著者
小澤 宏臣 村田 航 坪川 毅彦 吉武 正湛 高品 純志
出版者
公益社団法人 日本マリンエンジニアリング学会
雑誌
マリンエンジニアリング (ISSN:13461427)
巻号頁・発行日
vol.40, no.2, pp.163-167, 2005-03-01 (Released:2010-05-31)
参考文献数
3

「ちきゅう」 (以下, 本船と記す) は, 大水深海域にて科学掘削を行う世界最大かつ最新の掘削船として, 2003年7月に船体部を三井造船 (株) 玉野事業所にて完成させ, 現在, 三菱重工業 (株) 長崎造船所にて, 掘削部の最終艤装中である.ここでは, 本船の船体部の主要部をなす自動船位保持機能について述べる.
著者
堀籠 教夫
出版者
公益社団法人 日本マリンエンジニアリング学会
雑誌
日本舶用機関学会誌 (ISSN:03883051)
巻号頁・発行日
vol.15, no.9, pp.744-751, 1980

It is not so easy to obtain the failure rate, the lifetime distribution, MTBF and so on from field data, because the field data are so called the incomplete data or the censored data consisting of time to failure for failed units where the failure and the running time are intermixed.<BR>This paper describes mainly the estimation methods and their application to the field data of marine engine system. The Weibull model adopted is a one with two parameters, i.e., the shape and scale parameter.<BR>In particular, we emphasize the estimation methods, that is, the Best Linear Estimation Method developed by N. R. Mann, the Hazard Plotting Method proposed by W. Nelson and the Maximum Likelihood Method by A. C. Cohen.<BR>Then, we illustrates examples of case studies on the censored data.<BR>Finally, we touch on the determination method of the optimal preventive maintenance on the basis of the Weibull model obtained.
著者
福岡 俊道
出版者
公益社団法人 日本マリンエンジニアリング学会
雑誌
マリンエンジニアリング (ISSN:13461427)
巻号頁・発行日
vol.48, no.6, pp.847-853, 2013-11-01 (Released:2014-11-01)
参考文献数
10
被引用文献数
1

A bolt heater is frequently applied to tighten large and critical structures with large bolts that cannot be clamped by any other means. In addition, multiple bolts can be tightened simultaneously by using the same number of bolt heaters. When bolt heaters are used for tightening large bolts, they are usually placed vertically because the target bolts are installed in the same vertical direction. In this study, the applicability of horizontally plated bolt heaters is examined to promote its broader use. It is found from tightening experiments that the bolt heater technique can be applied for bolts placed horizontally or on an inclined plane. Based on the experimental results, a guideline is proposed for the cases of bolt heaters used in the above-mentioned manner. It is also shown that the bolt heater technique can be an effective assisting method to JIS B2251, “Bolt tightening procedure for pressure boundary flanged joint assembly”.
著者
塩崎 洋 青木 太郎 清水 悦郎 伊藤 雅則
出版者
公益社団法人 日本マリンエンジニアリング学会
雑誌
マリンエンジニアリング (ISSN:13461427)
巻号頁・発行日
vol.47, no.1, pp.105-110, 2012-01-01 (Released:2013-10-26)
参考文献数
6

A snake is an amazing animal considering that it can make various motions using only its slender body. Many researches on snake-like robots have focused on ground movement. However, aquatic animals such as sea snakes and eels also move in a meandering motion. Considering these facts, the authors decided to develop an autonomous underwater snake-like robot. As an approach to this goal, a sea snake robot was made to examine the basic characteristics of propulsion. In the experiments, three axial force gauges and two cameras at different angles were set on the robot’s head. The frequency, amplitude, and phase difference which constitute the elements of meandering motion were varied, and the movement and forces acting on the robot were measured for both in-water and in-air operation. From the results of experiments, the characteristics of the propulsion force of snake motion water were discussed.
著者
乾 文雄
出版者
公益社団法人 日本マリンエンジニアリング学会
雑誌
日本舶用機関学会誌 (ISSN:03883051)
巻号頁・発行日
vol.15, no.10, pp.825-830, 1980 (Released:2010-05-31)

Recently, marine fuel quality has been deteriorating. Consequently, many engine troubles due to low quality fuel have been increasing.In this article, the present writer describes only about troubles of oil heaters caused by low quality marine fuel. According to the investigation carbonaceous deposits on the fuel side of the heater and corrosion of heat transfer pins were remarkable.Our investigation revealed that clogging troubles caused by deposits on the fuel side surface have suddenly increased since around 1977. According to the recent data in case fuel additives were added to the bunker fuel, deposit troubles have remarkably decreased. As the original material of the Sun Rod oil heater pin had been copper, corrosion sometimes occurred on the copper pin. Since the maker changed the material to aluminum, very few corrosion has occurred.Marine fuel quality will gradually further deteriorate in future, as well. Accordingly, the troubles are likely to occur more frequently.The most important thing, among other things, for the maintenance of fuel oil heaters is to develop the chemical detergent capable of cleaning up carbonaceous deposits on the heating surface. Unfortunately at present no effective detergent solving the troubles are available on the market, therefore the development of such detergent for chemical cleaning are keenly desired.