Marine Vehicles Design, Testing and
Fabrication
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Submersible
Pipeline Repair Vehicle
Makai
was involved in a long-term design project with Shell Development in
Houston for a large submersible pipeline repair vehicle (SPRV). Makai was chosen
for its capability in designing large, buoyancy-controlled structures. The
initial design for this remote-controlled vehicle was for 3000' depths and
payloads of 100,000 pounds. The final goals for the first vehicle were changed
to allow for considerably heavier payloads, shallower water, and deployment in
the North Sea. Makai's responsibilities for the 700-ton,
all-aluminum submersible included the ballasting, propulsion, docking,
surface handling, and vehicle structure design around the tooling and
electronics. Extensive model testing was conducted in Hawaiian waters for
surface and subsurface handling characteristics and strain tests. A model was
also taken to Marietta, Georgia, for wind tunnel testing of submerged drag
characteristics.
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High Sea State Recovery
Makai analyzed and studied the feasibility of recovering a
40-ton oil service maintenance capsule in Sea States 5 and 6 for Lockheed
Petroleum Services, Ltd. Models were built to one-twelfth scale and a system
design was successfully developed and tested.
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Submersible Launch, Recovery, & Transport Vehicle
The
Submersible Launch, Recovery, & Transport (LRT) Vehicle is a unique,
manned submersible recovery system designed by Makai Ocean Engineering. This
economical vehicle has been developed to safely and reliably launch and
recover manned submersibles in rough seas and to provide a platform for their
speedy transport over long, open ocean distances.
The
LRT is a twin-hulled, submersible platform upon which a submarine is
placed and secured. It is towed on the surface by a support vessel to a
selected dive site. The LRT and the submarine are both submerged under the
control of the diver pilot and then accurately maintained in a stable hover at
a depth of 50-60'. With the assistance of the deck crew, the submarine
is released from the LRT and begins its dive and the LRT returns to the
surface.
Makai's
first LRT was designed to transport and deploy the STAR II research submarine
in rough Hawaiian waters. This LRT was operated for 12 years,
with over 1400 successful dives, by the Hawaii Undersea Research Laboratory of
Hawaii.
A
larger LRT was designed, fabricated and ABS certified to
support the 13 ton PISCES V manned submersible for the University of Hawaii.
After a series of successful tests, this LRT was used for regular operations.
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From the viewpoint of the submarine operator, he sees the
submerged LRT hovering in the depths much like an airplane pilot does when
approaching an aircraft carrier, but with a far easier and safer landing to
perform. The submarine pilot guides his vessel onto the LRT and, with the
assistance of scuba divers, it is secured to the LRT and then the LRT
surfaces. A launch or recovery sequence will take from 5 to 10 minutes.
The
LRT is a highly reliable, safe, and inexpensive method of handling a massive,
awkward and delicate vehicle in rough seas. Mating of the two vehicles occurs
below the surface where the LRT and the submersible's wave responses are
nearly identical, the relative motion is extremely small and safe. The LRT
configuration provides a high degree of stability both below water, on the
surface, and through the interface.
The ABS-certified aluminum LRT was also economical since no large support vessel
with a large crane was required.
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Salvage System
Makai
consulted for a Great Lakes diving company, Deep Diving Systems, for the salvage
of a 700-ton schooner that sank in 1911. A design for a combination dry
dock and salvage vehicle was provided, utilizing scrap steel tank cars.
Underwater
Oxygen Extraction Vehicle
Makai
has worked closely with researchers from Aquanautics Corporation to evaluate the
potential of developing a proprietary system for the extraction of
dissolved oxygen from seawater for use in submersible vehicle power systems.
This was a U.S. Navy DARPA funded project.
It had as its goal, designing, constructing and demonstrating a
self-sufficient, oxygen extraction submersible vehicle. Makai was
responsible for the ocean engineering on the project, fabrication of the vehicle
and vehicle testing at Makai's ocean facilities
Model
Testing
Although
this aspect of work has been discussed relative to specific contracts, it
deserves special emphasis relative to Makai's overall capabilities.
Makai
has realized the limitations of wave tank testing, especially for high sea state
systems and systems which must be tested underway at various angles to the
waves. The basic problems with wave tanks are cost, the limited size of waves
which can be generated and the distortion of these waves due to shallow tank
depths available. To develop a representative deep ocean wave, the water depth
should be ten times the wave height. We have, therefore, developed considerable
experience in economically testing large, scale models both underway and
stationary in deep water and can test in bi-directional and/or breaking
waves.
In
addition, our unique location at the Makai Research Pier allows for convenient
testing in actual ocean conditions. Both surface and underwater testing can be
done either in our harbor or offshore.
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For more information, contact:
makai@makai.com
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