Case Study On the Evaluation of Floating Hose Forces In a C.A.L.M. System

This paper focuses on the evaluation of the forces acting on a floating hose connected to a CALM (Catenary Anchor Leg Mooring) buoy installed in 24 meters water depth offshore Brazil. The system works as an offshore terminal for crude oil carriers. The buoy, which has the submarine hoses in a Chinese lantern pattern, was modified to include a ramp where the floating hose is laid. The system consists of the buoy, submarine hoses, mooring system, mooring hawser, a VLCC and the floating hoses. Structural and hydrodynamic analyses of the whole system were carried out to determine the cyclic loads (range vs. number of cycles) for fatigue analysis and maximum expected forces at the hose and contact forces between hose and ramp. The results are compared with allowable limits in order to check the feasibility of the system.