Page 46: of Maritime Reporter Magazine (September 2011)

FEATURE OFFSHORE WINDA new type of offshore wind founda- tion has emerged from the offshore oil fields and is rapidly gaining attention. It may be one of the most innovative and promising turbine foundation technolo-gies to come along in years. It is cer- tainly one of the most proven. heenerable ack up platfor is showing proise to be a leading contender in the Crown Estates upcoing rd round of U offshore wind proects. The jack up platform has been wellproven for more than 60 years in the harshest of ocean environments. It has been known for its ability to lift a signif- icant amount of weight far more than would be required to lift the largest off- shore turbines. Its unique design lifts the entire turbine and platform well above the waves, dramatically reducing many of the environmental loads. Designed and produced specifically for the offshore wind industry by Offshore Wind Power Systems of Texas, C, the Titan 200 carries the design credibility earned by a team who has designed jackup platforms for offshore oil and gas fields for more than 0 years. The team?s intimate familiarity with the IEC 1600- design and verification standards will ensure that industry certification of the Titan will be straight forward. Indeed, the American Bureau of Shipping has al- ready issued a letter stating that they are prepared to provide classification and statutory certification for the Titan. ABS was responsible for certifying 95 of the world?s operational jack up platforms. E ANThe Titan is an offshore jack up plat- form composed of a unique shaped hull with a diameter slightly smaller thanthe wind turbine?s rotor, standing on three legs with a lifting system. Known as a Dutch Tri-floater design, the platform cannot overturn while being towed to the installation site if any one arm begins to dip into the water, the other two arms push down to bring it back to horiontal. This inherent stabiliing feature makes the Titan an ideal platform to move tall heavy turbines around on the water. The platform is towed to the installation site with the wind turbine already com-pletely installed. Upon arrival, its legs are lowered and embedded into the seabed and its hull is elevated to provide a stable foundation capable of withstand-ing extraordinary environmental loads. A typical modern drilling jack up is capa-ble of working in the worst storm condi- tions in the world with wave heights up to 80 ft, wind speeds in excess of 100 knots and in water depths up to 500 feet. The Titan is specifically designed to lift the heaviest wind turbine in up to 00 feet of water. The installed platform will endure Category 5 storms and continue operation after the wind turbine has beeninspected. The platform is able to hold a tolerance of 0.01 degree in the horiontal plane, which means that the wind turbinewill remain within a 0.02 degree vertical tolerance during a storm. The hull is el- evated to allow storm waves as high as 60 feet to pass harmlessly beneath. The legs are pinned into the seabed at a sufficient depth to compensate for the overturning moment of its turbine load in windspeeds exceeding 0 meters per second (more than 8 knots). The Titan can be designed to meet all European and USoffshore environmental conditions. The natural frequencies of the Titan can be tuned in multiple ways, by shortening or lengthening the reach of the hull, thereare even patented methods used to fine tune the natural frequency of the platform after installation if that becomes neces-sary. DEPMEN & NSAAN The Titan can be assembled either on a dock or in a dry dock, depending onavailable boat yard capabilities near the wind farm construction site. After as- sembly and certification of the jack up platform, the turbine is fully erected onthe hull. This makes construction of the Titan platform and turbine less costly since land-based equipment is all that isemployed for final assembly. If the system is completed inside a dry46Maritime Reporter & Engineering News Foundations for the Offshore Wind Industry The Merits of Jack-Up Platforms By Wally Lafferty The Titan can be assembled either on a dock or in a dry dock