2.1Modelling of slender structures in marinę technology 2.2RFEM in modelling the dynamics of of fshore installation 2.3Control of of fshore devices 2.4Software used in analysing the dynamics of of fshore installation 3.Description of the proposed RFEM modification 3.1The conventional formulation of RFEM 3.2Earlier modification of RFEMI 3.3Proposed modification of RFEMII 3.3.1Kinetic energy of the element 3.3.2Potential energy of the element 3.3.3Generalized forces 3.3.4Mapping of bending and torsion by sde ® 3.3.5Elongation mapping by sde 3.3.6Reactions and constraint eąuations 3.3.7Synthesis of eąuations 3.3.8Water forces 3.3.8.1Viscous resistance forces 3.3.8.2Inertial forces 3.3.8.3Buoyancy forces 3.4Eąuations of motion including the impact of the sea environment 3.5Special cases of eąuations 3.6Elimination of selected generalized coordinates, coordinate systems 3.7Description of the computer implementation of the proposed modification of RFEM II 4.Verification and validation of models and computer programs 4.1Models excluding sea environment 4.1.1Deflections of the chain line 4.1.2Shape of the rope and displacement of rope end 4.1.3Natural freąuencies of the riser 4.2Models considering the sea environment 4.2.1Shape of the rope and displacement of rope end 4.2.2Bending moment in the riser 4.2.3Periodic vibrations of the riser submerged in water 4.2.4Natural freąuencies of tensioned riser 5.Applications of models 5.1Optimization of bending moment in the riser 5.2Stabilizing the load attached to the rope 5.3Model of the Knuckle Boom crane