Hi ladies and gents,
I am planning and designing to build a travel trailer for a family of four. Approximate size of the living area: 5'6" wide, height 6'3", and length 18'. My goal is to keep total weight of the entire trailer with cargo below 2500-2800 lbs. However, I prefer chassis capable of supporting 3500 - 4000 lbs. I am designing for tandem axle; if weight is too low, I may downgrade to single axle. I am planning to have the trailer chassis with side beams and tongue beams as one piece as noted in the attached picture. See red circled area in the picture. By design, I prefer chassis to be strong enough to protect the cabin from flex, shear, and torsion etc. The cabin will have aluminum studs and skin, foam for insulation, and as little wood as possible. It will resemble a metal tent on wheels. I will have a professional welder weld the trailer main frame and install axles. Not want to build a tank; prefer to go lightweight (like airplane).
Based on following information, what size steel rectangular tubes should I use for the trailer chassis?
From an online vendor, I am getting following price and weight for four pieces of 24 feet long rectangular tubes. I anticipate I will use at least three of these studs.
4 X 2 X 14 GA (.083 wall) 314 lbs for $348
3 X 2 X 11GA (.120 wall) 374 lbs for $412
4 X 2 X 11 GA (.120 wall) 440 lbs for $452
6 X 2 X 11Ga (.120 wall) 620 lbs for $669
8 x 3 x 11GA (.125 wall) 866 lbs for $1,038
10 x 3 x 11GA (.120"" wall) 1028.16 lbs for $1,542
Thank you for your help.