Matao Takagi

Design of mooring system of vessels inside breakwater

Abstract A method of simulation calculation for a mooring system of vessels inside a breakwater is illustrated. Using a simulation program based on the above method, a test design for a mooring system for oil-storage vessels of total 5.6 million kiloliters was conducted. In order to obtain data for the simulation program, various experiments, such as wind tunnel tests to test wind resistance, and wave tank tests to test the waves transmitted through or over the breakwater, and the motions of vessels inside the breakwater due to waves, were conducted. Some proposals concerning design criteria and safety factors are presented. Finally, the results of the test design under estimated sea and weather conditions are shown, and the design is concluded to be both technically and economically feasible.

On the Shape of the Wall Ventilator

This report is to do with the experimental results of the performance of the wall ventilator conducted by the present author. As the results of these experiments, the ventilation mechanism of the wall ventilator was made clearer, and it became evident, moreover, that to increase the ventilation efficiency, special attention should be given to the following three points : 1) As the ventilation action depends largely upon the aft pipe, it is highly desirable to design the aft pipe as large as possible.2) Moreover, the ventilation efficiency has much to do with the shape of the passage from the main pipe to the aft pipe, and accordingly, it is important to make it hydrodynamically smooth.3) It is highly desirable to make the diameter ratio of the fore pipe entrance to the aft pip moderate. In case when the ratio is excessively large, the fore pipe often disturbes the ventilation action due to the aft pipe only.