ON THE MOTIONS OF SUCTION PIPE CONSTRUCTIONS A DYNAMIC ANALYSIS

Abstract: With the introduction of jumbo trailing suction hopper dredgers and the development of deep sea dredging equipment came suction pipe constructions and gantries of ever increasing dimensions. The implementation of submerged dredge pumps and the application of longer and greater number of pipe sections of large diameter resulted in suction pipe constructions which distinguish themselves from traditional constructions by their bigger mass and deviating mass distribution. Given the fact that these characteristics have changed significantly and are features that determine the dynamic motion behaviour of a suction pipe construction, one enters a new field concerning the dynamic behaviour of these constructions. This paper describes a mathematical model, developed at IHC Holland’s R&D institute MTI Holland in co-operation with Delft University of Technology. With this mathematical model one can perform calculations in the frequency domain to determine the eigenvalues and eigenvectors of an arbitrary suction pipe construction during the hoisting or lowering operation above the water line. These eigenvalues and eigenvectors determine the dynamic motion behaviour of the suction pipe construction. By implementing the motions of the vessel into the model it was furthermore made possible to determine th