chassis question

[scalelover]

I know this is probably a newbie question, but what is the purpose for double stacking the chassis rails on some of the builds. Ive seen it on many builds where you will have your standard chassis rail set then have a section where there is another set bolted directly on top of it. It may not run the entire length, or ive seen it front to back too, but both rails just sit parallel no drop areas or anyhting???

I figured that maybe it's just be used for more mounting room of components and or raising body height but I honestly have no idea and dont want to sound lke a dumbarse guessing about it.

I know that some of the dump beds have rails bolted to the bottoms to allow for operation of it tilting etc etc. Ive also seen some use extra rails to allow a section to sit lower down or higher up for beds

I cant upload pictures to show what I'm talking about right now but I'm sure you guys can figure it out

I appreciate any help you guys could give me on this as I'm feeling slightly less than retarded on this....lol

--Dan