By Lisa Busch
the first fishing vessel plied the sea, humans have dreamed of new ways
to tap into the world's ocean resources. Using ocean waves to generate
power, feeding the hungry with seaweed, and desalinating seawater are
some of the grander schemes. Recently, a few new ideas have landed on
the horizon that have engineers thinking really big. A floating military
base, an at-sea container-ship transfer station, and a floating city
may be the next generation of ocean frontiers.
military base called a Mobile Offshore Base (MOB) would be the largest
floating structure ever constructed. The idea behind the MOB is that
a one mile by 300 meter floating base could be deployed in international
waters anywhere in the world. Though the estimated $10 billion dollar
price tag on the MOB is daunting, its creation could theoretically mean
a long-term savings by providing an as-needed military base rather than
operating one for years that is only utilized every few decades. The
MOB would be a semi-submersible structure that has a million square
feet of storage, holds 10 million gallons of fuel, and houses 3,000
would be constructed by connecting five or six semi-submersible modules,
each two or three times the size of a standard oil drilling platform.
Ronald Riggs, a professor of civil engineering at the University of
Hawaii at Manoa, worked on the MOB project. He believes that while the
large size is new, the technology is not. It's evolutionary,
not revolutionary,'' says Riggs. Still, the giant floating
structure requires some major innovations from the engineering community.
of Naval Research contracted with different firms to come up with the
best system to connect the floating modules. One connection idea is
a railroad hitch design. Another company designed the modules to be
positioned quarter-miles apart connected by an accordion-type bridge
running through a hollow truss. A third company designed the units to
be 50 feet apart. In this design, the modules wouldn't even be
physically connected, but would be kept in close proximity by a computer
system that was constantly repositioning the modules to stay grouped.
If the wind or waves changes direction, for example, so would the modules.
One of the difficult aspects of the MOB is determining the effects of
waves on a structure this size. Because there is no wave tank in existence
to study how a mile-long object could be impacted, MOB researchers did
some basic wave research with the National Atmospheric and Space Administration.
NASA flew a plane into a hurricane to snap pictures of extreme wavesat
least one of which was over a mile long.
of Defense spent $36 million and five years developing MOB. The
take-home message is that the engineering is there and this is not a
crazy idea,'' says Paul Palo, the technical manager for the
MOB effort. But just because something is technically feasible does
not guarantee its political acceptance. After the Washington-based think
tank the Institute for Defense concluded there is no reason to build
the MOB, Congress deep-sixed the research program, at least for the
time being. Meanwhile, the private sector is trying to apply MOB research
to the world of ocean transportation through an idea dubbed Seahub.
The concept is that one modified module of the MOB could be designed
to be a floating cargo-ship transfer station.
companies are planning to improve efficiency by building larger and
larger vessels that can haul more containers. Currently, most ships
carry about 1,500 containers, but the new superships are expected to
carry over 15,000 containers. While moving more quantity faster is theoretically
more efficient, the superships will be too large to dock in many U.S.
ports. Rather than dredging harbors, which can be costly and have deleterious
impacts on the marine environment, Seahub could create a port at sea
where large vessels would transfer their loads to smaller vessels that
shuttle the containers to port. The Seahub project is being developed
by the Coastal Operations Institute, a Florida-based consortium that
includes federal and state agencies as well as private companies and
head of Littoral and Expeditionary Warfare Technologies at the U.S.
Navy Coastal System station in Panama City, Fla., conceived the idea.
He sees the Seahub proposal as a timely response to the shipping demands
of the North American Free Trade Agreement, which claims that north-south
trade demands will quadruple in the next 20 years. However, demands
may not be met because of the primitive transportation conditions of
the rail lines and trucking highways in Mexico. Seahub could be
a way of placing a sophisticated delivery point in places that don't
have developed shipping systems,'' he said.
doesn't believe Seahub will pose many challenges for design theory
because the station would essentially be just two or three times the
size of an oil drilling rig. However, Moritz says it creates a whole
set of interesting new hurdles for systems engineers. There are
opportunities to build in new technologies for inspecting containers
to prevent smuggling contraband,'' he says. In a Seahub
situation, one could design automated inspection systems that could
save truckers time down the line, which translates into an economic
savings.'' He suggests developing Global Positioning System
units to track individual containers from departure to arrival. Seahub
will require new cranes that can handle unloading in high seas conditions.
generation of fast shuttle ships will be needed to take the containers
efficiently to shore. Also, engineers could develop new scheduling systems
to move large volumes of goods more quickly and easily. We are
making people aware of the issues and trying to encourage academics
to think about this,'' says Moritz. He believes the Department
of Transportation and private shipping organizations would also have
an interest in developing the idea.
in Florida aims to exploit the vastness of the ocean to create a new
lifestylea floating city. The Freedom Ship is a proposal to build
a 4,320 foot long vessel, 25 stories high, that accommodates 115,000
people. The idea of the ship is to build a floating city with schools,
hospitals, and all the amenities of urban life. If built, it will be
the largest floating ship in the world, yet proponents and sponsors
don't expect any amazing technological advances in ship design
will be employed to pull it off. It might not be architecturally
beautiful, but it will be structurally sound,'' says Norm
Nixon, CEO of the Freedom Ship International.
Ship was designed by structural engineers rather than naval architects
because, Nixon says, naval architects are often too focused on efficiency
and speed, which was of little concern to his group. We gave up
speed for economics,'' he said. The boat is designed with
a barge-like square hull and constructed from heavy steel that will
be bolted rather than welded together.The bolt heads will stick
out and there will be more resistance in the water, but we don't
need to go fast, says Nixon. The Freedom Ship will travel at 10
knots and circumnavigate the globe every two years.
the so-called primitive design may be more economical, the price tag
is still a hefty $10 billion. The proponents of the idea are spending
most of their time these days selling shares in the boat. A 450-square-foot
apartment goes for around $150,000, while a 5,000- square-foot unit
sells for $8 million. With the structural design of the vessel complete,
engineers are working on internal systems such as waste, transportation,
and communication systems. Engineers say they plan to use state-of-the-art
incineration toilets to dispose of human waste, and there will be an
on-board train for on-board travel.
the big engineering hurdles was finding a way and a place to construct
the giant ship. Dry dock construction for a ship this size is not practical,
so the company secured land in Honduras to construct a staging area
where the base of the ship can be built in smaller sections. The sections
will then be put in the water in 300 x 400 foot lengths and, like high-rise
construction, the base will be used as the construction base for the
rest of the boat. Former Texas A&M mechanical engineer professor
Swicki Anderson has worked on the thermal engineering aspect of the
ship. It is feasible, says Anderson. As we see more
and more productive land mass converted to urban sprawl, there is a
greater incentive to examine this (Freedom Ship) as a human habitat.''
Anderson has worked on the thermal mechanical aspects of the ship for
the past three years. It takes a lot of thinking and head scratching
to get the first one done, but it gets easier after that.''
Busch is a freelance writer based in Sitka, Alaska. She can be reached