• Korean Journal of Fisheries and Aquatic Sciences
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• v.8 no.4
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• pp.202-207
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• 1975

During the term of June, 7 to August 11, the noises in the maine engine room in terms of the r. p. m. of the Pung-Yang Ho (4,500 H. P.), the Chuk-Yang Ho (3,800 H. P.), the Dong-Bang Ho (3,000 H. P.), the Oh-Dae San Ho (2,690 H, P.), the Kwan-Ak-San Ho (1,000 H. P.) and the Back-Kyung Ho (850 H. P.) (Refer to Table 1) were measured with the use of sound level meter, which has measuring range 37-140 dB and the results obtained are as follows : 1. Capacity of the engine room becomes large according to the total H. P. of the main engine, but the vessels are using of a type of engine, i.e., 6 cylinder, and thus the noise, pressure has shown a tendency to become lower except Kwan-Ak-San Ho, Chuk-Yang Ho and Dong Bang Ho where the noise pressure was higher by 3 dB than curve of mean value. 2. The maximum noise pressure appeared even before the main engine reached the maximum r. p. m. and while the percentage of the r. p. m. varied depending on the vessel, the maximum noise appeared at around the $67-75\%$ of the r. p. m. 3. The maximum of noise pressure in the respective engine room ranged between 93.5-105 dB while it was between 72-81 dB at the fish process room in the stern trawl vessel where the oral communications were possible.

• Proceedings of KOSOMES biannual meeting
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• 2006.11a
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• pp.125-129
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• 2006

It is very important to remove the noise levels made by an electric home appliance and machines they are located in the auditory region. The noise of ship engine room is known as it is not easy to lower so the working environment of the engine room is the worst condition because the improvement for the noise seemed insignificant and the hearing loss is occurred. As the monitoring equipment and an intelligent control system are improved rapidly the main engine of the ship can be enclosed with an acoustic barrier and any other absorbtion equipment. In this study, the sound absorbtion barrier is experimentally researched by change the volume and the length of the neck for the Helmholtz resonator as the resonator can absorb the noise effectively.

• Proceedings of KOSOMES biannual meeting
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• 2006.05a
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• pp.207-212
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• 2006

The noise levels on board ship recognized at Europe in the early 1970s and the noise regulations on board ship began to put in a statutory form. After that, in 1982 "International Code on Noise Levels on Board Ships" adopted by IMO and it became standard to the newly built ship and remain so to this day. Especially, the ship engine room, which have huge main engine and various kinds of subsidiary machines, is under an extremely loud condition and so the worker who works in it is easy to lose his hearing. Recently, each nation regulates the allowable noise exposure time by law to protect the industrial employee from the occupational hardness of hearing. In our country, the allowable noise exposure time is regulated by the labor standard law but the international provisions regulated by IMO have been applied in case of the ship engine room. In this paper, the cabin's noise levels of cargo-passenger ships plies south-west coast line were investigated.

• Journal of the Korean Society of Marine Environment & Safety
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• v.12 no.3 s.26
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• pp.193-199
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• 2006

The noise levels on board ship recognized at Europe in the early 1970s and the noise regulations on the ship began to put in a statutory form. After that, in 1982 'International Code on Noise Levels on Board Ships' adopted by IMO and it became a standards to the newly built ship and it remains up to recently. Especially, the ship engine room, which have huge main engine and various kinds of subsidiary machines, is under an extremely loud condition and so the worker who works in it is easy to lose his hearing. Recently, each nation regulates the allowable noise exposure time by law to protect the industrial employee from the occupational hardness of hearing. In our country, the allowable noise exposure time is regulated by the labor. standard law but the international provisions regulated by IMO have been applied in case of the ship engine room. In this paper, the cabin's noise levels of cargo-passenger ships plies south-west coast line were investigated.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.6
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• pp.875-882
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• 2021

To minimize occupational noise induced hearing loss, it is recommended that workers should not be exposed to noise levels exceeding 85 dBA for over 8 h. In the present study, noise exposure levels were measured for seven workers based on their tasks on a training ship. The A-weighted noise exposure level (L_ex,24h) was measured by taking into account the A-weighted equivalent continuous sound level (L_Aeq,i), duration (h) and noise contribution (L_ex,24h,i) from the workers' locations. Results are thus obtained for different job categories as follows: officer group L_ex,24h=56.1 dB, navigation crew L_ex,24h=58.9 dB, navigation cadet L_ex,24h=62.0 dB, ship's cook L_ex,24h=64.3 dB, engine cadet L_ex,24h=91.1 dB, engineer L_ex,24h=91.1 dB, and engine crew L_ex,24h=95.1 dB. It was determined that the engineers, engine crews, and engine cadets in charge of machinery must wear hearing protection devices. By wearing hearing protection devices when working in highly noisy engine rooms, it is estimated that the noise expose levels could be reduced by the following amounts: engineer L_ex,24h=23.1 dB, engine Crew L_ex,24h=24.4 dB, and engine cadet L_ex,24h=21.5 dB. Moreover, if the no. 2 lecture room and mess room bottom plates in the cadets accommodations were improved to the 64 mm A-60-class floating plates, then further reductions are possible as follows: navigation cadet L_ex,24h=4.3 dB and engine cadet L_ex,24h=1.8 dB.

• Proceedings of KOSOMES biannual meeting
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• 2007.05a
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• pp.109-113
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• 2007

Yacht have an high powered main engine relatively light hull, so the noise generated from the engine have a bad influence upon the crew and passenger. Recently, cruise yacht is made an attempt by domestic production skill, however the insulation skill of the noise made by the main engine is not satisfy the real purchasing power of the buyer. Like this, yacht cabin's noise level is becoming the barometer to decide the purchase. the method to insufficient. However, if we use the skill of the monitoring equipment and the genetic algorithm system, the circumference of the main engine can be enclosed by an high quality absorbtion wall and the noise levels of the cabins are improved. In this study, the sound absorbtion barrier is experimentally researched by change the volume and the length of the neck for the Helmholtz resonator as the resonator can absorb the noise effectively.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.6
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• pp.620-627
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• 2023

Ship noise is one of the important factors for the living and health of seafarers, and ef orts to reduce ship noise are actively underway. There are two methods of noise reduction: passive noise Control (PNC) and active noise control (ANC). Unlike cars and airplanes, ANC is not widely used for noise reduction on ships. This study aimed to reduce the noise generated in the engine room by using soundproof panels and high-frequency vibration generators, as well as active noise control (ANC). For this purpose, an experimental model was made using an acrylic box, and the noise reduction effect was measured under four conditions. The experimental results are as follows: First, the soundproof panel had a noise reduction effect in all ranges from 55 dB to 85 dB. In the case of using a high-frequency vibration generator, there was no ef ect in the low noise range such as 55 dB(A), but there was a noise reduction effect in the high noise range such as 70.8 dB(A) and 85 dB(A).Second, when the soundproof panel and the high-frequency vibration generator were used simultaneously, the noise reduction ef ect was up to -2.2 dB(A). The results of this experiment were obtained from an experimental model made of acrylic, and they may be different from actual ships made of steel plate. In future studies, we plan to experiment using iron plate (considering the material, thickness, and structure) used in actual ships. We hope that this study will help to improve the living environment and health of seafarers on ships.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.1
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• pp.42-49
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• 2008

Most of vessels are not evaluated for their vibration and noise effects to human body. The vibration and noise generated by engine and auxiliary machine in vessel is a negative element for seamen. Therefore, in this paper, the diagnosis and evaluation of vibration and noise from vessel is accomplished by a shipbuilding corporation. The vibration and noise transferred from engine room and auxiliary machine was measured during the steady-state operation, and the vibration and noise map of vessel was made. Also, in order to evaluate the ship environment for human, the diagnosis is carried out on the base of measurement results.

• Journal of Power System Engineering
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• v.3 no.3
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• pp.97-103
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• 1999

As the noise of ship engine room is too loud, the engineer who works in a ship engine-room has the trouble of hearing. In this paper deals the investigation of the noise of ship engine room and cabins with the internationally allowable noise exposure level and noise exposure time. Recently, the problem of engine-room noise is more serious because of shipowner wants to make small number and larger size of cylinder. Therefore, engineers work in a ship engine-room for a long time have the trouble of hearing when they are exposed the high noise level. In this study, two kinds of vessels were used to investigate the noise of engine room, engine-control room, bridge, offices and cabins. As criteria of sound levels, A-weighted sound pressure level and octave band pressure level were used.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.8 no.3
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• pp.127-132
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• 1975

This is an experimental study that aimed to find out a possible relationships between the noise of the ship and the intelligent quotient, and the creativity of the crew member during June 5, to August 24, 1975. The experiment was carried out on the university training ship, the Oh-Bae-San Ho(1,126 tons), and the Kwan-Ak-San Ho (243 tons) and the training ship Baek-Kyung Ho (380 tons) of Je-ju College, where the total number of 144 students engaged on their tasks of practical exercise. And the following results were obtained : The decreases of I.Q. was evident as compared to the score obtained at the class room; soon after the embarking of the ship, the students on the deck decreased the score by $7\%$ of what they obtained at the class room while the students in the engine room decreased by $13\%$. The I.Q. was regaining the normal state after three days of embarking seemingly showing the fact that the students became adapted to the noise of the ship, but no remarkable improvement was visible during the period of 3 days to 35 days on the ship. One of the remarkable fact that had not been expected was that the problems for audio discernment was much easily solved in the midst of noise that made oral communication impossible (102 dB) than in the place of noise where conversation was possible(67 dB).