Along with low ground clearance I'd also want independent suspension and disc brakes all around. (
And MAXBRAKE controller). And enclosed undercarriage.
I-S is worth every penny or trouble. Please add an exhaust brake if a diesel.
I see you have an interior height requirement. And one of square footage. Can it brought to a cubic foot requirement instead? While 6'-W is great, 6.6' tall is not. Anything to reduce frontal area is the thought. I'd rather have longer than taller.
The other "requirement", IMO, is a significant side radius where roof and walls meet. Side winds become "trapped" against a squared wall and this is a
safety performance item as radiused curves allow wind to spill over. The longer the trailer, the higher the forces acting from FF/RR while at speed.
Videos of rollovers (big truck and smaller;
and
) reveal this quite well: the
rear of the vehicle lifts first.
The State of Wyoming even has a 2007 White Paper (
"safety study") showing calculations about wind speed versus blowover for various types (a fifth wheel travel trailer is in trouble with about 35-mph crosswinds, a conventional trailer at about 50-mph). As you're running 3k weekly I take it you may have been a truck driver: much of the above is in reference to IH80 near Elk Mountain in winter.
Height is a problem, followed by length, but ameliorated by radiused side walls. The roll center improvement of independent suspension, and radiused walls, is not accounted for in the above study.
Silver Streak Travel Trailers used a 22" radius;
Airstream one that was almost continuous (through the 1970s'). The winds just roll off.
I've scanned around the sites of various builders of enclosed cargo trailers in vain concerning side radius.
On the Pirate 4x4 site are quite a few "builds" using enclosed trailers of the type under discussion for combo living/4-whlr. And, of goosenecks with "campers" installed to also have rear space for a 4WD on the rear. (See "Mobile Marriott" for some great fab skills).
Here's an Airstream-on-gooseneck build that terminated early, but some good stuff shown in re this discussion. See the pics of aero fifth wheels I posted there at end.
As a note, I've generally seen no GN or 5'er where the ground clearance as low as a conventional (with a few exceptions) This a road performance problem. Alternatively, a 10k max trailer one can utilize a
PULLRITE conventional hitch that is functionally
identical to a GN. Aero may be much easier as a result if Q's of ground clearance and pickup bed utilization are paramount. Compare height measurements and calculate COG height on all trailers, IMO.
.