TRAILER SHAPE

[Capebuild]

Good Morning....We would like to somehow incorporate a toilet (https://natureshead.net/) into our trailer. I was thinking if the galley were half the trailer's width, I could bump out the trailer's cabin into the galley's other half and create a small toilet space. However, the way the teardrop profile tapers down toward the galley, that taper limits the room for "sitting" in the toilet space. I then thought about reversing the profile, having the profile's taller end at the rear (I'd like to stay away from the boxy shape of a Benroy). I've been looking at the Vistabule trailer and that seems to have a pleasing profile with a reverse teardrop shape (see attached). So, my question is, does anyone have any thoughts about how a reverse teardrop travels. Does it put more stress on the tow vehicle, aerodynamics and all? Any other thoughts "about this plan" would be appreciated.

Thank you.

John

[Juneaudave]

A toilet inside a traditional sized teardrop is like the holy grail of design, many seek it but few find it. You might give further thought about making a storage area for a portable toilet and a nice dressing/shower/privacy tent. We have found that most the time, we can stop at a gas station or something while on the road, and once at camp, its pretty easy to set up a shower tent to keep a toilet in and get dressed and/or clean up in.

[saltydawg]

Or add a basement, with the toilet sitting in the basement.

[Capebuild]

Thank you both for your replies. I do appreciate your thoughts about installing a toilet (or at least considering that feature)
I was more interested in getting other's thoughts on how a reverse teardrop shape might drive on the road being pulled by my Subaru.
Would there be a big difference in the aerodynamics? (guess I put a little too much emphasis on the toilet in my original post :-)

Thank you!!

John

[tony.latham]

...other's thoughts on how a reverse teardrop shape might drive on the road...

I don't have the answer. But keep in mind that an airfoil creates lift on the upper surface and the Vistabule looks like an airfoil. I can't believe it creates much if any downward pressure. Speculation on my part.

There may be a Vistabule forum group you could query about tongue weight/pressure while towing.

Also of note –-and I don't know if this will help-- but Camp-In says their Raindrop gets better mileage than their teardrop-shaped camper.

Tony

[halfdome, Danny]

Our first teardrop my wife wanted some sort of bathroom so we bought a porta potty and a Cabellas shower tent to take care of the problem. To this date neither have been used, we use the facilities nearby.
Danny

[Juneaudave]

Here is a thread on airflow FWIW. http://www.tnttt.com/viewtopic.php?f=27&t=68650&p=1207013&hilit=teardrop+airflow#p1207013

[Capebuild]

Thank you all for your thoughts, once more. And good idea to check if there's a Vistabule forum, Tony.

That post you referred, Juneaudave, looks pretty interesting. I just took a quick look at it... but will spend more time absorbing it later.
But that is a good idea to just do a bit of research on aerodynamics.

Not to get too sidetracked from designing the trailer...as one can easily get lost down the rabbit hole.

[troubleScottie]

There are many articles here on drag or the effect of shape. Search for "drag".

Many factors to consider. A lot depends on the tow vehicle and the relative shape and size of the trailer. The same design when towed by a truck versus a Prius will have big consequences. In following the site for years, there has been no comprehensive attempt to measure or quantify performance of any teardrop design/shape/manufacturer with various tow vehicles. People appear to either live with a design's deficiencies or build a new one.

A reverse TD design changes your half wing into a wedge. Most likely increasing the drag. Is that significant? I do not know.

In general, the optimum design is a half wing whose front cross sectional area is in the shadow of the tow vehicle. All other variations will have more drag. Increased drag will affect gas mileage, etc. The other factor is the mass of the trailer. Again, less is better. Then, the next question becomes what can you live with (or without).

[Tom&Shelly]

In following the site for years, there has been no comprehensive attempt to measure or quantify performance of any teardrop design/shape/manufacturer with various tow vehicles.

It's an interesting idea. Aerodynamic testing would literally take a supercomputer, or wind tunnel tests with accurately built models, or experimental tests with the real thing. The first two, of course, exceed the research budgets of most teardrop builders.

Most of us can afford one, or perhaps a few, research subjects. For those who have measured, it would be interesting to post tow and non-tow vehicle mileages, along with the TV and camper size shape and weight. (They are, in some cases posted in other areas of the forum, but not in one place.)

I'll post ours, when we are in a position to collect data later this Spring.

Tom

[Capebuild]

I've been doing a bit of research off and on during the day about all this. In the planning stages, and not having built a trailer before, I want to explore all the angles; sort of speak. I'm not sure the idea of putting a toilet in the trailer is all that realistic, but I need to explore all the possibilities. I've seen one on a you-tube video. Kind of an interesting way the guy did it. But the more I think about it, my wife and I would be crawling around on our hands and knees to get to the toilet. Doable, but that might get old soon enough. But that is what got me thinking about putting the larger round of the teardrop shape in the rear of the trailer and somehow configuring a toilet in that enlarged area.... thus the drag-aerodynamic issues and concerns. Others suggest the issues could be a compromise on gas milage or more wear and tear on one's tow vehicle.... I was more concerned, I suppose, on the trailer becoming unwieldy to drive at highway speeds. and still others say the drag would be minimal to not an issue at all. I'll keep thinking about it, but maybe one of those outside toilet tents and some sort of toilet unit will do.... and I can go back to my original design thoughts of traditional streamlined teardrop shape.

Thanks again for the help.

John

[gudmund]

here's a shot of my tow vehicle with a Benroy shaped trailer - the air spoiler you see mounted on the rear of the canopy/topper has given a 1.3 mpg overall increase so far after over 10,000+ miles so far. The almost $300 I spent making it along with the mounting parts - I figure will be paying for it-self after about 20000miles more miles of towing, My overall mpg average had been just a-shade over 16 mpg before it's mounting and now after all of my trips combined mpg since, it has been over 17.4+mpg overall since. And of course, it's the long steady runs that have given the 'big noticeable' mpg increases, with the short "stop & go" runs showing no difference. The trailer sits 4 inches higher (69inches) than the top of the PU (65inches) The trailer w/tongue weighs in at 1650lbs loaded - fully loaded truck & trailer 'all' weights in at 6500Lbs. The PU is the 'base' '12 GMC Canyon 2.9L 4cyl w/auto trans & 3.73 rear gear. Hope it won't be causing too much of a change in future mpg - BUT - I am adding a roof rack on the trailer for the mounting of a 270'de' side awning on the pass side. It will be adding about 75lbs to the trailer with the take away of about the same amount from the PU bed, being I will not be carrying the 2 easy-up's any longer......................

[Socal Tom]

Have you seen the cabin car design? That design has a small "bathroom" at the front, and the bed is toward the back. I've had a general concept that plays with that idea. If you want to stay at 5 ft wide, and you go 10 or 10.5ft long, you could take the front 2 feet and make a small " entry way, with a door on left side and the right side would have a small cabinet to hold a portapotty ( you could even make a outer door for clean up if desired). Put a bulk head between the entry area and the bed, with a curtain. The down side is you have to climb over each other to get in and out. However, if you add a 2nd door on the right side, at the bed, like a traditional TD you could get around that. The entry way also gives you someplace to put on shoes, or jackets and store chairs and what not for traveling.

another thought- If you put both doors at the bed, and just have a gap in the bulk head in the middle then either of you could get in the bathroom area if needed, but it sort of kills the idea of using it for storage unless you add a third door.

concept sketch

[Shadow Catcher]

Not the most aerodynamic but we will sacrifice a few MPG for comfort.

[drhill]

Looking for space in the front of the trailer reminded me of an old design with a bike garage at the front. I did a search and found it again. Have a look at this thread and it might give you some ideas.

http://tnttt.com/viewtopic.php?f=27&t=55299&start=30