[mr_hammer]

I regularly see steel ingots being prepared for a melt furnace stacked that way and there is nothing unusual about the wood skids holding up under the forces you can see in the photo.

I have stacked over 6000 lbs of steel on a wooden skid for storage with little problems.

P.S. many heavy equipment riggers load a 20,000 pound piece of equipment on a few oak 4x4 and ship the machine over the road that way.

[Travis McGee]

I have no problem with your numbers, when you are talking about a load (steel beams, heavy equipment on a full length steel skid) bearing down on the risers in compression. No problem at all.

But if you look carefully at the bottom corner of that bottom pallet on the right, you can see it's not lined up in compression, as they would be if the ingots bridged between the risers.

The ingots do not extend over the risers. There is no bridging effect, or very little. MOst of the load is in SHEER where the horizontal floors meet the vertical risers.

As you know, the horizontal wood's sheer strength is only a fraction of its compressive strength.