International Symposium on Marine Design

670 Pages·2006·39.757 MB·670\670

RINA

INTERNATIONAL SYMPOSIUM ON MARINE
DESIGN

12 – 13 April 2006

© 2006: The Royal Institution of Naval Architects

The Institution is not, as a body, responsible for the
opinions expressed by the individual authors or
speakers

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ISBN No: 1-905040-24-5
International Symposium on Marine Design, La Spezia, Italy
CONTENTS
The Role of Ambiguity in the Art and Science of Yacht Design
Bruce Woods, Massey University, New Zealand
The Art and Science of Ship Design
David Andrews, University College London, UK
Art and Science in Yacht Design (Where does Beauty reside?)
Bruce Woods, Massey University, New Zealand
Automotive Design Methods Applied to Marine Transport Design
John Owen, Coventry University, UK
Ivan Drummond, Savannah College of Art and Design, USA
The Use of Student Design Competitions to Support the Teaching of Marine
Design
Thomas Lamb, University of Michigan, USA
Kelly Cooper, Office of Naval Research, USA
Education and Training for Marine Designers: A Students’ Perspective.
Dima Ivanov, Massey University, New Zealand
Evaluating the Design of Passenger and Crew Accommodation on Ships
Duncan Joiner, Massey University, New Zealand
Evaluation of Design Options Related to Evacuation for Enhanced Safety of
Passenger Ships
Erik Vanem and Rolf Skjong, Det Norske Veritas, Norway
Ship HVAC - Is Combined Heat and Power (CHP) Practical?
James Giles, Giles Consulting, UK
Large Luxury Yacht Design and Construction
Barry Gilmour, Oceanic Investment Corporation, UK
Multiobjective Design Optimization of a Cruise Ship
Emilio F Campana, Daniele Peri and Antonio Pinto, INSEAN, Italy
Superyacht and Passenger Ships: Practical Application of Finite Element
Methods
Angelo Tonelli and Giovanni Vacca, Registro Italiano Navale (RINA SpA), Italy
Fabio Emolumento, University of Trieste, Italy
Seakeeping: An Experimental Study of Accelerations and Motions of A High-
Speed, Double Chine Craft
Donald L. Blount, Dean M Schleicher and Peter D Buescher, Donald L Blount and
Associates, USA
© 2006: The Royal Institution of Naval Architects
International Symposium on Marine Design, La Spezia, Italy

New BV Rules for Mega Yachts
Etienne Thiberge, Nadine Le Cam, Blanche-Marie Ferlier, Nicolas Legrégeois,
Philippe Le Foll, Flavie Gohin, Michel Martinez and Benjamin Collier, Bureau
Veritas, France
The Charter Yacht and the Role of the Classification Society
Martyn Cooper, ABS Europe, UK
Robert Curry, (Consultant to ABS), UK
Analysis of Classification Societies Procedures for Structure Scantling of GR P
Motoryachts
D. Boote and C. Ighina, Dipartimento di Ingegneria navale e Tecnologie Marine,
Genoa, Italy
S. Bruckner Azimut – Benetti S.p.a., Italy
An Overview of Subdivision and Damage Stability Requirements Applicable to Large
Motor Yachts
Alberto Dachà and Paola Gualeni University of Genoa, Italy
Authors’ Contact Details

© 2006: The Royal Institution of Naval Architects
International Symposium on Marine Design, La Spezia, Italy
THE ROLE OF AMBIGUITY IN THE ART AND SCIENCE OF YACHT DESIGN

B.Woods,. Massey University, New Zealand

“Unlike writing, drawing makes up its own syntax as it goes along. The line can’t be reasoned in the mind. It
can only be reasoned on paper”. [Ref.1]

SUMMARY

We investigate the power of ambiguity its use in conceptual design our objective to move imagination towards a deeper
awareness of convergence and commonalities, in Marine Design and Naval Architecture. [Ref 1. Arnheim, 1993] Recent
developments in CAD, CFD, and new Response Surface Optimisation software and the speculative possibilities which
flow from the automation of mathematical hull modelling are briefly touched upon.

Ambiguity may seem a strange subject to discuss in the context of yacht design, which is regarded by many people as a
precise mathematical and “scientific” process. The naval architect’s approach is claimed to be essentially quantitative,
rational, analytical and numerical; the marine designer’s essentially qualitative, irrational, intuitive, and visual.

We discuss ambiguity in the context of the marine designer’s initial sketches, and the coefficients and ratio’s used for
the initial estimates and designs of the naval architect.

We argue that ambiguity is an attribute that is an essential instrument in the development of creative ideas, as that which
ambiguity leaves undefined acts as a powerful stimulant to the imagination.

We argue there is a common link between the coefficients and ratios used in technological design (Naval Architecture)
and conceptual sketches used in the artistic design (Marine Design) of vessels. Both sets of attributes can act as (avatars)
pre cursors to design in the quest for shape and form [Deforge, 1990] each do so in entirely different ways with different
categories and placements [Buchanan 1992] bound together by ambiguity.

We investigate what these attributes have in common and where their power lies [Gelertner 1998]

NOMENCLATURE There is a progression in the ideas illustrated, from the
historical forms being investigated, towards a more
“Engineering, Science and Technology” are often contemporary set of forms. The objective was to design a
interchanged and used in the same context in order to mega-yacht with Arabic influences encouraging the
simplify an argument, although strictly speaking they are client towards a design expressive of his own culture and
not precisely the same thing. history, rather than developing a conventional European
style Mega-Yacht. What cannot be seen is the substantial
1. AN EXAMPLE OF AMBIGUITY IN research undertaken before embarking on sketching, and
CONCEPTUAL DRAWINGS previous experience in another design field, which
showed that the separation between private and public
To illustrate the visual context of our discussions we spaces was an essential consideration for an Islamic
begin with examples of conceptual sketches, below is a client. This was achieved by using a raised poop deck to
composite drawing of various types of traditional provide private spaces aft and in the hull forr’d, with
Dhow’s from which partially developed ideas begin to be “public” spaces in a large wheelhouse like structure. The
formed (these sketches are a small selection from the design is also heavily symbolic (of wealth and power)
substantial number produced) The actual Dhow that served as a primary source is one
investigated but not illustrated on the sheet, a “Baghla”
“What kind of reasoning does sketching represent?” the (Characterised by 5 ports across the transom) There is a
question arises because the sketching does not consist substantial difference between the first sketch lower right,
simply of representing images held in the designers second - upper right, and third sketch - upper left, the
mind; it consists rather of a dialectic process, “the latter used to develop the next stage)
oscillation of arguments which brings about gradual
transformation of images ending when the designer
judges that sufficient coherence has been achieved”.
[Ref 1. page 70] [From: Goldschmidt Gabriela, 1991,
“The Dialectics of Sketching” Creativity Research
Journal 4:123-43]

© 2006: The Royal Institution of Naval Architects
International Symposium on Marine Design, La Spezia, Italy
[Ref. © Author. Conceptual sketches for a proposed Arabic mega-yacht]

These ideas were then moved onwards using, relatively full rendering, allowing further exploration with
loose but controlled sketches, which were still far from approximately scaled sketches of the rig, hull-form,
being resolved or cohesive enough to progress towards a exterior form and interior configuration:

[First sketch Ref © Author]
© 2006: The Royal Institution of Naval Architects
International Symposium on Marine Design, La Spezia, Italy

[Second sketch. Ref. © Author]

[Developmental sketch roughly scaled not yet fully rendered. Ref. © Author]

Goldschmidt describes the process of creative design as: British performance vehicles with a focus on historical
Jaguar designs so movement was as described, based on
“An interaction of arguments and moves. Arguments are concrete images, yet the sketches display substantial
the labours of the designer’s mind, the explorations of abstraction or ambiguity:
the task and the reasoning about it. Moves are the
physical motions engendered by the argument. Moves “Creative designing always involves the solution of a
are what psychologist’s call the behavioural aspects of problem, the carrying out of a task, and, therefore, the
human activity. The (Designers) operative moves image unfolding in the mind always refers to a goal
produce the drawings and they supply essential new food image. The final objective manifests itself at some degree
for arguments”. [Ref 1. page 70.paraphrased in part] of abstraction.”

Below we illustrate our interpretation of the “moves” “But because all abstract thinking relies on some
Goldschmidt refers to, these are creative cognitive moves, perceptual referent, even the most abstract theme is tied
in this case the student was developing concepts for a from the beginning to concrete images. These images
new Jaguar sports car – this phase of the programme was supply the designer with the primary nucleus from which
undertaken after substantial research into the form of the actual structure develops”. [Ref 1. page 71]
© 2006: The Royal Institution of Naval Architects
International Symposium on Marine Design, La Spezia, Italy
[Ref. © Jae Hoon Lee major project 2005, Massey University. The student’s objective was to develop a high
performance hydrogen powered “hatchback” sports car, specifically aimed at the young executive female market]

Following on from these the designer “moves” towards
the realisation and concrete representation of what began
as a shadowy and undefined image. The images below
show more developed ideas, but they still demonstrate
substantial ambiguity.

[Ref. © Jae Hoon Lee major project 2005, Massey University]

[Ref. © Jae Hoon Lee major project 2005, Massey University] Note the Jaguar “Face”!]

[Ref. © Jae Hoon Lee major project 2005, Massey University]

© 2006: The Royal Institution of Naval Architects
International Symposium on Marine Design, La Spezia, Italy
The goal image and Virtual image and final 3D scale different process from the numerical approach, has its
model and of the design are shown below, a photo- own validity, it is not a random and directionless process,
realistic virtual model, detailed physical model definitely science on the other hand:-
induce a sense of resolution, or finality, that discourages
change, that is their purpose. (That is not to say that “Science and engineering on the other hand has: Canons
physical conceptual models cannot be used in design of rationality and objectivity agreed by consensus in the
development, this is common practice. Effective but scientific community for assessing scientific theories.
expensive and only possible where substantial skilled Among them are predictive powers, degree of unification
human, and financial resources are available) of disciplines, rigor of foundations, and agreement with
conservation laws. Yet just as in any creative enterprise,
the rules of procedure are not always strictly adhered to
and are sometimes set aside”. [Ref .5 page 389]

There have been many methodologies proposed for
industrial design and architecture, these often have
substantial validity yet most designers we know, do not
follow a specific methodology although most use a
similar elements in their approach.

For example we have often experienced the apprehension
of what one senses will be a total and appropriate
response to a design without being able to define
precisely, in any visual way, what this may be. We
[Ref. © Jae Hoon Lee major project 2005, Massey believe this precursor to design or “avatar” is a common
University] Final Renderings e x p e r i e n c e , o n e w e o f t e n define as an intuition for lack of
a more precise definition. (This apprehension may be
partial or substantial or complete yet undefined)

The problem is that while this may be valid it is essential
to avoid preconceptions; these freeze the design making
conceptual movement impossible, thereby limiting the
creative possibilities. This takes substantial experience
and judgement.

[Ref. © Jae Hoon Lee major project 2005, Massey When the designer enters into a dialogue with himself
University] Final Virtual model about the design, the development process using sketches,
is essentially an iterative process, the movement within
the design space is not unidirectional as the designer
explores and moves closer to an appropriate “fit”. In the
case of marine design there is, and must be, a constant
reference back to the physical performance requirements
of the design, be they structural, constructional, or
emotional, psychological, symbolic, ergonomic etc.

This referential iterative process is familiar and common
in all design activity we believe.

3. YACHT DESIGN METHODOLOGY

There are also various methodologies used by yacht
designers. Again these are all similar. The usual analogy
used to describe the methodology is the design spiral,
this is a iterative “trial and error”, procedure where
[Ref. © Jae Hoon Lee major project 2005, Massey staring with a set of assumptions the designer works
University] 3D Scale model through roughly eleven stages spiralling in towards as
close a “fit” as possible to satisfy the design requirements,
2. MARINE DESIGN METHODOLOGY this is repeated through many iterations until the desired
result is produced.
The Marine Designer in dealing with qualitative form,
employs an analytical methodology which, although very
© 2006: The Royal Institution of Naval Architects
International Symposium on Marine Design, La Spezia, Italy
At the initial stage the designer will define a set of sailing conditions, with 3D virtual models and
geometric dimensions and select coefficients and ratios. performance data projected onto the monitor in real time.
In yacht design these relate to linear dimensions,
volumes, mass, hydrostatic and hydrodynamic properties, The implications of the automation of engineering and
sail area to displacement ratio. etc. Probably the most naval architectural techniques such as this are interesting
elementary are overall dimensions and some reasonable in relation to marine design, as it indicates (to the author
estimate of weight (displacement) at least) that in the future the naval architect will be freed
to undertake more creative development in technical
These various figures are then applied to the design (for example new types of hullforms) while the
development of an initial set of lines. less demanding minimum condition designs will allow
substantially more creative input and design control by
Most yacht designers will build an elementary the marine designer.
mathematical model initially, then begin to develop a
lines plan from the mid-ship section, waterplane, profile, Below are a couple of very rough concept sketches for an
plan etc. [for an excellent guide Ref.7 is recommended] 18ft trailer sailer, these were used in teaching to provide
examples of just how widely variations for a set of
Nowadays they will probably begin with an existing design parameters might be interpreted, we hope they
design on file in their computer, or set up a basic grid and serve to illustrate that, at the initial conceptual stage at
sketch in the various views and sections needed to work least, how qualitative judgements are an essential part of
through developing a set of lines. the process.

Examples relating to Geometric shape and proportion, Larssen and Eliasson [Ref.7] produce what is now
(Linear dimensions and Areas) undoubtedly the most popular (and useful) general text
• LOA (Length overall of hull) on yacht design, interestingly they have this to say about
• DWL (Design waterline) the nature of yacht design:
• BOA (Beam overall)
• BWL (Beam waterline) “Yacht design is by its very nature a quantitative process.
• BWLmax (Maximum beam on waterline) A designer, professional or amateur, is not much helped
• B/L ratio (beam to length) etc. by qualitative reasoning. It is not enough to know that
• S/A Sail Area the hull can withstand a greater load if the skin is made
• Midship Area coefficient thicker, or that stability is increased by more lead in the
• Waterplane Area coefficient keel. What he needs to know is the minimum skin
thickness and the least amount of lead need in the keel
Examples relating to Topological shape (or Volumes) for the yacht to be safe under all possible conditions. If
• Froude number he is not able to compute these quantities the yacht may
• S/L (speed to length) be slower and more expensive than necessary, and worst
• Prismatic coefficient of all, it may be unsafe”. [Ref .7 page 3]
• Block coefficient
• Displacement/Length ratio Contradictory though it may seem, we agree with this
• Length/Displacement ratio (Circular M) statement, a substantial part of the nature of yacht design
• Sail Area/Displacement ratio etc. is quantitative, however we believe that the designer is
continually making qualitative evaluations and
Even at a very early stage if minimum performance judgements of their proposals as a design develops.
requirements such as sailing performance are critical then Especially in the initial conceptual stages, where the
the design will be put through some form of sailing overall configuration and layout is conceived. As the
performance analysis or comparative analysis. (VPP, programme moves forward the design requires
Velocity Prediction Programme, or CFD, computer fluid progressively more focus on precise engineering analysis,
dynamic analysis etc) to refine and optimise the technical design of hull and all
aspects and the hydrodynamics of the keel and rudder,
If minimum condition is the primary driving force such rig or the structural design of the vessel.
as an America’s Cup yacht, then increasingly we see use
being made of hullform optimisation programmes and In minimum condition design there must be a very
substantial tank testing. Hardly surprising as the costs of precisely defined set of figures against which the actual
not achieving the required performances are substantial! performance of any design can be measured, (As in the
case of an America’s cup boat, where millions may be
We anticipate that the automation of design in this way spent achieving what in normal terms would be
will continue to increase; one envisages quite soon miniscule gains)
various virtual design options being sailed off against
one another, around a course using a specific set of
© 2006: The Royal Institution of Naval Architects
International Symposium on Marine Design, La Spezia, Italy
However we must also remember that any minimum The Traditional option
condition is a chosen condition, and “optimum
performance” at least in pleasure and leisure craft, must
include the human psychological, emotional, symbolic,
and physical performance requirements, in an effective
design. For example some clients are very demanding
regarding the symbolic aspects of a design, as expressed
by the visual style of the vessel, responses in this case are
not physical they are emotional, so one can argue they
are subjective and cannot be evaluated. We don’t believe
that is entirely the case but will leave that argument for
now.

Let us now look at ambiguity in a coefficient, as an
example the Prismatic Coefficient. This compares the
volume of a prism projected fore and aft the length of
LWL, from the midship (or largest) section against the
volume of a rectangular prism corresponding to LWL &
BWL & Canoe body draft.
Cp = ∇
AM×L

Where AM = the area of the midship or largest section Modern Design:
of the immersed hull. 1. D/L = 150
Where L = the Design Waterline. 2. Cp = 0.58
Where = ∇ Volume of Displacement ∆
3. = approximately 1770lbs (approx 800kg)

4. LOA = 18ft 0” (5.5m)
The Cp relates to the distribution of the immersed volume
5. DWL = 14ft 9” (4.5m)
of the vessel. But it says nothing at all about the shape of
6. BOA = 7ft 10” = 7.8ft (2.4m)
this, which may vary substantially from design to design.
7. BWLmax @ DWL = 6.0ft (1.9m)
The designer will manipulate this shape in developing a

design and may work through a substantial number of
The Modern option
iterations before being satisfied (the exploration in a high

performance craft would involve numerical analysis and

comparative analysis offered by V.P.P. etc)

3.1 A SIMPLE EXAMPLE 18FT
CENTREBOARD DESIGN

Below are two rough sketches of a simple conceptual
design, both examples with the same coefficients (only
Cp and D/L are shown) and nearly identical geometric
dimensions, any variations are deliberate.

Traditional Design:
1. D/L = 150
2. Cp = 0.58
3. ∆ = 1770lbs (approx 800kg)
4. LOA = 18ft 0” (5.5m)
5. DWL = 17ft 5” (5.3m)
6. BOA = 7ft 10” = 7.8ft (2.4m)
7. BWLmax @ DWL = 6.0ft (2.24m)
8. Stem height 1.0m
Lowest point on sheer 0.82
Transom height 0.85

© 2006: The Royal Institution of Naval Architects