t4r engineers, help please!

[brockeverly]

I am getting ready to start on a tongue extension on my camper, just want to bounce the information off of someone else's head, and we have a few engineers here so.....

Here is the deal. The camper has an allowable weight of 3000#, 1890# dry, 235# tongue weight dry. If I add a 2' extension to the tongue that weighs roughly 150# about how much can I expect the tongue weight to increase? I know that the optimal tongue weight is 10-15% of the total trailer weight, and I want to keep it as close as possible. In my mind it seems that the weight on the axle will stay around the same as the weight (existing + new) is now distributed over more space between the hitch and axle, and the tongue weight will go up. I also am trying to be mindful of our 500# allowable tongue weight (I would think I would be well below that even with my generators and firewood up front, but I am a salesman, not an engineer LOL)

I will be putting two 50# generators on the tongue for boondocking trips, and firewood on almost all trips. This will also increase the tongue weight, but again, I cannot find a formula for how much. I already carry these items in the trailer and in front of the axle, just not so close to the tongue.

Thanks for the help guys! :hatsoff:

 

[1engineer]

I am getting ready to start on a tongue extension on my camper, just want to bounce the information off of someone else's head, and we have a few engineers here so.....

Here is the deal. The camper has an allowable weight of 3000#, 1890# dry, 235# tongue weight dry. If I add a 2' extension to the tongue that weighs roughly 150# about how much can I expect the tongue weight to increase? I know that the optimal tongue weight is 10-15% of the total trailer weight, and I want to keep it as close as possible. In my mind it seems that the weight on the axle will stay around the same as the weight (existing + new) is now distributed over more space between the hitch and axle, and the tongue weight will go up. I also am trying to be mindful of our 500# allowable tongue weight (I would think I would be well below that even with my generators and firewood up front, but I am a salesman, not an engineer LOL)

I will be putting two 50# generators on the tongue for boondocking trips, and firewood on almost all trips. This will also increase the tongue weight, but again, I cannot find a formula for how much. I already carry these items in the trailer and in front of the axle, just not so close to the tongue.

Thanks for the help guys! :hatsoff:

Yeah, lot of replies to this thread aren't there! Nevermind. You can't find a formula because it requires several different ones depending on axles, loads, tongue design, etc. .

First of all, you gave no distances other than you are going to add 2 feet. Is the trailer 20 ft long, 50 feet long, 5 feet long? You also estimated (and admitted it?!) the tongue weight. Sadly, this is why sitting down and taking moments and doing cantilever load beam diagrams is what we won't be doing because, well, things change in projects like this, Weights change, length changes, amount of beer consumed is about the only constant, so here is a way to ease your mind that you are doing the right thing. You will need a few things for this little project, like bathroom scales (old school is better), a few big "C" clamps and some 2X4's.

1. First, put your trailer on your existing hitch. Measure the distance from the bottom of the tongue to the ground.
2. Cut a board to this length minus a few inches (height of the scale).
3. Disconnect the trailer, put the newly cut board under the tongue and put on the scale. What does it read? This is an approximate weight but will work fine for this little experiment.
4. Now, put that board aside and cut a few more boards 3-4 feet long. Measure two feet from one end and mark the board. Now clamp it to the existing hitch at the mark, letting the two feet extend past the point where the ball will go. Basically what you are doing is adding two feet of length with boards to your existing hitch so you can get a weight.
5. Now prop your other 2X4 under this setup and see what the new weight is.

The problem with trailers is the weight adds up real fast. Adding your generators and firewood is adding a lot of tongue weight so you might want to take that into consideration when doing this test.

Good luck. One good thing though is with a longer tongue the trailer will be easier to back up!

 

[Antman]

That's why I'm not an Engineer.
If I needed to add 2' to my trailer, I would just add the extension. Then I would hook it up to the truck, stand back, scratch my (balding) head, give it a good once over and have a coffee.

1engineer- your world is much more complex than mine! :shrug:

 

[Koz]

One way to tell;

Measuring trailer tongue weight with a bathroom scale

Koz

 

[philsey]

I'm curious as to your purpose in adding length to the tongue?

"I will be putting two 50# generators on the tongue for boondocking trips, and firewood on almost all trips"

What I take away from this is that the longer tongue is to put more stuff on the tongue. Is this correct?

 

[phillyd2]

No doubt we need them engineers to design stuff and stuff. The trouble starts when we let them out of the basement. :lol:

 

[brockeverly]

I'm curious as to your purpose in adding length to the tongue?

"I will be putting two 50# generators on the tongue for boondocking trips, and firewood on almost all trips"

What I take away from this is that the longer tongue is to put more stuff on the tongue. Is this correct?

Yes and no. Main goal is to allow my front bunk to open while attached to the truck to save time during one night stops when headed to further destinations. It would be nice to keep my gennys there, but not really my motivation.

 

[1engineer]

That's why I'm not an Engineer.
If I needed to add 2' to my trailer, I would just add the extension. Then I would hook it up to the truck, stand back, scratch my (balding) head, give it a good once over and have a coffee.

1engineer- your world is much more complex than mine! :shrug:

Yeah I know.

 

[brockeverly]

1engineer, I am lifting the trailer today so I can take some measurements if that would help ballpark this. When I am on a computer I will posta picture of the type of extension I plan to use as well.

 

[philsey]

Yes and no. Main goal is to allow my front bunk to open while attached to the truck to save time during one night stops when headed to further destinations. It would be nice to keep my gennys there, but not really my motivation.

Where I was headed, was to suggest you not load any more weight on your hitch. But I see now you have airbags, so ......... nevermind.

 

[Jtraskell]

I am getting ready to start on a tongue extension on my camper, just want to bounce the information off of someone else's head, and we have a few engineers here so.....

Here is the deal. The camper has an allowable weight of 3000#, 1890# dry, 235# tongue weight dry. If I add a 2' extension to the tongue that weighs roughly 150# about how much can I expect the tongue weight to increase? I know that the optimal tongue weight is 10-15% of the total trailer weight, and I want to keep it as close as possible. In my mind it seems that the weight on the axle will stay around the same as the weight (existing + new) is now distributed over more space between the hitch and axle, and the tongue weight will go up. I also am trying to be mindful of our 500# allowable tongue weight (I would think I would be well below that even with my generators and firewood up front, but I am a salesman, not an engineer LOL)

I will be putting two 50# generators on the tongue for boondocking trips, and firewood on almost all trips. This will also increase the tongue weight, but again, I cannot find a formula for how much. I already carry these items in the trailer and in front of the axle, just not so close to the tongue.

Thanks for the help guys! :hatsoff:

Not an engineer, but I have a suggestion. Since all the additional weight will be FORWARD, of what I gather by your write up, is a single axle trailer. I suspect much of that weight will show up on tongue weight. I could be very wrong.

Try this. Do what 1engineer said, under what I will call step 1. Cut a 2x4 so you can place a scale under the tongue, Then, place your generators on the existing tongue in the area you plan to place them. If the full weight (100lbs) shows up on the scale, then you will know that the rest should also show up. If only a portion shows up, do the percentage math, and see if you can get the rest. I think a good estimate for dry firewood would be at least 100 to 200 lbs. I would however, count the full 150 lbs of the extra steel for the extension since it is all the way at the end of the tongue. You should be able to make a good educated guess at that time. Good luck and be safe.

 

[Qjake]

How about another Gobi for the roof of the camper then you'll have no worries about the tongue weight other than the steel added to lengthen it. Of course you'll have to unload everything from it to raise the roof. Or a platform added to the rear bumper then load the tongue and bumper accordingly to even out the weight.

Why 2 generators? :shrug:

 

[brockeverly]

Two generators because I parallel them to run my AC unit during the summer months. Winter months I only carry one.

As for 100-200# of firewood, not even close for us. I carry two to four bags of wood similar to what you would find at a gas station. I am not sure the weight, but nowhere near 100#, let alone 200#.

Roof rack would be great, however, the camper is a popup so the roof cannot handle that kind of load. I have to keep it on the tongue or tail of the trailer.

 

[brockeverly]

Got the trailer lift done. I am pretty happy with it :frog:
Before:

After:

 

[Titanpat57]

I'll start off saying that I am not an engineer, and my opinion is worth what you paid me for it..

that being said...

I hang on a few trailer forums, mostly off road, and one consistent mod that keeps coming up is tongue redesign. Manufactured trailers are designed to carry certain loads and stresses, and I'm sure the people that design these, realize there are idiots like me that will never follow the rules, and always overload, etc. Yes, most will pass the test, a few will fail, and some will be catastrophic.

Tongue distribution, design, changes is a different ball of wax though, especially on a pre-built unit. Changes you may make to the tongue, may cause undo stresses back on the frame further, that it may have not been originally designed for. A miscalculation can result in injury to you, your family, or some innocent party (and your a smart guy,I know you know that Brock) Boon docking alone can subject some pretty serious forces on the trailer frame it may have been intended to go...but slow and easy will win the race.

My suggestion is to take the trailer to competent welder first of all, and span back further on the trailer, preferably under the existing tongue with some 2-1/2" x 2-1/2" x 3/16" (min) receiver steel, then angle some additional box steel as an added plus. Pictures always help...

Why "two" generators..if you say the AC, you're in big trouble...:banana:

I would consider making a metal pan and storing your firewood on the rack, in the center of the vehicle roof....good luck,

Pat

 

[philsey]

Your tractor-trailer rig looks good together. Have you thought about replicating that Coleman swoosh on the side of your LE?

:art:

:

 

[Kmvreter]

Yes and no. Main goal is to allow my front bunk to open while attached to the truck to save time during one night stops when headed to further destinations. It would be nice to keep my gennys there, but not really my motivation.

If this is the case then do you need the full 2' extension? Maybe you don't need to do anything to the trailer. I've seen hitch receiver extenders, particularly a 16" version (advertised as a 20" extension but actually 16" between the pin holes.) It's rated at 3500# with a reduced 350# tongue weight but that is still within your needs. Maybe that can work for you.

Consider that the trailer mod extension may possibly negatively impact future resale.

BTW, like the trailer lift. Would it be possible to start another thread with a quick writeup of the how to?

 

[Qjake]

If this is the case then do you need the full 2' extension? Maybe you don't need to do anything to the trailer. I've seen hitch receiver extenders, particularly a 16" version (advertised as a 20" extension but actually 16" between the pin holes.) It's rated at 3500# with a reduced 350# tongue weight but that is still within your needs. Maybe that can work for you.

Consider that the trailer mod extension may possibly negatively impact future resale.

BTW, like the trailer lift. Would it be possible to start another thread with a quick writeup of the how to?

^^This^^ might be a good idea Brock! Price is reasonable also.