3D bottom mooring line Download the model: 3D_Bottom.stask Figure 1. 3D bottom mooring line — SIMA model view 1. Description This example demonstrates how to apply a 3D seafloor read from a file in a RIFLEX model. A single chain mooring line is modelled in a water depth of 320 m, running from a fixed fairlead near the surface down to an anchor on the seabed. The line follows a catenary shape, with its lower part resting on the seabed, so the interaction between the line and the seafloor is the focus of the model. The 3D bottom geometry is imported from an external file (located in ST_3D_bottom/bottom_3d3.dat), referenced by a regular 3D bottom under Location. Contact between the line and the seafloor is handled by a spring contact model applied to all segments of all lines. The line is modelled using an axisymmetric cross section, which is the appropriate cross-section type for chain and other slender, effectively bending-free elements. Properties such as — mass, axial stiffness and hydrodynamic coefficients — are specified. The static analysis follows a load sequence applying gravity/geometry, fairlead displacement, current and seafloor friction. The dynamic analysis is a short irregular time-domain simulation driven by the current environment, intended to demonstrate the workflow rather than to produce design loads. Figure 2. 3D bottom mooring line — slender system sketch