Response Analysis of a Truss-Pontoon Semisubmersible With Heave-Plates

An offshore platform that is efficiently designed to reduce the wave excitation forces and increase the separated-flow damping could qualify as a platform operating even near its resonance. Such design could make this concept cost-effective, as well as operationally more productive with minimum downtime. The principal purpose of this paper is to describe an offshore platform design that could face the resonance efficiently. The paper applies the concept of both hydrodynamic added mass and separated-flow damping intelligently in the design of a large deepwater floating vessel on column-stabilized principle. The platform is designed to face resonance due to extreme waves and utilizes the damping to control its motion, thereby qualifying its field application. The design is justified and verified with the results of a scaled-model study in a large wave tank. The results of the correlation of theoretical study with the model test results are presented herein. A few variations of the deepwater platform concept are discussed.