are 4, full length, 5" tall c channel steel main beams sufficient for a 30 ft gooseneck trailer? I'm planning on putting a 4k lb camper on the front and my 40 or 60 behind that.
30 ft gooseneck design questions (13 Viewers)
- Thread starter Mace
- Start date
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splitshot
Head cook, Bottle washer, and Peace keeper.
Just me, but I would be thinking I-beam for that length and load. Also we have found the trailer dealers pump out a product, that is less expensive vs building. Just a thought...
- Thread starter
- #3
I already have the trailer. I'm just making sure that if I put my cabover on it and the 60 it'll be in the ballpark at least. If I have to, ill convert the outer channels to a thicker material.
splitshot
Head cook, Bottle washer, and Peace keeper.
Gotchya,
I tend to overbuild, without looking at it, I would see if there is some 5x rectangular tube available. Channel has a tendency to bend under stress unless boxed in.
ntsqd
technerd
None of the structural shapes have much torsional strength.
As to if its strong enough, would need to know dimensionally where the support points are. Wet thumb in the wind answer is probably. Who built it? Picture(s)?
As to if its strong enough, would need to know dimensionally where the support points are. Wet thumb in the wind answer is probably. Who built it? Picture(s)?
ntsqd
technerd
Was it something else, like a travel trailer, when it was originally built? 4 longitudinal main frame rails is unusual in a trailer. Are they rolled structural steel beams, or bent up from sheet steel?
ntsqd
technerd
Torsional strength will increase significantly, but bending strength won't increase by much. Load capacity is in the top and bottom flanges. The further apart that they are the more load that they'll carry. Another of those counter-intuitive things, seems like the load would be carried in the flat sides, but consider an I-beam's shape and how it's best loaded. If you want a stronger I-Beam you'll end up with one that is taller more than one with a thicker web. All the web does is keep the flanges equi-distant apart. Same is true of the fabricated roof beams; note that the flanges are real lumber while the web is usually particle board.
More load capacity would be more easily achieved by adding a "strong-back" "fin" to the middle of the lower flanges, and then running a piece of strap about the same width & thickness as the 'C''s flanges down the length of the strong-back - effectively turning the lower flange of the 'C', the fin, and the strap into a fabricated I-Beam. Start and finish the strong-back with a taper so that the strap can be welded directly to the existing flanges of the 'C' beams at each end.
Was it me, I'd try it as-is. I think that there's enough structure there to work. I'm more concerned about the way that the tongue is shaped and attached to these rails.
More load capacity would be more easily achieved by adding a "strong-back" "fin" to the middle of the lower flanges, and then running a piece of strap about the same width & thickness as the 'C''s flanges down the length of the strong-back - effectively turning the lower flange of the 'C', the fin, and the strap into a fabricated I-Beam. Start and finish the strong-back with a taper so that the strap can be welded directly to the existing flanges of the 'C' beams at each end.
Was it me, I'd try it as-is. I think that there's enough structure there to work. I'm more concerned about the way that the tongue is shaped and attached to these rails.
ntsqd
technerd
I'd try it as is. Looking at the first pic again it doesn't look like there's room above the axles for adding much.
I'll guess that the camper will need a significant "spacer" under it to clear the 'neck. If you're really worried about it expose the rails from above and stack a second 'C', 'I', 'T', or box section on top of the existing. Just be sure to gently taper the ends. Not for toe stubbing issues, though that's important too, but to gradually change the bending strength of the frame. A sharp end on the doublers would be a massive stress riser.
I'll guess that the camper will need a significant "spacer" under it to clear the 'neck. If you're really worried about it expose the rails from above and stack a second 'C', 'I', 'T', or box section on top of the existing. Just be sure to gently taper the ends. Not for toe stubbing issues, though that's important too, but to gradually change the bending strength of the frame. A sharp end on the doublers would be a massive stress riser.
I have some plans for a gooseneck that may help. Interested?
A 4000 lb camper?
Add an i-beam
ntsqd
technerd
Mace, you gotta step it up. I just read that an Early Bronco owning friend's truck camper weighs 4500 lbs. Got 600 lbs worth of Dutch Ovens or something?
