Patent ID: 6821055
Filing Date: 2004-11-23
Classification: B63B,E21B,F16L

Abstract:
A marine buoyancy unit for mounting upon a subsea riser, the unit having a longitudinal axis and comprising at least two complementary sections which are separable from one another along an axial plane, the sections being adapted to be joined together around the riser, forming when so joined an internal cavity which receives the riser, the sections being composed of synthetic buoyant plastic material and each having a reinforcement layer disposed within the buoyant plastic material close to an outermost surface thereof remote from the cavity, the reinforcement layer comprising high strength fibers which extend longitudinally of the buoyancy unit and are embedded in and mechanically locked into place within the buoyant plastic material by not tightly bonded to it, in order to allow limited axial movement in the event of fracture of the buoyancy unit, whereby the reinforcement layer serves to maintain residual structural integrity following fracture of the buoyancy unit.