Model experiments on the mooring of large tanker to offshore dolphin (2)

Abstract

We had reported in the previous paper on the statical conditions (in case of strong wind). This paper is the report of experiments on the dynamical conditions. Equipments of experiments, model ship, ship's mooring arrangements (A and B type), water depth are as same as in the previous paper. Cases of experiments on wind and waves are as follows: Wind velocity 35m/sec in actual ship [table] Some results of this experiment are as follows: 1) Periods of fluctuation of tensions of mooring ropes and loads on dolphins mostly equivalent to periods of waves. 2) Ships motion, tensions of ropes and loads on dolphin are mainly effected by wave length and they become larger as length of wave grows longer. When the length of wave is the same, they become larger as height of wave grows higher. 3) We can not moored ships safely when the length of wave is more than one third of ship's length. 4) When a berth is affected by waves, it is necessary that the ship is moored parallel to the direction of wave. 5) Mooring in waves, we can not say certainly that it is better to keep deep draft. When the ship is moored broadside to waves, loads on dolphin are larger when draft of ship is deeper. 6) When length of wave is smaller than one third of ship's length, B-type method of mooring is better than A-type. But length of wave is larger, A-type is better.