Trans RINA, Vol 153, Part A1, Intl J Maritime Eng, Jan-Mar 2011
hence, clearer imperative. This range of acquisition complexity is mirrored in the range of ship design sophistication highlighted by the author at Table 4 in the IMDC 2006 State of Art Report [16] and reproduced below as Table 1. It shows a spectrum of approaches to ship design, distinguishing them by the relative novelty in the types of design and hence the design resources demanded for them to be undertaken. Beyond this it is also worth stating that the nature of preliminary ship design has been spelt out by various practitioners and many of these expositions have recently been reviewed by the author, as part of a paper with a co-worker, in a detailed presentation of preliminary ship design [17].
Finally in emphasising the importance of preliminary ship design, it is considered useful to reiterate that it is the only time designers can be truly divergent and radical in their thinking. If new and different options are not considered then, they never
doesn’t push the requirements owner
requirement, again the chance will not come downstream once the design team is on the roller coaster of project management. The design
downstream process with confidence in their choice of option to be developed. This comprehensive
3.1 CONCEPT EXPLORATION
This initial design stage can be said to comprise a wide- ranging exploration, which starts at the initiation of investigations for a new ship design. It should be an extensive consideration of all possible options and, typically, include modernising existing ships, modifying existing designs and exploring the full range of, for example:
(i) packaging of the primary function (e.g. aircraft, weapons
or sensors
cargo/passengers for naval auxiliaries or, even, merchant ships);
(ii) capability of the ship to deliver the functions (e.g. speed, endurance, standards);
(iii) technology options to achieve the functions and capability (e.g. existing technologies,
will be; if the designer to stretch the
team should enter that is best achieved by a
and wide design exploration in the
concept phase. Without this the team remains vulnerable to the many likely attempts to deflect and challenge their chosen design and its development. All this argues for increased investment by the wider design community in the front end of the ship design process, which is essentially the Requirements Elucidation task.
Table 1: Types of Ship Design with Examples from Naval Ship Design [16]
Type second batch Example Batch 2 Type 22 frigate
simple type ship many naval auxiliary vessels evolutionary design simple synthesis
a family of designs UCL student designs
architectural synthesis UCL design studies radical configuration SWATH, Trimaran radical technology US Navy Surface Effect Ship
Before considering the manner in which the initial phase of ship design ought to be carried out, it is considered sensible to spell out, in a little more detail, the overall concept process for a major new naval ship design. This can be done in terms of three initial overlapping design stages, comprehensively presented in the author’s 1994 paper on the preliminary design of warships [18]. Outlining each stage in a little more detail:-
materials and systems, enhanced technological/ configurational options, reduced technology levels).
These explorations may well be cursory or may show the need to further pursue more than one distinct option and may
require 3.2 research programmes, to de-risk CONCEPT STUDIES
Assuming only one or two options are to be taken forward, the wide ranging but cursory nature of the initial exploratory stage is unlikely to have investigated in any depth the perceived design drivers and the impact of various choices on function, capability and technology. This next stage is dependent on the type of vessel (i.e. combatant, aircraft carrier) and degree of novelty (e.g. conventional monohull, unconventional configuration), as well as a range of issues to be addressed from payload demands through speed and endurance to style issues, such as those associated with design life, signatures, survivability and complement standards. All these issues normally merit investigation before the design is too fixed. They can also significantly
influence the
downstream design but, more importantly, they need to be debated with the requirements owner, since their impact on the ship’s performance and affordability should be part of the requirements elucidation dialogue, before the form and style of the solution are too precisely fixed.
3.3 CONCEPT DESIGN
This final stage prior to approval to commit to a more substantial design effort (i.e. in UK MoD terms, prior to Initial Gate decision) is primarily focused on the design (and costing)
information necessary
approval to proceed is based on sufficient information and that the process, beyond that approval, proceeds coherently. Typically, the stage is dominated by cost capability trade-off studies and the interaction with any
technologies, or revisiting (not for the last time) the initial operational concept.
key enhanced for a combatant;
to ensure the
©2011: The Royal Institution of Naval Architects
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