Patent ID: 8387550
Filing Date: 2013-03-05
Classification: B63B

Abstract:
1. A semi-submersible floating platform for use in offshore applications, comprising: a semi-submersible hull structure including motion damping support columns, a pontoon structure adjoined to said motion damping support columns at a lower end thereof, and a deck structure supported at an upper end of said motion damping support columns for supporting equipment mounted thereon above the water surface; each of said motion damping support columns having an inner water trapping damper chamber of closed base or open base construction that allows natural flooding of said inner water trapping damper chamber during installation and before reaching an operating draft of said platform, and which when flooded provides hydrodynamic mass, damping, and in-water weight to said platform during operation; each said motion damping support column having an upper portion of smaller transverse cross sectional area, and a lower portion of larger transverse cross sectional area defining a stepped exterior configuration surrounding said inner water trapping damper chamber; and a plurality of smaller columns each having a cross sectional area smaller than said larger transverse cross sectional area of said support column upper portion disposed on the perimeter of each support column upper portion in adjacent relation and supported at a bottom end on a top end of said lower portion to surround said upper portion of said inner water trapping damper chamber.