I bought a stuck Lister diesel genset years ago (it's still stuck) on a single axle trailer with a fuel tank. I'm thinking about re-purposing the trailer just for fuel. I wonder about a single axle and the center of balance?
10 percent should be on the tongue as a good rule of thumb. So find the center of gravity and move it forward to get the 10 percent. \I bought a stuck Lister diesel genset years ago (it's still stuck) on a single axle trailer with a fuel tank. I'm thinking about re-purposing the trailer just for fuel. I wonder about a single axle and the center of balance?
You can have multiple separate tanks as long as none of them have more than 119 gal individually. and the total is under 1000 gals total if I recall correctly.
-I don't have the math skills for COG in the part of my brain I use daily so I usually cheat by using software. Finding COG can be done with several 3D CAD programs once everything has been modeled, which shouldn't take very long to accomplish if you have all the dimensions. Just a suggestion if the OP doesn't want to do the math.10 percent should be on the tongue as a good rule of thumb. So find the center of gravity and move it forward to get the 10 percent.
The problem is the OP's question doesn't have a single answer. It depends on the tank configuration and the loading. For a single full tank it is pretty trivial to calc. Actually it is fairly trivial for any loading condition until you start talking about sloshing. For three tanks partially loaded, it is actually still pretty trivial to do the math, but you are going to get very different answers depending on the exact dimensions.-I don't have the math skills for COG in the part of my brain I use daily so I usually cheat by using software. Finding COG can be done with several 3D CAD programs once everything has been modeled, which shouldn't take very long to accomplish if you have all the dimensions. Just a suggestion if the OP doesn't want to do the math.
How big is this tank? Those Listers are real fuel sippers so I'm guessing that the tank might be smaller. Sorry if I interrupted your question as using the existing tank.I bought a stuck Lister diesel genset years ago (it's still stuck) on a single axle trailer with a fuel tank. I'm thinking about re-purposing the trailer just for fuel. I wonder about a single axle and the center of balance?
I have used fusion 360 to do the same.-I don't have the math skills for COG in the part of my brain I use daily so I usually cheat by using software. Finding COG can be done with several 3D CAD programs once everything has been modeled, which shouldn't take very long to accomplish if you have all the dimensions. Just a suggestion if the OP doesn't want to do the math.
All of the manufactured mulit tank non hazmat fuel trailers have cells that are approx. 30" cubed. Sloshing is non existent with them. I haven't seen/driven a tank truck yet that has that much baffling.This gets fun when you consider the potential weights involved. A 3/4 ton truck can support a full 120 gallon tank in tounge weight alone, assuming 7 lbs/gal diesel.
Thus if you only have one tank, it literally doesn't matter. If you have multiple, it starts to get fun. If you have 3 120 gallon tanks, 2/3 full, then sloshing become an issue when stopping. Not because of the new tounge weight up front, but because you run the risk of loading and unloading your rear end while trying to stop. Lateral mounting would be the easiest solution of you don't wanna use baffles.
TLDR: A modern (mid 2000s+) truck will not care as you are limited by the weight rating of your axle.
Hope the people pulling it have a hazmat. The fines will be in the 10's of thousands of dollars.I built one for the day job and centered the tank over the axles. It's on a tandem axle trailer, tank is a 150 gallons and tows relatively fine behind a 3/4 ton truck.
-Yes sloshing would be a dynamic thing IF there was no baffling. Member @Firebrick43 has posted that they all have cells in the absence of baffling. Even if there were no baffles/cells the tank(s) could possibly be mounted traverse if small enough that would negate some of the effect of sloshing as @baldy343 suggested. We can't just post statements about how trivial it is until we have dimensions now can we?Actually it is fairly trivial for any loading condition until you start talking about sloshing.
That's why I posted "if you have all the dimensions". I guess you missed that part. A pretty trivial thing to miss.For three tanks partially loaded, it is actually still pretty trivial to do the math, but you are going to get very different answers depending on the exact dimensions.
Curious about this for the same reason as 930.All of the manufactured mulit tank non hazmat fuel trailers have cells that are approx. 30" cubed. Sloshing is non existent with them. I haven't seen/driven a tank truck yet that has that much baffling.
Many of those trailers are non hazmat trailers and yes, they are limited to 119 per tank to be non hazmat. 30" cubes is 115 gallons, isn't to high, makes for a 60" ish wide trailer (minus wheels) so it tows neatly behind a pickup and its just a matter of 4, 6, or 8 cells for the trailer size needed.Curious about this for the same reason as 930.
Does the 30” cube cells also apply to the myriad of 500-900 gallon fuel and fuel/def trailers that have proliferated over the last eight or so years? I’ve never laid hands on one to check although I’m considering copying one myself.

