Titan Wind Turbine Platform
By James E. Ingle P.E.
Wind turbine foundations using piles driven into the ocean floor have been used to support wind
turbines in shallow waters but these structures present many problems as the water depth
increases. The Titan Wind Turbine Platform was created to economically support a single wind
turbine in water depths greater than approximately six fathoms (48 feet). By using proven design
methods for designing jack-up drilling rigs and using newly patented jacking technology the Titan
Wind Turbine Platform was designed to incorporate many advantages.
Since the Titan Wind Turbine Platform is capable of floating with the wind turbine installed on the
platform and the legs retracted, the platform and wind turbine may be completely assembled and
tested at the shipyard where the unit has been constructed. Then it can be towed to the
predetermined location and put into service. During the transportation phase the platform must act as
a barge or ship and must be designed to have adequate stability while floating with the legs in the
The shape of the hull is designed to provide stability by having the floatation compartments located at
the ends of each leg of the “Y” shaped hull. The trusses near the center of the platform provide an
economical structure to connect the buoyancy compartments and support the wind turbine. The size
of the hull is designed to provide sufficient righting arm for stability. Transporting the platform during
high waves and wind requires the metacentric height of the floating platform with the wind turbine to
be higher than the center of gravity of the unit, therefore providing sufficient righting arm moments to
keep the platform upright.
After transporting the platform to the desired location, the footings are flooded and the legs are
lowered to the sea floor. The platform is then raised a few feet above the water surface and the
preload tanks filled with water. This preloading of the footings provides a vertical force on the footings
which is greater than any load generated by wind on the platform and wind turbine, waves and
current. The footings are spread apart to provide sufficient stability from overturning of the platform
during high wind, wave and current. When the footings have been preloaded, the fins on the bottom of
the footings are immersed into the sea floor. These fins provide resisting forces to keep the platform
from moving laterally.
The shape and size of the footings is very important. If the footings are too small, the footings will
penetrate too far into weaker soils. If the footings are too large, the footings will not penetrate into the
sea floor far enough to provide sufficient lateral resistance to keep the platform stationary. The size of
the footings for the Titan Wind Turbine Platform has been determined from experience in designing
footings for jack-up drilling rigs and is the proper size to function properly in most sea floor soils. After
preloading the footings, the platform is raised to the desired elevation. This elevation places the
bottom of the hull above any wave height for this location. The location of the footings and the weight
of the platform and turbine provide sufficient stabilizing forces against the overturning forces to keep
the platform from overturning.
One of the advantages of the Titan Wind Turbine Platform is that it can be moved to another site. Or, if
the wind turbine requires major repairs the legs of the platform may be raised and the platform may
be towed to a dock or repair yard. After the necessary repairs are made, the platform can be returned
to its previous location or towed to another location. Therefore, expensive crane barges to facilitate
repairs at sea are eliminated.
Wind turbine locations in shallow water are usually close to land and highly visible from land. The
Titan Wind Turbine Platform is designed for deeper water depths and is intended to be located
further out to sea. Therefore, they are less visible to people on shore. If the platform is placed about
six miles from shore the curvature of the earth hides the platform and the tips of the wind turbine
blades would be practically invisible.
The hull design shall conform to the standards of the American Bureau of Shipping and, as
demonstrated by jack-up drilling rigs, have a life span of over twenty-five years. The life span of wind
turbines is reported to be approximately the same length of time making the design compatible.
Since energy from wind turbines is a renewable power source, and because fossil fuels are
becoming more expensive to obtain, energy from wind turbines will be in greater demand,. The Titan
Wind Turbine Platform has many advantages over shallow water wind turbine platforms and can be
located on larger areas of the earth.
|2004 ASME-IPTI / OTC Woelfel Award for Mechanical Design
Jim Ingle (R) , Douglas Hines (CTR)
|Offshore Wind Power Systems
of Texas llc