INTRODUCING OPERATIONAL INFORMATION INTO EARLY STAGE SHIP DESIGN USING QUEUEING NETWORKS

During the early stages of ship design a set of requirements needs to be identified, accounting for financial and technical feasibility, and operational effectiveness. This process of requirements elucidation creates a need for information regarding various design alternatives and their effect on the feasibility and effectiveness of the design requirements. When one considers internal layout and process driven ships, ships where the arrangement of spaces has a strong influence on the effectiveness of the ship's operational processes, a gap in available methods has been identified. This paper proposes a method based on queueing networks that allows a naval architect to study the effects of different arrangements on the execution of various sets of operational processes. Using this model a better understanding of the interaction between the ship's arrangement and its operational processes can be obtained. This understanding can improve the requirements elucidation process and can lead to the development of better design requirements.

ENABLING TECHNOLOGY AND THE NAVAL ARCHITECT 1860-2010

Enabling technology permits the naval architect to do more with fewer resources, increasing output, decreasing cost and improving productivity, with the resulting benefits being widely distributed in a worldwide economy. For example a bulk carrier’s energy consumption per ton-mile today is less than 3% of what it was a century and half ago – due to more efficient machinery, larger hulls with lower resistance per ton and improved propulsive efficiency, yet with higher speed and shorter port times.

ENABLING TECHNOLOGY AND THE NAVAL ARCHITECT 1860-2010

I have a brief comment to contribute: “This is a thorough review of the technical changes over the last 150 years in the Marine Sector. Even more interesting the author has linked these with the changing market and business drivers over that period. It also illustrates how the aggregation of all the individual changes represent several revolutions in the sector. Can I ask the author to now wind the story forwards and give his view of the future and what the marriage of “Technology Push” and “Market Pull” is likely to hold in store for the next 150 years. However disconcerting it might seem - the rate of change will not stop – the opportunities are legion”.

150 YEARS OF SHIP DESIGN

My comments are aimed in three directions: Where is the role of the naval architect heading? Are the students of today sufficiently aware of the achievements of their predecessors to learn from them? Is it appropriate that the public at large takes the capability of modern shipping for granted, if not how do we educate?

Status and needs for ice tank testing in a changing climate

150 years ago, the first modern icebreaker in the world was designed by the naval architect Carl Ferdinand Steinhaus and built for purpose of removing ice barriers on the river Elbe in Hamburg, Germany. No model tests were performed at that time. Later, in the first half of the 20th century, “model tests” for ships were carried out in natural ice on lakes. In the 1950th the first-generation ice model basins were put in operation and ice model testing became a standard method in the icebreaker design process. This paper discusses the influence of the economic and environmental development in arctic regions, driven by shipping and offshore activities in environmental changing Arctic Waters, on the ice model basin design, equipment and testing methods. The developments will be presented with examples from The Hamburg Ship Model Basin (HSVA). To complete the overview, an outlook to future trends is attempted.

Studi Karakteristik Stabilitas dan Konstruksi Kapal Berbahan High Density Polyethylene (HDPE)

The development of fishing and marine tourism requires the support of naval architecture, especially in small boat. The use of wood as the main material for shipbuilding has recently become a problem considering the decreasing availability of wood, while the use of fiber is classified as less environmentally friendly because it uses chemical resin and difficult to repair when it breaks and cannot be recycled. The aim of this research is to design the High-Density Polyethylene (HDPE) boat. The design was carried out by using naval architect design software. The stability of boat was calculated by using three loading conditions such as when leaving the port, in the sea and when returning to the port. The International Maritime Organization (IMO) safety criteria was using to evaluation of boat stability where the three loading conditions have met the IMO standard. The construction of HDPE boat was carried out by using DNV rules.

Design Errors in Ship Design

There is a problem in coping with design errors in ship design. Ships are generally very large and often very complex. Yet, we rarely invest in full-scale prototypes so design errors are frequently revealed once ships are at sea and certain errors can be catastrophic, others lead to many ships having shortened useful lives. The paper starts by considering the nature of design errors and failures in large-scale engineering enterprises. This is followed by looking briefly at some lessons from maritime history concerning how design errors arise and can even lead to ships sinking. A specific well-documented case of calculation error in sizing a new ship design is reviewed and lessons drawn. The relevance of general approaches to avoiding engineering errors and ever-greater emphasis on risk mitigation procedures and applying safety regimes alongside ethical guidance is reviewed. The changing nature of ship design practice is discussed, with ship designers between the horns of the dilemma of ever greater ability provided by computer driven precision and the demands for their designs to be seen to perform effectively in an increasingly uncertain and complex world. Final thoughts consider the basis for judging what might be good or bad ship designs, how errors can be addressed, and the ultimate safety role of the naval architect as the overall designer of complex vessels.

Introducing Operational Information into Early Stage Ship Design Using Queuing Networks

During the early stages of ship design a set of requirements needs to be identified, accounting for financial and technical feasibility, and operational effectiveness. This process of requirements elucidation creates a need for information regarding various design alternatives and their effect on the feasibility and effectiveness of the design requirements. When one considers internal layout and process driven ships, ships where the arrangement of spaces has a strong influence on the effectiveness of the ship's operational processes, a gap in available methods has been identified. This paper proposes a method based on queueing networks that allows a naval architect to study the effects of different arrangements on the execution of various sets of operational processes. Using this model a better understanding of the interaction between the ship's arrangement and its operational processes can be obtained. This understanding can improve the requirements elucidation process and can lead to the development of better design requirements.

Loading Conditions for Exposed-Waters Towing Vessels Regulated under Subchapter M

A set of five vessel loading conditions was developed for exposed-waters towing vessels in support of compliance with applicable stability regulations invoked under the U.S. Code of Federal Regulations (CFR) Title 46, Subchapter M. These loading conditions are envisioned as a starting framework for the naval architect or third-party organization when pursuing a U.S. Coast Guard stability letter with the fewest operational restrictions. These conditions do not represent required operational scenarios. For each loading condition, variable loads based on both tank location and tank contents were specified with the goal of encouraging conservative stability evaluations, while maintaining a level of realism to the resulting vessel attitude at each condition. Use of these developed loading conditions as a replacement for the nearly forty-year-old McGowan and Meyer conditions is anticipated. Using 3D models and General HydroStatics stability software, three vessels representative of modern exposed-waters towing vessels, but designed before the enactment of Subchapter M, were tested against 46 CFR Subchapter S stability criteria at each loading condition. Results of the analysis are presented for each vessel and for each applicable Subchapter S criterion. As expected, vessels not designed for Subchapter M/Subchapter S stability regulations can have trouble passing using the proposed loading conditions. The authors experimented with simple changes to the tank geometry of these pre-Subchapter M vessels, creating compliance with nearly all stability criteria for all loading conditions. Based on relevant literature and the results of this work, it is recommended that, for conservatism, the free-to-trim method be used for stability analysis regardless of the loading conditions applied. It is recommended that if an exposed-waters towing vessel passes the applicable Subchapter S stability criteria using the loading conditions developed in this work, then the vessel should be considered for a stability letter with minimal operational restrictions.