Our assignment is to create a boat made out of solely milk cartons and
duc tape. With unlimited amounts of only these two supplies, the boat
must be able to float 50 yds of a awimming pool. Now the hard part is
that someone has to maneuver the boat, meaning that it must float
carrying at least 125 lbs. Are there any suggestions as to how many
cartons would be roughly needed to hold up a person and stay afloat at
the same time? Also, any suggestions to the shape of the boat which
would maintain the most bouyany? Thanks!

"areuKIDDINGme" wrote in message
om...
Our assignment is to create a boat made out of solely milk cartons and
duc tape. With unlimited amounts of only these two supplies, the boat
must be able to float 50 yds of a awimming pool. Now the hard part is
that someone has to maneuver the boat, meaning that it must float
carrying at least 125 lbs. Are there any suggestions as to how many
cartons would be roughly needed to hold up a person and stay afloat at
the same time? Also, any suggestions to the shape of the boat which
would maintain the most bouyany? Thanks!

Water is 64# per cubic foot. So to support at least 125# and not be
partially submerged, you will need at least 3 cubic feet of milk cartons.
Go some more, and the boat will float higher, and be easier to paddle. A
rectangle will give the most bouyancy in the smallest area. But, for style
points, make it pointy in front of the rectangle.
Bill

Calif Bill wrote:
Water is 64# per cubic foot.

Water is 64# per cubic foot.

How'd you arrive at that? 'Cuz I'm driving myself nuts here trying to
convert lbs/gal (8.333) to lbs/cu.ft. and it's not working.

So to support at least 125# and not be
partially submerged, you will need at least 3 cubic feet of milk cartons.

Don't forget to add the weight of at least 3 rolls of duct tape, which
will another 5 lbs.

So to support at least 125# and not be
partially submerged, you will need at least 3 cubic feet of milk cartons.
Go some more, and the boat will float higher, and be easier to paddle. A
rectangle will give the most bouyancy in the smallest area. But, for style
points, make it pointy in front of the rectangle.

Would a shorter wider "beam" provide more bouancy than a longer narrower
one?

What a fun project!

--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://www.seaworthy.com/html/get_ri...oat_odors.html

"Peggie Hall" wrote in message
...
Calif Bill wrote:
Water is 64# per cubic foot.

Water is 64# per cubic foot.

How'd you arrive at that? 'Cuz I'm driving myself nuts here trying to
convert lbs/gal (8.333) to lbs/cu.ft. and it's not working.


Out of the past, from engineering school. Salt water is a little heavier.
Fresh maybe 62# and average salt water 64#. Been a long time since I
graduated.

So to support at least 125# and not be
partially submerged, you will need at least 3 cubic feet of milk
cartons.

Don't forget to add the weight of at least 3 rolls of duct tape, which
will another 5 lbs.

So to support at least 125# and not be
partially submerged, you will need at least 3 cubic feet of milk
cartons.
Go some more, and the boat will float higher, and be easier to paddle.
A
rectangle will give the most bouyancy in the smallest area. But, for
style
points, make it pointy in front of the rectangle.

Would a shorter wider "beam" provide more bouancy than a longer narrower
one?

What a fun project!

--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://www.seaworthy.com/html/get_ri...oat_odors.html



Beam width does not matter. Is how much displacement. Narrow beam would be
tippy. Noah's ark, would have been a box shape. No need for any pointy
end. As it was not powered, just drifted with the winds. And a box gave
the most capacity for size.

How'd you arrive at that? 'Cuz I'm driving myself nuts here trying to
convert lbs/gal (8.333) to lbs/cu.ft. and it's not working.

7.5 gallons per cubic foot

bc

Peggie Hall wrote in message ...
Calif Bill wrote:
Water is 64# per cubic foot.

Water is 64# per cubic foot.

How'd you arrive at that? 'Cuz I'm driving myself nuts here trying to
convert lbs/gal (8.333) to lbs/cu.ft. and it's not working.

Bill, I think, is using the weight of salt water, which is 64# per
square foot, but close enough. Fresh PURE water is 62.5 pounds per
cubic foot, and there are 7.5 gallons per cubic foot.
(8.33333x7.5)=62.5 (rounded!)

basskisser wrote:

Peggie Hall wrote in message ...

Calif Bill wrote:

Water is 64# per cubic foot.


Water is 64# per cubic foot.

How'd you arrive at that? 'Cuz I'm driving myself nuts here trying to
convert lbs/gal (8.333) to lbs/cu.ft. and it's not working.


Bill, I think, is using the weight of salt water, which is 64# per
square foot, but close enough. Fresh PURE water is 62.5 pounds per
cubic foot, and there are 7.5 gallons per cubic foot.
(8.33333x7.5)=62.5 (rounded!)


You meant, of course, 64 pounds a cubic foot for salt water, not a
square foot. All these cubes and squares...

Harry Krause wrote in message ...
basskisser wrote:

Peggie Hall wrote in message ...

Calif Bill wrote:

Water is 64# per cubic foot.


Water is 64# per cubic foot.

How'd you arrive at that? 'Cuz I'm driving myself nuts here trying to
convert lbs/gal (8.333) to lbs/cu.ft. and it's not working.


Bill, I think, is using the weight of salt water, which is 64# per
square foot, but close enough. Fresh PURE water is 62.5 pounds per
cubic foot, and there are 7.5 gallons per cubic foot.
(8.33333x7.5)=62.5 (rounded!)


You meant, of course, 64 pounds a cubic foot for salt water, not a
square foot. All these cubes and squares...

Yup, shouldn't use math so early in the morning.

Harry Krause wrote:

basskisser wrote:

Peggie Hall wrote in message
...

Calif Bill wrote:

Water is 64# per cubic foot.



Water is 64# per cubic foot.

How'd you arrive at that? 'Cuz I'm driving myself nuts here trying to
convert lbs/gal (8.333) to lbs/cu.ft. and it's not working.



Bill, I think, is using the weight of salt water, which is 64# per
square foot, but close enough. Fresh PURE water is 62.5 pounds per
cubic foot, and there are 7.5 gallons per cubic foot.
(8.33333x7.5)=62.5 (rounded!)



You meant, of course, 64 pounds a cubic foot for salt water, not a
square foot. All these cubes and squares...

Why bother?

A 75 kg load needs 75 one liter milk cartons, not counting the
weight of the cartons and tape.

Close enough!

So, How heavy is the load plus the vehicle?

Ahh, boat design, so simple, so elegant.

I want to make closed cell urothane foam cushions for my cockpit,
maybe 2" thick. The cusions would velcro together to make a dinghy.
It don't matter if it leaks, it'll be self bailing. With a drop
board for a keel and an umberella, it'll do for fishing expeditions
to "the surface", kind of like a little shuttlecraft.

Terry K

Hi, Over here in Perth, Western Australia we have an annual "Milk Carton
Regatta". Here is the link.
http://www.newmanjunior.wa.edu.au/regatta/regatta.html






"areuKIDDINGme" wrote in message
om...
Our assignment is to create a boat made out of solely milk cartons and
duc tape. With unlimited amounts of only these two supplies, the boat
must be able to float 50 yds of a awimming pool. Now the hard part is
that someone has to maneuver the boat, meaning that it must float
carrying at least 125 lbs. Are there any suggestions as to how many
cartons would be roughly needed to hold up a person and stay afloat at
the same time? Also, any suggestions to the shape of the boat which
would maintain the most bouyany? Thanks!