scholarly journals Using Length of Bilge Keel to Length of Waterline Ratio to Reduce Ship Rolling Motion

2018 ◽  
Vol 8 (2) ◽  
pp. 2731-2734
Author(s):  
P. K. D. N. Y. Putra ◽  
B. H. Iskandar ◽  
Y. Novita
Keyword(s):  
Good Stability ◽  
Length Ratio ◽  
Rolling Motion ◽  
Fishing Vessels ◽  
Bilge Keel ◽  
Minimum Ratio ◽  
Ship Rolling

Fishing vessels must have good stability and manoeuvrability. Hull with round bottom shape has a relatively poor rolling duration compared to other forms. Rolling duration reduction will improve the quality of stability of the ship which can be obtained with bilge keel installation. The objectives of this research are 1) to compare each parameter value on model ship by using bilge keel and 2) to determine the minimum ratio of bilge keel's length toward waterline length on the model ship which still has the ability to reduce rolling motion on the ship. The method used was giving treatment to model ship and observing its rolling motion with different lengths of bilge keel. Based on the result of the research, it can be concluded that bilge keel installation with some length ratio toward length of waterline has different results significantly, and bilge keel with length ratio 0.2 still have effective capability in reducing the rolling motion of the model ship.

Quality of Services Publishing Record of Fisheries (BPKP) in The Marine and Fisheries Office South Sumatera Province

2018 ◽  
Vol 1 (2) ◽  
pp. 25-32
Author(s):  
Galamda Israk ◽  
Slamet Widodo ◽  
Andy Alfatih
Keyword(s):  
Quality Of Service ◽  
Data Collection ◽  
Service Quality ◽  
Participant Observation ◽  
Secondary Data ◽  
Likert Scale ◽  
Quality Of Services ◽  
Fishing Vessels ◽  
Scale Assessment

ABSTRACT This study aims to determine the quality of service issuance of Proof of Registration of Fishing Vessels (BPKP) in the Department of Maritime Affairs and Fisheries of South Sumatra Province and what factors influence it. Data collection techniques used were the distribution of questionnaires to 60 respondents who were capture fisheries business actors with a Likert Scale assessment, as well as conducting unstructured interviews, non-participant observation and secondary data collection. The dimensions used are tangible, reliability, responsiveness, assurance and empathy. The value of service quality based on tangible dimensions is 4.2 or good, based on the reliability dimension is 4.1 or good, the responsiveness dimension is 4.0 or good, the guarantee dimension is 4.1 or good, and based on the empathy dimension is 4.1 or good. Of all these parameters, it was concluded that the quality of BPKP issuance services in the Department of Maritime Affairs and Fisheries of South Sumatra Province in 2016 was good with a score of 4.1. The conclusion is based on an assessment of an average of 58 respondents or 97.4% of respondents.

scholarly journals Stochastic Inverse Identification of Nonlinear Roll Damping Moment of a Ship Moving at Nonzero-Forward Speeds

2012 ◽  
Vol 2012 ◽  
pp. 1-22 ◽  
Author(s):  
S. L. Han ◽  
Takeshi Kinoshita
Keyword(s):  
Nonlinear Damping ◽  
Rolling Motion ◽  
Forward Speed ◽  
Roll Damping ◽  
Nonparametric Approach ◽  
Nonlinear Responses ◽  
Different Types ◽  
Experimental Trials ◽  
And Control ◽  
Ship Rolling

The nonlinear responses of ship rolling motion characterized by a roll damping moment are of great interest to naval architects and ocean engineers. Modeling and identification of the nonlinear damping moment are essential to incorporate the inherent nonlinearity in design, analysis, and control of a ship. A stochastic nonparametric approach for identification of nonlinear damping in the general mechanical system has been presented in the literature (Han and Kinoshits 2012). The method has been also applied to identification of the nonlinear damping moment of a ship at zero-forward speed (Han and Kinoshits 2013). In the presence of forward speed, however, the characteristic of roll damping moment of a ship is significantly changed due to the lift effect. In this paper, the stochastic inverse method is applied to identification of the nonlinear damping moment of a ship moving at nonzero-forward speed. The workability and validity of the method are verified with laboratory tests under controlled conditions. In experimental trials, two different types of ship rolling motion are considered: time-dependent transient motion and frequency-dependent periodic motion. It is shown that this method enables the inherent nonlinearity in damping moment to be estimated, including its reliability analysis.

A Stochastic Theory for Nonlinear Ship Rolling in irregular Seas

1982 ◽  
Vol 26 (04) ◽  
pp. 229-245 ◽  
Author(s):  
J. B. Roberts
Keyword(s):  
Markov Processes ◽  
Digital Simulation ◽  
Stochastic Theory ◽  
Simple Expression ◽  
Roll Angle ◽  
Rolling Motion ◽  
Approximate Theory ◽  
Averaging Techniques ◽  
Good Agreement ◽  
Ship Rolling

By a combination of averaging techniques with the theory of Markov processes, an approximate theory is developed for the rolling motion of a ship in beam waves. A simple expression is obtained for the distribution of the roll angle, and is tested by a comparison with a set of digital simulation estimates due to Dalzell. Good agreement is obtained over a realistic range of damping values.

scholarly journals Wavelet Analysis for Ship Rolling Motion of Purse Seiners in North Sulawesi, Indonesia

2012 ◽  
Vol 126 (0) ◽  
pp. 277-282
Author(s):  
Heffry Veibert DIEN ◽  
Hiroki YASUMA ◽  
Yasuzumi FUJIMORI ◽  
Nobuo KIMURA
Keyword(s):  
Wavelet Analysis ◽  
Rolling Motion ◽  
North Sulawesi ◽  
Ship Rolling

ROLLING OF TROLLING LINER ON SINJAI REGENCY

2017 ◽  
Vol 7 (2) ◽  
pp. 159 ◽  
Author(s):  
Aulia Azhar Wahab ◽  
St. Aisjah Farhum ◽  
Faisal Amir
Keyword(s):  
Good Stability ◽  
Rolling Motion ◽  
High Wave ◽  
Beam Seas

Trolling liner was a dominance used by fishermans in Sinjai Regency was made by traditional without planning before, so stability and seakeeping ability about sea condition was unknown. The research aimed to analyze the rolling motion of trolling liner in regular condition of beam seas. The research was a case study of trolling liner used by the fisherman in Sinjai.Geometry measurement vessel formwas done to get a model of trolling liner and then make a redesign as a comparedand thenmake a simulation using program Maxsurf v8.i.the result showed that the sample have a good stability. Higher rollingwas 18,168 onhigh wave -0,1971 m and lowerrollingwas -18,168 on high wave 0,1971 m,while theredesignshowed higherrollingwas 14,102 on high wave -0,1970 m and lowerrollingwas -14,102 on high wave 0.1968 m.

scholarly journals Chaos analysis of ship rolling motion in stochastic beam seas

2017 ◽  
Vol 19 (8) ◽  
pp. 6403-6412 ◽  
Author(s):  
Shenghong Li ◽  
Kangkang Wang
Keyword(s):  
Rolling Motion ◽  
Chaos Analysis ◽  
Beam Seas ◽  
Ship Rolling

A Combined Steady-State/Transient Approach to Study Very Large Amplitude Ship Rolling

1995 ◽  
Author(s):  
J. Falzarano ◽  
R. Kota ◽  
I. Esparza
Keyword(s):  
Steady State ◽  
Large Amplitude ◽  
Wave Amplitude ◽  
Practical Importance ◽  
Rolling Motion ◽  
Frequency Range ◽  
Response Curves ◽  
Type Of Behavior ◽  
Steady State Solutions ◽  
Ship Rolling

Abstract For ships, rolling motion is the most critical due to the possibility of capsizing. In a regular (periodic) sea, if no bounded steady state solutions exist, then capsizing may be imminent. Determining for exactly which wave amplitude and frequency the steady-state solutions disappear or become unstable is of great practical importance. In previous works (Falzarano, Esparza, and Taz Ul Mulk, 1994) and abstracted presentations (Falzarano, 1993), the global transient dynamics of large amplitude ship rolling motion was studied. The effect on the steady-state solutions of changing wave frequency for a fixed wave amplitudes was studied. It was shown how the in-phase and out-of-phase solutions evolve as the frequency passes through the linear natural frequency. For small wave amplitudes (external forcing) there exists a single steady-state throughout the frequency range, for moderate wave amplitudes there exists a frequency range where multiple steady state harmonic solutions exists. As the wave amplitude was increased further there existed a frequency range where no steady-state harmonic solution existed. In the present work, the very large amplitude ship rolling motion in the region where no steady-state solutions exist will be studied in more detail. Moreover, the mechanisms (bifurcations) that cause this type of behavior to evolve from more simple behavior will be studied using a combination of both frequency response curves and Poincaré maps. It is expected that global chaotic bifurcations such as those previously described (e.g., Thompson and Stewart, 1989) will be identified.

Nonlinear ship rolling motion subjected to noise excitation

2011 ◽  
Vol 1 (3) ◽  
pp. 249-261 ◽  
Author(s):  
Arada Jamnongpipatkul ◽  
Zhiyong Su ◽  
Jeffrey M. Falzarano
Keyword(s):  
Rolling Motion ◽  
Ship Rolling
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