EXAMPLE 2: SYNTHESISING FROM DIFFERENT SOURCES
The students who completed this task were 2nd year naval architecture and marine engineering students.

TOPIC:  Ship design

TASK DESCRIPTION:

Using information only from the excerpts provided, write a paragraph of 200 words (not less than 160 and not more than 230) discussing the topic "Ship Design".

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Remember that you need to:

• Use information from all sources.

• Cite your sources appropriately.

• Use your own words! You must not plagiarise!

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Excerpt 1

Computer-aided design, also of ships, claims to use computers only as an aid in design decisions. Thus the human designer remains responsible for posing reasonable and sometimes creative design problem formulations and for critically reviewing the results. Ship design remains a human task supported by computers, even if certain standardized subtasks are performed by computer almost automatically. But the policy of human overall responsibility has been maintained throughout the history of CASD.

The developments of the last five decades in CASD have had a deep and lasting influence on the methodology of ship design. Design and computing have mutually served as cause and effect of these changes in a close interactive relationship. The main benefits have accrued to the substance of the design process. The economy and safety of the ship have remained the most important objectives of ship design. Under the influence of the systems analysis approach both have become more quantifiable, more rational, more transparent. Methodologies for modeling random processes have far advanced and have been fully incorporated in ship design, most notably in assessing the effects of the random seaway on ship motions and sea loads as well as in stochastic models of risks of ship operations in accidents and similar hazards. The equivalence of or at least the deep affinity between design and optimization have been fully understood and accepted. The unifying perspective of design being viewed as an optimization challenge today is fully recognized. A great multitude of design problems can be modeled, which provides advantages in modeling, in problem solving and in understanding. The wealth of computer methods for simulation and visualization, as in Simulation-Based Design, has much enriched the feedback from the computer to the designer. Finally, in complex ship design applications the number of free variables and parameters may become overwhelming, even on large computers, so that the old art of problem decomposition, i.e., stagewise problem solving, is due for renewed high respect. Techniques for stagewise optimization are available, their application will not only reduce computing effort, but also benefit the clarity of problem and solution structure. This potential is not always consciously exploited [1].

 

Excerpt 2

The foundation of ships’ design is a combination of art, technology, and commercial purpose. The latest technologies concerning the equipment used for navigation, propulsion, and cargo handling form a strong influence on the final build. The multitude of cargoes carried by sea increases at great speed, and this necessitates the building of a more advanced ship design, more frequently. It is difficult to deal with the complexity of the foregoing, but the nature of man is such that he will always strive to find a solution to the problems at hand. A solution comes along sooner rather than later, and this triggers a demand for an even better product. This necessitates that the process starts all over again, but we must not forget that a successful progress brings greater rewards. Every commercial vessel is the servant of the most international of all industries, shipping. This industry was born in the depths of the most forgotten antiquity, and its purpose always was to convey cargoes and passengers. This tradition continues today, and this is where the ship’s commercial life belongs [2].

 

Excerpt 3

In ship design it is often necessary to classify the hulls and to find relationships between forms and their properties, especially the hydrodynamic properties. The coefficients of form are the most important means of achieving this. By their definition, the coefficients of form are non-dimensional numbers [3].

 

Excerpt 4

Design is a process of synthesis bringing together a wide range of disciplines and analysis methods. In the past, ship design was a process of evolution, the starting point for a new design being a type ship to which changes were made. With modern analysis tools and powerful computers, the naval architect can be more innovative. Ships, however, are complex and their design must be approached in a methodical manner. There are no prototypes so the designer must ‘get it right’ first time. There are three distinct phases – concept, contract and detail design. It is in the concept phase that the designer will establish the broad characteristics of the design in consultation with the owner. The actual design process within each phase varies with the type of ship and how novel it is. One approach is to regard the ship as possessing certain capabilities and attributes which confer upon it the ability to float, move and trade – the three key functions. Everything in the ship has a part to play and the design configuration is key to the development of a good design. Also an understanding of the relationships between equipment and systems, enabling them to contribute to the functions, is important. Embedded within the design process are assessments of the ship’s characteristics such as stability, strength, powering, manoeuvrability and motions. The design must be cost-effective, require minimum manning, be available when needed and not be unduly vulnerable. The safety of the ship, the people on board and the environment in which it sails are all important [4].

 

Excerpt 5

Ship design and, by inference, ship structural design, is iterative in nature (Figure 9.22). This is specifically derived for preliminary design purposes when the ship framing on the decks and bottom is longitudinal in nature (see Section 9.3.4.5(c)); it typifies one aspect of the more all-inclusive process of overall ship design and is therefore a spiral within spirals. Inferences to be drawn from the illustration are that among the interlocking constraints which must be satisfied, albeit in harmony with each other, the web frame and longitudinal spacings are tentatively set as initial conditions on which the final, optimized design is to be based. Other optimized designs for varying frame spacings could also be investigated [5].

 

References

[1] Nowacki, H., 2010, “Five decades of Computer-Aided Ship Design,” Computer-Aided Design, 42, pp. 956-969.

 

[2] Karanassos,H. A., 2016, Commercial Ship Surveying: On/Off-Hire Condition Surveys and Bunker Surveys, Butterworth-Heinemann, Amsterdam.

 

[3] Biran, A. and López-Pulido, R., 2013, Ship Hydrostatics and Stability, 2nd ed., Butterworth-Heinemann, Oxford.

 

[4] Tupper, E. C., 2013, Introduction to Naval Architecture, 5th ed., Butterworth-Heinemann, Amsterdam.

 

[5] Molland, A. M. (ed.), 2008, The Maritime Engineering Reference Book: A Guide to Ship Design, Construction and Operation, Butterworth-Heinemann, Amsterdam.

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STUDENT REPLY 1

Since the beginning of maritime exploration ship design has been a demanding process,in which ingenuity and technology merge with commercial purposes [1]. The complexity of the process,and the important criteria that are present are an indicator that the design will not be a straight line, but a spiral, an iterative process.In this case the multitude of constraints that exist between the ships structural components forego constant change,one affecting the other [2]. In this study, the coefficients of form are really useful.They are dimensionless numbers that link the geometry of the ship with its hydrodynamic properties [3]. Especially today, with the transfer of goods overseas increasing exponentially, the need for systematic ship design with optimal features is apparent [1]. Contrary to the past, new means of analysis allow the naval architect to take on this challenge more methodically, and invest more in the design of the vessel to achieve the important parameters of floatation, maneuverability and trading potential. The same is true with the relationship between the equipment and systems that provide the desired strength and mobility [4]. In this difficult process of combining criteria to achieve the desired properties, Computer Aided Design is a powerful tool, that enables easy computing through decomposition, while the design process remains in the hands of the human. Design and computing now affect each other in a greater degree. Finally simulation properties and constant feedback from the software help the designer achieve two crucial parameters, safety and economy [5].

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References

[1] Karanassos,H. A., 2016, Commercial Ship Surveying: On/Off-Hire Condition Surveys and Bunker Surveys, Butterworth-Heinemann, Amsterdam.

 

[2] Molland, A. M. (ed.), 2008, The Maritime Engineering Reference Book: A Guide to Ship Design, Construction and Operation, Butterworth-Heinemann, Amsterdam.

 

[3] Biran, A. and López-Pulido, R., 2013, Ship Hydrostatics and Stability, 2nd ed., Butterworth-Heinemann, Oxford.

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[3] Tupper, E. C., 2013, Introduction to Naval Architecture, 5th ed., Butterworth-Heinemann, Amsterdam.

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[4] Nowacki, H., 2010, “Five decades of Computer-Aided Ship Design,” Computer-Aided Design, 42, pp. 956-969.

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STUDENT REPLY 2

Shipping has been a part of human activity since the early years of human history, yet the evolution of technology has created a breakthrough not only in the mechanical sector of ships but in the designing part as well (1,2). The increasing amount of material goods transferred by ships has created the need for novel ship designs (2). Alongside with computer aided ship design (CASD) ship designer is now capable to interfere more with the ship design rather than improving an already existing design to fit the requirements of each case always within the rules applied(4,5). Although, safety and profit remain the top priorities of every ship design (1). CASD has offered employees of the shipping industry the ability of studying and testing random scenarios that could occur during a journey such as accidents concerning either the ship or the cargo itself, thus improving the safety of the ship (1). Computer aided ship design might has upgraded tremendously  these last few years but is not yet capable of eliminating the need of a human touch (1).

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References

[1] Nowacki, H., 2010, “Five decades of Computer-Aided Ship Design,” Computer-Aided Design, 42, pp. 956-969.

 

[2] Karanassos,H. A., 2016, Commercial Ship Surveying: On/Off-Hire Condition Surveys and Bunker Surveys, Butterworth-Heinemann, Amsterdam.

 

[3] Biran, A. and López-Pulido, R., 2013, Ship Hydrostatics and Stability, 2nd ed., Butterworth-Heinemann, Oxford.

 

[4] Tupper, E. C., 2013, Introduction to Naval Architecture, 5th ed., Butterworth-Heinemann, Amsterdam.

 

[5] Molland, A. M. (ed.), 2008, The Maritime Engineering Reference Book: A Guide to Ship Design, Construction and Operation, Butterworth-Heinemann, Amsterdam.

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