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Comment by dgrin91 | Hacker News Reader

Can you tell if there is actually 37 tons of sand there? 37 tons seems like... well.. a ton of sand for lack of a better phrase. In the video it seems like there was only few inches over a moderately sized park. It doesn't seem like its really 37 tons. Maybe though it just doesn't show the whole park, or I'm just bad at estimating.

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Sand weighs ~100 lbs per cubic ft.

37 tons = 74000 lbs or 740 cubic ft

3 inches of depth gets you 4 sq ft of coverage

740*4 gets you 2960 sq. feet.

The city says the park is 14,000 sq feet. [1]

In the video you can see they avoided spreading it in a lot of areas because they didn't have nearly enough!

Conclusion: Sand is heavy

[1] https://www.san-clemente.org/Home/Components/FacilityDirecto...

To put that in context: 1 cubic foot of flour is 37 lbs; of sugar, 50 lbs; of water, 62 lbs.

If you've ever tried to pick up a sack / large bucket of any of these things, it's like that but even denser. Compound that by the usual "volume varies as the cube of a side" thing, and this gets really heavy fast.

The easiest way to estimate/visualize it is that the normal dump trucks you see on the road are 20 ton dump trucks. So at a maximum it's two dump truck loads, which doesn't go very far. In reality sand is pretty dense/heavy so it's even less than that.

one ton of sand is about a 2 foot cube, so 37 tons would be about 12 feet by 12 feet by 2 feet deep, they really only need to fill in the bottom part of the skate park to render it mostly useless.

image search for one ton of sand, you'll see that it fits in a large bag.

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