We evaluated the safety of two moored ships in the port of Shimizu against the Tokai earthquake tsunami based on the numerical simulations. We first carried out the tsunami simulation and obtained the tsunami wave profiles at two berths in the target port. And then we performed the ship motion simulations by using the tsunami waves as the external forces. The main results are: 1) The surging is the significant motion of the moored ship against the tsunami, 2) The tensions of the spring and breast lines are larger than those of the head and stern lines, 3) The larger moored ship moves widely and influences the mooring system, and 4) The moored ships and mooring systems are safe against the tsunami.

We evaluated the safety of four moored ships in the port of Shimizu against the Tokai earthquake tsunami based on the numerical simulations. We first carried out the tsunami simulation and obtained the tsunami wave profiles at four berths in the target port. And then we performed the ship motion simulations by using the tsunami waves as the external forces. The main results are: 1) The surging is the significant motion of the moored ship because the tsunami flows along the quay, 2) The larger moored ship moves widely and influences the mooring system because its natural period for surging is closer to the dominant period of the tsunami, and 3) The mooring systems for the large ships are relatively unsafe against the tsunami.

We studied the most effective mooring method of a ship against a tsunami based on the numerical simulations. First, we set the ordinary mooring method and four mooring methods proposed as the countermeasures against the tsunami. And then, we performed the ship motion simulations by using the tsunami waves as the external forces and evaluated these countermeasures. The main results are: 1) The surging is the significant motion of the moored ship because the tsunami flows along the quay, 2) Although the motions of the ship becomes large when we set the mooring ropes long, we can reduce the effects on the mooring system (the mooring ropes and fenders), and 3) The method that the mooring ropes are set long is the most effective mooring method against the tsunami.

It is advisable for moored ships in ports to be evacuated outside ports in case of a major tsunami. However, all the ships can not always evacuate rapidly because the waterway is crowded with evacuating ships. Then, ships may be damaged by the tsunami. Although the tsunami impact on the moored ship has been well studied, the influence of the tsunami incident angle has not been studied so far. In this study, we conducted the model experiment which is considered the incident angle of tsunamis, in order to study the characteristics of the ship motion and the tsunami impact on the mooring facilities. And moreover, we performed simulation of the ship motion to compare the results of experiments. Consequently, it was able to confirm the validity of the evaluation method for tsunami force.