On the Behaviour of a Cutter Suction Dredger and Loads on the Spud in Waves

Abstract

In the recent years, dredging operation in rough open sea is more often needed compared with the past years. As to dredging by cutter suction dredger, the situation is the same. To ensure good dredging performance in more severe wind and wave conditions, several technical problems need to be solved. In order to solve these problems at the basic design stage, it is essential to estimate hull motions and the loads on the spud or the spud carriage and on the cutter head. In this paper, the details of the behaviour of a cutter suction dredger and loads on the spud in waves are discussed. Numerical calculations and model experiments have been made to clarify relations between hull motions and the loads on the spud, and on basis of there results, reliability of estimation was evaluated. The calculated were in agreement with the experimental ones. It was therefore confirmed that numerical calculation method has a practically reliable accuracy. And this paper explains the following items in reference to the practical design applications of the 8000ps cutter suction dredgher working with spud in waves. (1) The effect of water depth on hull motions and loads on the spud (2) Results of elastic suppocted device equipped on spud keeper to decrease the loads on the spud (3) Relationship between hull motion and ground bearing forces of spud at seabed