Channel or RHS for trailer Chassis

[TrewithickFarm]

Just a question to satisfy my wondering....

Why do some trailer manufactures use Channel for the chassis and others use RHS?

Thanks
Steve

 

[TechWise]

Channel doesn't hold water and dirt inside and rust from the inside out. RHS is available in a far greater range of sizes and thicknesses in my experience.

I'm sure someone more knowledgeable will provide a better answer.

 

[Andrew]

If a trailer is designed to twist and flex, for example artic trailers (5th wheel has no sideways pivot so the trailer chassis does it) they tend to use an I beam / channel style chassis.

Straight pull trailers such as the majority of ag trailers, twist is a very bad thing, so they use box which Is a lot stronger in torsion.

Some ag trailer manufacturers use C section with a cap plate welded on to make a box, but haven’t seen any open section chassis on new ag trailers for years.
They may choose to use C section with a cap as it is stronger in one direction (top and bottom of the C are thicker than the wall). You can laser cut the cap plate for hoses and fittings, a lot easier than making holes in box.