AST with skids: structural slab needed?

[Biofuel]

I'm looking at installing a 6K gallon above ground storage tank (AST) with skids attached. The site is essentially flat and already developed (paved with asphalt). Does anybody know if a structural slab (concrete or otherwise) is typically required for a 6K (or smaller) AST? When full, the AST will weigh about 50K lbs.

It seems like the skids alone would suffice for structural support. However, I've seen these portable AST's installed both with and without a concrete slab. My structural engineer doesn't know why or when the slab is required for these tanks, so any info is appreciated.

 

[gr2vessels]

It has to do perhaps with the bearing capacity of the substrate;- say 50,000lb divided by the area of the skid baseplate will give an indication of the load to be compared with the bearing capacity...I'm sure your civil engineer can work out the allowables, unless he's taking someone for a ride...
cheers,
gr2vessels