In preparation for an 1,100 mile road trip towing my 5x10 utility trailer I mainly wanted to protect a nice antique from possible rain and snow. A tarp can work if done well or it could be shredded by the wind in a matter of minutes by sustained 55 mph wind.
My solution? Enclose the trailer. But it's not worth high investment in a long term solution. Once the trailer arrives at its destination the enclosure is no longer needed. Nor wanted frankly. So whatever I build need only last that one trip. A one off. So it's not worth spending much money on this project either. Fortunately, I had a lot of scrap material from a remodeling project. Almost enough. Almost.
So the goals included using what I had, spending as little money as possible, and protecting the cargo. Oh yeah: why not reduce aerodynamic drag while I'm at it? This was the concept.
Sorry these pix are not very good. It was dark when we went for a test pull. The flash didn't help enough. Better pix are planned (later). For now, here he is hitched up to Dr. Tundra for an idea of scale.
This shot shows the curved rear sides.
Why different colors? Frank was built from spare parts. Monsters can't be picky.
One more shot to give an idea of front curvature.
Rounding the top edge was an advanced move for grins. Hopefully letting some air on top will help with attached flow.
Here's a daylight rest stop shot taken Saturday, Mar 6.
From this view I think all the major design elements can be seen.
This was my criteria for success.
I was satisfied on all counts. Frank was very well behaved. Zephyr gave some resistance: maybe 10 mph. Our trip average was 15.7 mpg. That was right in line with my expectations: same truck, same trip, two other trailers (Scamp 16' & 19' models).
They say beauty is skin deep; ugly goes all the way to the bone. Frank knew a pagent was never in his future. That's okay. He was born to serve and protect. He was also made on the cheap: built almost entirely from scraps. The only materials purchased were two sheets of masonite pegboard (upper rear panels) plus a few hundred screws. And those are being reycycled! So the net cost was not money just time.
Here are some pix taken during construction. I started with the lower rear curved sections. The final angle was 15 degrees on each side with 6.5" inset over 48" curvelinear length.
The lower section was extended to the front of the trailer. The deck was 61.5" wide so the nose radius was half that (30.75"). The lower section was 22.5" high and truncated at the front of the deck at 48" width and 39-deg angle. So 102 degrees of nose curvature (a bit over half) overhung the front of the trailer.
The upper section added 48" more height. The nose piece was scalloped to allow some direct airflow onto the flat roof. From side view the top edge was turned down to a 45 degree angle. So the chamfered anchors were cut 45, 30 and 15 degrees from center outwards each way. The backing scraps provided reinforcement to avoid the anchors from just splitting out. In addition to those screw points, nylon zip ties were added every couple inches to help secure the top two peices together. I would not trust this construction to prolonged use, and it was not weather tight either, but for the one trip it worked just fine.
From there back the upper sides and top were simpler, being mostly straight. Splints were used the bridge the joints where top and bottom panels met.
