Re: Freedom Ship - Most Advanced Freedom Project Yet

James Rogers (jamesr@best.com)
Fri, 10 Oct 1997 16:53:34 -0700


At 03:19 PM 10/10/97 -0700, Freespeak wrote:

[...SNIP...]
>In conception, 'Freedom Ship' seems to be one of the
>most advanced freedom projects I know of. It's a
>project to build a huge ship, three times as long as
>the Empire State Building is tall -- 4310 ft. long,
>725ft. wide. It will have a superstructure, rising
>25 stories above its deck. It will have space for
>at least 50,000 residents, 15,000 personnel, and
>20,000 guests and visitors.
[...SNIP...]

There appears to be an engineering problem with the design, namely the size.

In an ideal rigid floating body, the net buoyancy of the object is uniform
across the entirety of the bottom of the object. In reality this is never
the case. The problem is that these variations in buoyancy generate
stressful forces on the ship that grow geometrically as the length grows
arithmetically. At some point the stresses will tear the ship apart.

Very large ships, such as supertankers ( which are much smaller than the
"Freedom Ship" ), are very fragile and have to be loaded in a manner that
distributes the mass evenly throughout the ship. A momentary increase in
mass in one part of the ship can cause the ship to rip itself in half.
Sailing through rough seas with a less than optimally balanced load will do
the same thing.

According to the resume on the site, the guy who designed the "Freedom
Ship" did not have the design of very large water-craft in his engineering
expertise.

FTR, I am no expert on this type of engineering either, but I've had
lengthy discussions in the past on this topic with a guy who is an expert,
both as an engineer ( wrote design software for this type of thing ), and
as a former supertanker captain.

A more feasible design would be to either have a bunch of smaller floating
objects connected non-rigidly, or to make the structure stacked *a lot*
shorter (minimize vertical pressure) so that the superstructure will be
capable of withstanding the buoyant forces. A structure that is both long
*and* tall simply won't work. Either way, it will be a serious compromise
to his "ideal" design.

-James Rogers
jamesr@best.com