The Acceleration Frequency Measuring Equipments of the Ship in Waves

Abstract

In an endeavor to assist the scrutiny of design conditions for acceleration from statistical viewpoint, long term measurement of acceleration frequency was successively taken on M.S. "OREGON-MARU" and "MONTANA-MARU" of the Kawasaki Line between February 1960 and February 1961 in North Pacific Ocean. The acceleration frequency measuring equipment which was installed on these ships and brought about the success in the preparation of statistical distribution of acceleration was specially made for this measurement and was designed to meet the following requirements. 1. It is highly desirable that the measurement can be made automatically as much as possible, because the data for acceleration must be taken continuously for a long period. 2. As the measurement data will be voluminous, it is desirable that the equipment will analyze the result quickly and automatically. Laying special emphasis on the above two items, following equipments were made. a. Boundary displacement type magnetic recorder with its accessories which records the wave form continuously in proportion to acceleration on the magnetic tape. b. Reproducing and counting device which automatically counts the amplitude frequency of acceleration from continuous recording magnetic tape. The former was used on the ships and the latter on land.