on the internet, cutting the ribs out of plywood just didn’t seem to look tidy and professional. I decided that I would make all curved framing and structural supports by laminating thin strips and building them on a series of jigs. These items would include the door frames, window framing and galley door spars/ribs. Since laminations hold their position well and have great strength they will be run top to bottom. 5 of these spars should provide plenty of strength to hold the 1/4 inch plywood without deforming the curve.
Another design choice was to make 2 side doors with a forward hinge so that my wife and I can both get in and out without a hassle and if a door should open while in transit the wind will keep it closed not tear it off. I have seen a number of trailers with doors that open toward the rear and never understood that.