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Eric W

@bct.org

How much will it float (55 gal plastic barrel)?

Building a dock what will a 55 gal barrel support?


jjoshua
Premium
join:2001-06-01
Scotch Plains, NJ
kudos:3
450lbs.


ttiiggy
Premium
join:2001-03-27
Bozeman, MT
reply to Eric W
Water weighs 8 pounds per gallon.
55 gallon barrel will theoretically displace 55 gallons of water.
8 x 55 = 440 pounds.

Subtract the weight of the drum...

Factor in whether the barrel is going to be completely submerged...

»Will it float (dock)?


Coma
Thanks Steve
Premium
join:2001-12-30
NirvanaLand
reply to Eric W
said by Eric W :

. . . what will a 55 gal barrel support?

At what temperature ?

Temp.    (lb/US gallon)
 
32         8.3436
40         8.3451
50         8.3430
60         8.3378
70         8.3290
80         8.3176
90         8.3077
100        8.2877
120        8.2498
140        8.2048
160        8.1537
180        8.0969
200        8.0351
212        7.9957
 

--
. . . seeking professional help . . .


Cho Baka
Premium,MVM
join:2000-11-23
there
kudos:2
If it is for a dock, I am guessing that 212 is out of the question.

--
Striving for Parfection.


alphapointe
Don't Touch Me
Premium,MVM
join:2002-02-10
Columbia, MO
kudos:2
HOT LAKE!
HOT LAKE!


Coma
Thanks Steve
Premium
join:2001-12-30
NirvanaLand

1 recommendation

reply to Cho Baka
said by Cho Baka:

If it is for a dock, I am guessing that 212 is out of the question.


From a dictionary . . .

dock |dk| |dk|
noun (usu. the dock)
the enclosure in a criminal court where a defendant is placed.

. . . or lovingly referred to as the HOT SEAT.



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. . . seeking professional help . . .


cdru
Go Colts
Premium,MVM
join:2003-05-14
Fort Wayne, IN
kudos:7
reply to Coma
said by Coma:

At what temperature ?
That's only a difference of ~19 lbs between 32 and 212 degrees. If your margin of safety is less then 20 lbs such that temperature is an factor, you have a design problem.


MoJeeper
The Stig in 2012
Premium
join:2000-10-20
Springfield, MO

1 recommendation

reply to Eric W
3 Barrels won't float a shark so the should do well on a boat dock.
--
Branded a Domestic Terrorist by the establishment.

8744675

join:2000-10-10
Decatur, GA
reply to Eric W
The floating docs I've built or been on have had either 4 or 6 barrels. With 4 barrels, it would tend to dip with too many people on it. The docks with 6 barrels had 3 barrels laid end-to-end on opposite sides of the dock. Use nylon rope or strapping to secure the barrels to the dock. Metal strapping (before nylon was available) was dangerous due to the sharp edges and rusted out quickly.

wth
Premium
join:2002-02-20
Iowa City,IA
Reviews:
·Mediacom
reply to Eric W
Use plastic drums to, not steel. If in a public lake/waterway, you may want to check with local officials, as I know some floating homes now are required to have Styrofoam instead of plastic drums under them, as you can punch a hole in Styrofoam, and it won't bother anything.


KrK
Heavy Artillery For The Little Guy
Premium
join:2000-01-17
Tulsa, OK

1 recommendation

Even better... Plastic Drum filled with styrofoam. They'll never sink.


cdru
Go Colts
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join:2003-05-14
Fort Wayne, IN
kudos:7
said by KrK:

Even better... Plastic Drum filled with styrofoam. They'll never sink.
They will if you put enough weight on them.


KrK
Heavy Artillery For The Little Guy
Premium
join:2000-01-17
Tulsa, OK
said by cdru:

said by KrK:

Even better... Plastic Drum filled with styrofoam. They'll never sink.
They will if you put enough weight on them.
True. Until the weight falls off and they pop back up.

So maybe I should say "They'll never STAY sunk"
--
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exocet_cm
Free at last, free at last
Premium
join:2003-03-23
New Orleans, LA
kudos:3
reply to KrK
said by KrK:

Even better... Plastic Drum filled with styrofoam.
That is a really good idea, IMO.

@Op: How are you going to anchor the dock? Need some really sturdy/permanent otherwise your dock will be a raft.
--
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Langning
Premium
join:2003-04-28
Marlborough, MA
reply to Coma
said by Coma:

said by Eric W :

. . . what will a 55 gal barrel support?

At what temperature ?

Temp.    (lb/US gallon)
 
32         8.3436
40         8.3451
50         8.3430
60         8.3378
70         8.3290
80         8.3176
90         8.3077
100        8.2877
120        8.2498
140        8.2048
160        8.1537
180        8.0969
200        8.0351
212        7.9957
 

I assume those numbers are at sea-level at 1 atmospheric pressure, right? :)


natedj
Elected
Premium
join:2001-06-06
Columbia, SC

1 edit
reply to Eric W
For some reason my logic tells me that a Styrofoam fill drum would be less buoyant than an empty one because it will simply weigh more. The styrofoam won't provided any buoyancy since it's not in direct contact with the water.
Now if you had a drum-shaped Styrofoam, it will be more boyant than an empty drum.
--
Good judgement comes with experience...Experience comes after bad judgements

Langning
Premium
join:2003-04-28
Marlborough, MA
said by natedj:

For some reason my logic tells me that a Styrofoam fill drum would be less buoyant than an empty one because it will simply weigh more. The styrofoam won't provided any buoyancy since it's not in direct contact with the water.
Now if you had a drum-shaped Styrofoam, it will be more boyant than an empty drum.
Your logic is wrong. Buoyancy is the amount of water it can displace. Given the same (square footage of) surface, a ball will have more buoyancy than a drum.


DarkLogix
Texan and Proud
Premium
join:2008-10-23
Baytown, TX
kudos:3
for Buoyancy you need to use volume not surface area to figure out the buoyant force

Langning
Premium
join:2003-04-28
Marlborough, MA
said by DarkLogix:

for Buoyancy you need to use volume not surface area to figure out the buoyant force
That is what I said. For the same surface area, a ball would yield the most volume -- thus the most buoyancy.


natedj
Elected
Premium
join:2001-06-06
Columbia, SC
reply to Langning
said by Langning:

said by natedj:

For some reason my logic tells me that a Styrofoam fill drum would be less buoyant than an empty one because it will simply weigh more. The styrofoam won't provided any buoyancy since it's not in direct contact with the water.
Now if you had a drum-shaped Styrofoam, it will be more boyant than an empty drum.
Your logic is wrong. Buoyancy is the amount of water it can displace. Given the same (square footage of) surface, a ball will have more buoyancy than a drum.
So you're saying that an empty drum will be easier sunk than a drum filled with styrofoam? I'm talking about the ability to stay afloat when subjected to the a same weight above them.
--
Good judgement comes with experience...Experience comes after bad judgements


just anon

@wednet.edu
I think you are on the right track. If the drum is sealed the styrofoam would be kind of like cargo in a ship - and make the overall unit less bouyant. While the drum is sealed, the drum would provide the buoyancy . If the drum is punctured and fills with water, the styrofoam would provide the buoyancy and the overall unit would be weighed down by the plastic barrel - assuming the plastic is denser than water.

A cargo ship filled to the top with styrofoam would ride lower in the water than an empty ship. If the ship had a hole punched in it and flooded, and there was enough styrofoam, the styrofoam would provide bouyancy and keep the ship afloat - once submerged and if it was contained and didn't float away.


DataDoc
My avatar looks like me, if I was 2D.
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Martinsburg, WV
Reviews:
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·Suddenlink
reply to MoJeeper
said by MoJeeper:

3 Barrels won't float a shark so the should do well on a boat dock.
Only in Hollyworld.
--
To equate judgment and wisdom with occupation is insulting.


DataDoc
My avatar looks like me, if I was 2D.
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Martinsburg, WV
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·Comcast
·Suddenlink

1 edit
reply to Langning
said by Langning:

Buoyancy is the amount of water it can displace. Given the same (square footage of) surface, a ball will have more buoyancy than a drum.
That can't be right, or a drum full of concrete would be just as buoyant as an empty or Styrofoam-filled one. Weight of material vs weight of water displaced has to come in there, too.
--
To equate judgment and wisdom with occupation is insulting.


Locutus65
Why bother?
Premium
join:2001-05-24
Houston, TX
kudos:2
reply to Eric W
Why is it that this discussion makes me think of King Arthur having a discussion about coconuts?
--
The only thing we have to fear is Fear itself...... and spiders.

jfmezei
Premium
join:2007-01-03
Pointe-Claire, QC
kudos:23
If you want your deck to be above water, you need to factor that if your drums are up against the floor of the deck between the studs, a significant portion of the drums will be above water an provide no bouyancy unless you have enough people on board to cause the deck to sink to a point where all of the drum is underwater.

And technically, you need to factor not only the weight of the drum itself, but also the air in it. If you vaccum the drum completely, the drum will weight less and thus provide greater bouyancy. (but that is pedantic argument, in real life the difference won't matter much).

In a 747 at altitude, pressurising the cabin to acceptable levels adds over one tonne of air to the plane, and that is one more tonne the wings must carry. So on that scale, it matters. But for a deck, the volume in the barrels won't matter much.

About styrofoam: there are many jurisdiction where styrofoam floats are banned. They break apart, and the small chunks of styrofam either pollute the shores or worse, they get eaten by wildlife who get sick by them.

There are types of styrofoam which are approved and types which are not. And some which end up becoming water laden over the years and lose their boyancy.


milnoc

join:2001-03-05
H3B
kudos:2
reply to Locutus65
said by Locutus65:

Why is it that this discussion makes me think of King Arthur having a discussion about coconuts?
African or European swallow?


Locutus65
Why bother?
Premium
join:2001-05-24
Houston, TX
kudos:2
said by milnoc:

said by Locutus65:

Why is it that this discussion makes me think of King Arthur having a discussion about coconuts?
African or European swallow?
I believe, considering the size of the drum, an African swallow would surely be the smart choice
--
The only thing we have to fear is Fear itself...... and spiders.


MemphisPCGuy
Taking Care Business
Premium
join:2004-05-09
Memphis, TN

1 edit
reply to DataDoc
the drum displaces 450#... so your filler reduces the effective lift by its weight. A 55gal (plastic ~22lbs) drum of concrete is close to 972#'s so would sink twice

Styrofoam weighs approximately 5% of water or .4lbs

So a 55gal drum (weighing about 22lbs) filled with styrofoam ( about 22lbs) would lift 410lbs

Of course, once its punctured the styrofoam barrel will still float... the concrete barrel would still be on the bottom
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pawpaw

join:2004-05-05
Greenville, SC

1 recommendation

reply to Eric W
A drum will support 2 Europeans, 5 Africans or 1 American.