How Many 25Litre Barrels Do I Need To Lift 270 Kilograms Weight In Seawater?

[gav1951]

I want to "float" a mooring assembly into position with my boat.

[fiction-factory]

270 kg of seawater is about 265 litres I think. So the answer is around 10 or 11. The weight and density of teh barrell material may be a factor though

[fiction-factory]

I may have misunderstood what is happening here though.

[gingejbee]

It might help if we knew the weight of an empty barrel......?

[Baldric]

Er, the barrels are not going to be full of seawater, they are going to be used as floats

[gingejbee]

...in that case....ask a sailor....

[fiction-factory]

Yes, From the title I thought gav needed to know how many barrels would he fill from 270kg of seawater, but from the question details if it's some sort of flotation device it'll depend on how it works. Are these going to be empty barrels (okay, filled with air)?

[fiction-factory]

Thanks Baldric, over to you then?

[alavahalf]

If the poly the barrel is made of is of neutral density .. then a 25 litre barrel will support just over 25 kilos in saltwater.. therefore ff's answer of 10-11 is correct.
But should you add any more weight onto the deck of the structure then extra barrels will be needed ie.
.. if you want to stand on it.
Add another barrel for every 25k that might be present on the deck at any one time.

[donny48]

Approx 14-15 barrels.

[ToraToraTora]

this explains it better that I could:
http://www.wikihow.com/Calculate-Buoyancy