[Big Dave]

Here’s a little AutoCad study I did on travel trailers. I’m assuming a guy who drives around with a trailer at least 20,000 miles a year – enough to make this rig worth the effort.

Length is 34 feet from hitch to tail and its 79.9 inches wide (doesn’t need marker lights and come fair to a standard SRW pickup). In “down” position the top is 64 inches above grade (same as my pickup).

I married the “Hi-Lo” concept with an 80 inch wide Bowlus Road Chief and put a 70 inch long tapered tail on it. The tail reduces wake area by 58%. I gave it a “toy hauler” configuration. The same configuration would work OK as a straight cargo trailer or as a travel trailer.

Like the “Hi-Lo” the trailer comes in two parts: a “tub” that carries the payload and a “shell” top which is raised once the trailer is parked. The “shell includes a flip-up tail cone that tapers in at an 11 degree angle in all aspects. The dimensions of the “tub” dictate that I cannot taper the top until the back of the “tub” is cleared. This assumes full “tub” cargo height all the way back.

Instead of having a cancerous tumor on top of the trailer for HVAC, I would build mine into the nose of the trailer, along with propane cylinders and maybe even a generator.

Why is it so long? Answer: To regain space lost by making the trailer low and narrow. The “tub” (payload) volume is 240 inches long by 76 inches width (interior dimension) by 54” high. That comes out to 985,000 cubic inches. Your average “Wheaties Box On Wheels” is 104 inches wide by 80 inches high (interior dimension above load deck). So the load volume of my aero trailer is roughly the same as a 10 foot long standard trailer. At best, Spartan accommodations for two. The triple axle is probably not necessary unless you carry Die-Hard batteries for cargo.

I also did a 108 inch wide by 80 inch high version that makes a fairly good car hauler.

Is it aerodynamically superior to the average box on wheels? Of course. How much? I don’t know. A wind tunnel would be necessary to determine that, but I’d say it had better beat the box on wheels pretty bad to justify parking a 34 foot trailer.

BTW, sorry about the shabby picture of an AutoCad drawing. I an not much of a hand at sharing data files (I’d rather think about cars) and AutoCad (as I know it) wants no part of Ecomodder, so I simply took a picture to help everyone visualize what I’m talking about.


On edit.
Forget the attachment. The durn thing just will not co-operate. If anybody cares, send me a PM and I'll send you a 1.35 Mb picture or a .dwg file if you want it.