Were I to build this myself, it would necessarily come after the full Coanda-effect kit on my panel van and turning my '58 Beetle into a redwood Zeppelin. So I release this under Creative Commons Attribution 3.0 Unported* for anyone who wants to build a teardrop, but doesn't know how to get outside the 'box'.
What defines a teardrop? I would suggest
•simple-curved aerodynamic shape
•one-sheet floor
•no standing room
•side hatch entry
•body narrower than the wheels
•rear kitchen
What I propose
•simple-curved approximation of The Template
•since I'm cutting the sheet, I cheat with a 4x12 or 5x10 sheet
•I propose to stretch the template in the Yth direction — 150 to 200%
•move the entry to the truncated boattail
•tandem wheels on a single axle
•5 out of 6 ain't bad, integrated water storage
I've worked with geodesic domes so I'm used to approximating curves with straight lines. The template could be rendered as a low frequency triangular faceted asymmetrical dome, as I did with the
wooden motorhome design. In this case I start with a hexagon base and curved vertical edges. The 60° angles become 45° in front to accommodate jack-knifing and 22.5° in the rear to give a good closing angle. The tail is truncated to the size of the door. The various possible [straight or] curved edges mean the shape goes all wiggly-wobbly compared to a geodesic shape. Straight edges result in a Template semicircular arc, a 5' wide body would have 2 1/2' of headroom. A deep curve would result in a Conestoga-like wide body.
One thing I once owned that went down the road to an hopeful new owner was a 1952 Silver Streak Clipper. I don't have the trailer today, but I do have a measured drawing.
The quarter-spherical end caps use tightly gored material, narrow strips in simple curves and lots of seams. The thing I like about the construction of that trailer was that the frame was a 5" diameter center spine with 6" C-channel crossmembers. And that was it—each crossmember terminated in a carriage bolt through the plywood deck An aluminum C-channel the same thickness as the skin material was screwed to the upper surface of the deck to carry the inner and outer wall skins. The outer skin was aluminum and the inner was steel.
A second influence is the Bowlus Papoose. I saw a 20-footer when I was in college, and they sell 35-foot Bowlus Road Chief replicas for $100,000 (or try to). The Papoose is 16 feet long, that's getting into teardrop territory. It's one of those cases where it would go faster backward.
Another influence is these pictures I found of a trailer called The Roswell.
What this suggests to me is to use the hexagonal-pod construction (a design that goes back at least to Domebook 1, if your interested) to get a low-resolution highly-streamlined shape that because it uses the simple curves and has one flat wall is IMHO technically a teardrop!
So using the construction of the Silverstreak frame and extrapolating from the single-trailing-arm suspension on my Westphalia utility trailer, this design extends the Roswell concept in three ways:
•The door and it's associated framing is moved from the thin-walled side, to a flat truncation of the Template shape.
•The Stretched hexagon plan of the Roswell is made asymmetrical. The front angle is 90° to allow jack-knifing, and the rear angle is 45° to get the 22 1/2° optimum taper in the rear. The profile is level from the center [skylight] to the top of the door.
•The suspension consists of a dog-bone arm (sort of like a double-ended front motorcycle fork) that pivots on an axle stub and carries a wheel and tire on each side. The design scales from a 4x8 on 4ea 8" wheels to a 5x10 on 10" wheels or even a 5x16 on 12" wheels.
Small versions might be unsprung. More advanced version would have rubber in torsion and disk brakes or kinetic recovery that dampens the ride by charging a battery.
The center tube could double as a water tank, with the weight carried low in the center. 3 to 14 gallons by my calculation. The back of the Buck-Rogers-fin-like flat Trophenwagen-style fender top would flip out into a seat on either side of the door or a bench along the side. The rear bumper folds down into a step beneath the door. Kitchen (if any) would be over the hitch, the reverse of normal teardrop practice.
Cross section could be anything from the 5x2.5 aerodynamic optimum to 4x4 or as big as 5x6, and it could be squircular! I think once you widen the body and enclose the wheels it's not really a teardrop, although 4/5x6 would look something like an horse trailer. If the wheels were at the center section, half wheelwells could fit in pretty neatly, making shelves in the interior.
This leaves a lot unsaid, construction materials (PolyMetal vs corrugated vs burlap/hoops), center of balance, central skylight bubble vs trolley roof, & etc,. & etc. I choose to stop here.
'What do you think, Sirs?'
*This work is licensed under a Creative Commons Attribution 3.0 Unported License.
Creative Commons — Attribution 3.0 Unported — CC BY 3.0