Safe Operation of Fishing Vessels Based Upon Continuous Measurements of Environmental Conditions and Vessel Stability

2001 ◽  
Author(s):  
Emil Aall Dahle ◽  
◽  
Gisli Viggosson ◽  
Dag Myrhaug ◽  
◽  
...  
1999 ◽  
Vol 36 (03) ◽  
pp. 171-174
Author(s):  
Hüseyin Yilmaz ◽  
Abdi Kükner

It is well known that stability is the most important safety requirement for ships. One should have some information on ship stability at the preliminary design stage in order to reduce risk. Initial stability of ships is an important criterion and can be closely evaluated in terms of form parameters and vertical center of gravity. In this study, using some sample ship data, approximate formulations are derived by means of regression analysis for the calculations expressed in terms of ship preliminary design parameters that can easily provide approximate GM calculations. Thus designers can be provided with ship stability at the preliminary design stage, and also a set of appropriate design parameters for improving vessel stability can easily be determined.


2005 ◽  
Author(s):  
John Womack ◽  
Bruce Johnson

This paper summarizes the results from the SNAME funded T&R grant titled Preliminary Development of the Next Generation of Stability Criteria for Small Fishing Boats. The principal goal of this project was to take a broad look at effects of head and following waves on the current still water based stability evaluation methods to focus the needs for future research in the development of new performance based stability criteria. The wave effects were calculated using an off the shelf naval architect software package of the type typically used in small fishing vessel stability evaluations to explore the ability of these software packages to perform cost effective meaningful stability research. The use of the off the shelf naval architect software package also allowed the authors to explore new performance based stability criteria formats that utilized software and basic concepts already available to the naval architect.


1989 ◽  
Vol 26 (02) ◽  
pp. 87-104
Author(s):  
Howard A. Chatterton ◽  
John C. Maxham

Stability is a critical element in the design and safe operation of sailing vessels. This paper discusses U.S. Coast Guard requirements for the intact stability of sailing vessels with emphasis on wind heel and dynamic stability criteria for passenger and sailing school vessels. The effects of deck edge immersion, downflooding angle, range of stability and intended route are examined in detail. The righting energy and wind velocity relationship of the U.S. Navy's small craft criteria is analyzed and applied. The Pride of Baltimore casualty is reviewed as an example of wind effects on a sailing vessel under various conditions of sail.


2003 ◽  
Vol 40 (04) ◽  
pp. 296-302
Author(s):  
John Womack

Small commercial fishing vessels are the largest, most diverse, and constantly evolving class of marine vessels in existence. Yet the methods used to evaluate their stability reflect a one size fits all approach with little improvement over the many decades since their introduction in the early 1900s. This conflict coupled with significant flaws in the methods used to convey stability guidance to the crews leads to unacceptable risks being taken and fishing vessels and their crews being lost. Improvements are needed in all areas of small commercial fishing vessel analysis: better criteria that reflect the true dynamic environment faced by the crews, better means to convey stability guidance, including the current risk of capsize to the crews, and lastly a program to teach stability and how to use the guidance provided.


1982 ◽  
Vol 26 (02) ◽  
pp. 106-116
Author(s):  
Richard L. Storch ◽  
Ibrahim Çaglayan

A thorough literature survey of research into the effect of water on deck on fishing vessel stability revealed that four predominant analysis techniques have been employed. The first, a static approach, is used to judge vessel stability by predicting the pseudo-static angle of heel, the heel angle about which the vessel rolls when water is trapped on deck. The second approach is a dynamic one in which the equation of motion in roll is written and the water on deck is treated as a roll-inducing moment. The third approach employs probabilistic analysis to determine the likelihood of having water on deck, usually presented as a function of freeboard and sea state. A hydrodynamic analysis, applied in the research of Dillingham, models the geometry of the water on deck as a function of time and inputs the resulting forces and moments as an exciting term in the roll motion equation, assuming linear motions. The hydrodynamic approach represents a significant advancement in understanding the phenomenon and is a logical point from which to initiate further research efforts.


Author(s):  
Eduardo A. Tannuri ◽  
Helio M. Morishita ◽  
Michel R. Miyazaki ◽  
Lazaro Moratelli ◽  
Rafael M. L. Madureira

The recent Pre-Salt oil fields discovered in Brazil are imposing some new logistical challenges concerning distribution in the internal and external markets. In order to reduce the demand in the on-shore terminals, the export oil could be directly transferred from the platforms to the export tankers. However, internal regulations define that the offloading operation must be carried out by DP Shuttle Tankers (ST). Due to this definition, since 1994, the DP-ST fleet has been increased, and the safety and uptime of the offloading operations are improving. The utilization of a DP-ST to navigate across the oceans for exportation is not economically advantageous, since the day-rates of those vessels are significantly higher than conventional (non-DP) STs. Hence, a possible solution is to transfer the oil from the DP-ST to the conventional ST in the offshore waters. Several alternatives were proposed, considering stationary tandem configuration, ship-to-ship or tandem with advance speed. This paper is focused on the stationary tandem configurations, considering the aid of offshore tugboats and/or monobuoys. The alternatives comprehend the conventional ST connected to the DP-ST or vice-versa, with the position being held by the DP system, a tugboat or a monobuoy. The numerical time-domain simulations were used for predicting the safety under typical environmental conditions, with crossed-bimodal sea states and sudden wave-wind changes. The relative motions of the vessels, hawser force, DP or tugboat utilization and loads on the vessels mooring equipment were verified in order to define the limiting environmental window for a safe operation, for each one of the alternatives. This comparative analysis was used to support the decision about this topic, since the advantages and problems of each solution could be identified.


2021 ◽  
Author(s):  
Mario Katsuragawa ◽  
Luiz Vianna Nonato ◽  
Francisco Luiz Vicentini Neto

Oceanography is a multidisciplinary science that deals with the physical, chemical, geological e biological aspects of the marine environment. As most of the sciences, oceanographic research relies heavily on sampling procedures, which can be rather simple, as obtaining a water sample at sea surface, or very complex, as bringing an uncontaminated sediment sample from hadal regions (up to 11,000 m deep) to the surface. Despite the sampling operation complexity, it is of primary importance the use of the adequate instrumentation, as well the expertise of the instrument operator. Ideally, the operator should have a good knowledge of the technical characteristics of the instruments themselves, as well as the correct procedures for their operation. In addition, he should be well acquainted to the ship equipment employed in the deployment, operation and retrieval of those instruments, including cables, winches and cranes. Only if these aspects are taken in account a reliable and safe operation can be attained. In this way, this guide was conceived as a basic reference for researchers in their on-board operations, although certainly being useful for a wide range of outdoor activities. It was based on the authors years of experience in field work onboard research and fishing vessels. It includes notions on nautical cables, onboard load handling equipment and hardware, basic ropework, basic net weaving and repairing and a nautical glossary.


Author(s):  
K. Ohi ◽  
M. Mizuno ◽  
T. Kasai ◽  
Y. Ohkura ◽  
K. Mizuno ◽  
...  

In recent years, with electron microscopes coming into wider use, their installation environments do not necessarily give their performance full play. Their environmental conditions include air-conditioners, magnetic fields, and vibrations. We report a jointly developed entirely new vibration isolator which is effective against the vibrations transmitted from the floor.Conventionally, large-sized vibration isolators which need the digging of a pit have been used. These vibration isolators, however, are large present problems of installation and maintenance because of their large-size.Thus, we intended to make a vibration isolator which1) eliminates the need for changing the installation room2) eliminates the need of maintenance and3) are compact in size and easily installable.


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