Charlie Morgan wrote:
On 22 Jan 2007 11:43:42 -0800, "Joe" wrote:


otnmbrd wrote:
"Ellen MacArthur" wrote in
reenews.net:


"otnmbrd" wrote
deleted it this time

Oh, something to ask an expert. Look at the dent in the top of
that container.
Doesn't it look like the corner of another container got dropped on
top of it?

Entirely possible


Maybe more than one fell off the ship and the one in the
water got hit by another one dropping down on it???

Entirely possible.

And why do they float? Do they have waterproof gaskets on the
doors?

Not a container expert but the reefers are far better sealed than the non
reefers. All containers have a pretty good seal but I wouldn't call it
"waterproof".
As for floating...... depends on what's inside..... load of lead, sink like
a rock..... load of packing peanuts in hermetically sealed bags, float
forever.

reefers also have foot thick foam walls, great floation.

Joe


Do the math, Joe. a foot thick foam lining is not going to float a
flooded container.

I said it provided great flotation. A 20' box has a volume of just
over 1341 cubic feet, and a 40' box a volume of 2719 cubic feet. The
density of sea water really depends on a number of variables, including
the temperature, the amount of salt and whatever other foreign items
may be present, and the depth, thus the pressure, but basically at the
surface, on average just over 64.1 lbs per cubic foot. The forces
required to push the box under the water, or to sink it, must therefore
exceed the volume of water to be displaced. A 20' box is allowed a
maximum gross weight of 63,800 pounds and a 40' box a maximum of
67056 lbs. It therefore seems that if either size of container is
watertight and not overloaded then it will float. Foam provides great
flotation, i'd guess most container lost far offshore that make it to
land are reefers.

Anyhow BB, your claim to be a Harvard Man... if the seal was leaking on
the small 20 ft container... and it was taking on 3 gallons of seawater
per hour, how many days will it take to sink?


Joe








CWM