[ArrogantBustard]

The risers on these pallets look like 2x4 instead of 1x4, and the top & bottom look like 1x? instead of half x ?.

IOW the pallets are stronger than normal. Strong enough not to collapse under 6 tons?

[Travis McGee]

Looking at the bottom most pallet on the right side, the one where you can see the corner near the floor, gives a pretty good opportunity to turn this into a simple engineering calculation. The edges of the gold do not quite extend to the vertical riser. That is, they are entirely over the horizontal wood, but very close to the edge of the vertical riser.

This puts 1/3 the entire weight of the entire stack above directly onto that edge, where the horizontal plywood floor meets the vertical riser. (1/3, because 1/3 is on the center vertical riser, and one third is on the opposite side vertical riser.)

This reduces the entire problem to a simple sheer strength equation. 1/3 of the entire weight of the stack above that point, against that plywood, in sheer.

Would it hold, or would it fail?

We need to know the exact weight of the gold above, and the sheer strength of the plywood.

I think that data should be right in a civil engineering text book, if we can make assumptions about the horizontal wood's compression, tensile and sheer strength.