Noise and Vibration Level on the Training Ship "Seisui Maru"

The Training ship "Seisui Maru" was designed to reduce the noise and vibration level of each room concerned ; to make a suitable environment for the precision machines, and student training and study. After she was completed in July 1980, the noise and vibretion level was measured on the sea, measuring was carried out in the center of each room and a microphone was set on the floor at a height of 1.2～1.5m and a vibration pick-up was set directly on the floor. Consequently we have obtained the following data proving the efficiency of the sound-proofing materials ; 1) Navigating with the main engine and the dynamo engine. a) In the laboratory, the wheel house, and the student-room, the noise level was 61～66dB (A) and the vertical vibration level was 62～73dB. b) In the engine control room the noise level was 75～80dB (A) and the vertical vibration level was 65～72dB. c) The worst room (in condition) was the mess room and the chief engineer's room with the noise level at 72～81dB (A) and the vertical vibration level at 65～81dB. 2) Operating only the dynamo engine and the air-conditioner. a)In the laboratory, the wheel house,and the student-room,the noise level was 56～61dB (A) and the vretical vibration level was 50～56dB. b) In the engine control room the noise level was 76dB (A) and the vertical vibration level was 60 dB. c) The worst room ( in condition) was the galley and the chief engineer's room with the noise level at 75dB (A) and vertical vibration level at 65～67dB. 3) Operating the bowthruster. a) In the laboratory the noise level was 63～69dB (A) and the vertical vibration level was 59～62dB. b) In the student mess room the noise level was 64～77dB (A) and the vertical vibration level was 65～68dB . We also measured the noise level on the land while she was moored to the wharf. As regards the noise level outside the ship, we got the figure of 60dB (A) and less at the scene only 20 meters away from the ship. We found that the noise from the engine room is related to the layout of the room and passageways which is valuable data for the designinig of small-type vessels. * Principal items of the training ship "Seisui Maru" Mie Univercity. Gross tons : 359.31 L..B.D : 47.00× 8.4 × 4.0m Power : Main engine 1,300 ps diesel (1) Dynamo engine 360 ps diesel (2) Fishing plants : Stern trawl, Drift net, Tuna long-line etc. Marine research instruments : CTD, BT, GEK etc. Equipment : Refrigeration engine,Hydro pump unit, Control pitch propeller, Bowthruster etc