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I watched on TV as they where showing gold bars stored in bank vaults and I noticed that they always stack them with the narrow side down and the wide side up. Like this:

Gold Bar Stacking

So there has to be a mechanical reason why is that. Any ideas?

John Alexiou
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    Few of us have ever had a chance to handle gold bars like that, but lead bricks are not so uncommon. Ever tried to pick one up? You need every advantage you can get, and you dare not drop one. // Once stacked 2500 pounds of lead brick like legos in one day (for a shielded instrumentation hut in a accelerator or end-station). I was in good shape at the time and I was still sore for days. – dmckee --- ex-moderator kitten Apr 23 '11 at 23:29
  • BTW--My inclination is to close this as off-topic. Anyone care to defend it as a physics question? – dmckee --- ex-moderator kitten Apr 23 '11 at 23:30
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    Working in a British higher education establishment how to handle gold bars was a constant issue – Martin Beckett Apr 24 '11 at 03:57
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    From the good delivery rules (page 10, "Shape"): "Bars must be ingot-shaped (i.e., having a trapezoidal cross section, both along the length and across the width of the bar) with sufficient undercut to facilitate handling but without resulting in the width of the bottom surface being so narrow that the bar cannot be safely stacked. " . The LBMA is the London Bullion Market Association. They are considered the ones to set the standard. – Floris Jan 21 '16 at 23:47

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They do not always seem to be that shape. For some cuboids which are not designed to be moved regularly, see this picture from Fort Knox.

But for bullion bars in the world market (about 10.9-13.4 kg of gold) which have the standard sort of trapezium cross-section, the top when casting is the wider area to get them out of the mould, so the wider area is defined as the "top" in the international specification) and the fineness, hallmarks and serial numbers usually stamped on top (as illustrated here). Stacking them top face up makes these easier to read for the bars on top, as well as easier to move. Pure gold bars may dent if dropped because of gold's softness, requiring recasting, so some care is needed.

Henry
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The primary reason I have usually heard is that this makes it easier to lift them.

Pure gold is quite smooth, and very dense, and would be near impossible to lift from the other side.

Chris Cooper
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