Submarine for Malaysia

The first submarine for Malaysia had finally arrived. Normally we read about political and similar comments on the submarine. We seldom hear about the technical aspects of submarine. Perhaps Malaysians are not interested in submarine as a defence tool but to delve further on its procurement aspects, etc.

Most of our ASEAN members had their own submarines. Our second submarine, also from DCN France of Scorpene design will arrive sometime next year, perhaps.

The design process—This process is composed of three design phases: (1) basic design, (2) contract design, and (3) detail design. The levels of labor, preparation time, and costs associated with each phase increase exponentially as the process progresses. Design creativity and flexibility are essentially limited to the basic design phase—the mission system, including its submersible system, being well defined at the beginning of contract design.

The design process, at this point, is discussed from the perspective of the mission system (the design of its submersible system. As has been seen, this system is composed of (I) systems which may be labelled as new construction or existing systems. Design efforts focus on the total, or "from-scratch," design of new construction systems and on the selection of suitable existing systems and their alteration, if required, to convert them to (I) systems. The submersible, herein, is considered to be a new-construction (I) system.

Basic design is the primary design phase concerned with how best to accomplish what the potential user/owner of the mission system wants to do underwater as set forth by his mission requirements. In general, this phase involves:

1. Development of performance requirements, or (I) system capabilities, from the mission requirements.

2. Determination of the principal characteristics of the (I) systems required to achieve these capabilities, which enable new construction systems to be designed and existing systems to be selected and altered if necessary.

3. Estimation of capital and operating costs of (I) systems.

4. Identification of one or a few mission systems from among a series of alternatives which optimally meet performance requirements to the extent possible considering design constraints acting.

5. Refining and firming-up characteristics and cost estimates of the (I) systems composing the optimum conceptual design(s).

The conceptual design stage of basic design is concerned with the first four of these functions—function four, herein, is based on cost-effectiveness as the optimization criterion. The preliminary design stage of this phase is concerned with the fifth function.

Each (I) system, in turn, has unique capabilities, characteristics required to achieve these capabilities, and costs associated with providing these characteristics. Certain unique (I) systems may appear in more than one combination but individual combinations are not duplicated in other alternatives. Mission system alternatives may be generated by (1) varying performance requirements with the cascading effect of varying (I) systems' capabilities, characteristics and costs and (2) varying (I) systems' capabilities, characteristics, and costs in ways each of which meet a specific set of performance requirements. Alternatives generated in this manner contain information necessary to conduct the search for the optimum, cost-effective mission system(s).

Combinations of (I) systems forming mission system alternatives may vary in number, type/capabilities, and status. These features are related to functions required to accomplish mission tasks, the time frame for completing these tasks, if critical, and economic considerations. A mission profile, derived from mission requirements, is useful in providing functions and time-frame information—its usefulness increasing as the complexity of the mission increases. This profile is a chronological listing of all events occurring from the mission's beginning to end and including time-frame data where necessary. For example, the profile of a certain demanding mission, requiring short response times, identified the number, type, and certain capabilities of (I) systems needed to serve the submersible transportation function. In this instance, four types of (I) systems, a special flatbed trailer, an aircraft, a surface ship, and a submarine, were necessary to provide land, air, sea-surface, and sub-sea transportation.

In the first instance, it will be recalled that all of these alternatives must meet performance requirements and be technically feasible from the producibility/availability and operability points of view. Thus, in forming these alternatives, it may be found that certain performance requirements cannot be met for technical feasibility reasons—that they must be altered to make the alternatives in question viable. In the second instance, cycling the alternatives through the optimization process in searching for the optimum mission system(s) may reveal that changes in some performance requirements will result in a better solution to the design problem from the cost-effectiveness view. In either case, these changes may also necessitate changes in the mission requirements so that they can be met by the altered set of performance requirements.

The conceptual design(s) of the selected mission system(s) can now be completed by developing the primary characteristics of the (I) systems not considered in the feasibility studies. The identification of more than one optimum conceptual design means that the "optimization curve" is reasonably flat over a limited range of alternatives—that there is little to choose between them. In this instance, the user/owner may select one of them based on subtleties not heretofore considered, or more than one may be carried forward into preliminary design. The mission system(s) carried forward should have associated performance requirements firmed up and provide baseline (I) system characteristics which are further developed and refined during the preliminary design stage.

Preliminary design, as noted, is the second stage of basic design and is concerned with this phase's fifth function. Starting with baseline data provided by the selected conceptual design(s), it refines and firms up the major characteristics of (I) systems, the MIDCs they exert on each other, and cost estimates associated with them. In summary, it provides a precise engineering definition of the mission system and assurance that the design goal can be attained.

These discoveries should be few in number and minor in their effect on the requirements. A major discovery of this nature would, most likely, raise doubts about the validity of the selected conceptual design(s) and be cause for repeating the conceptual design stage or terminating the design altogether.

Contract design requires yet further refinement of design and additional detail. It yields contract plans and specifications necessary for interested parties to bid on the construction of new (I) systems or the alteration of existing (I) systems. It also provides contractual documents for the construction and alteration work.

Specifications delineate quality standards of material and workmanship as well as setting forth performance expectations for the (I) systems and their subsystems. They also describe tests and trials which must be performed successfully before acceptance of the systems.

Detail design is the final phase of the design process and entails the development of detailed working plans from which the (I) systems are constructed or altered. In one sense, it is really not a design phase since all the creative design effort is done in the preceding phases, the design being unequivocally defined prior to entering this phase. It does, however, require the greatest amount of work of all the phases and is often undertaken by entities building or altering the system.

The post-design process—This process is composed of three activities: construction/alteration, test and evaluation, and operation. Although this publication is not directly concerned with these activities, there are two reasons for including them in this overall perspective: (1) They constitute important sources of input to new designs and feedback to the design in question, and (2) they are subject to certain existing MEDCs and will influence the future impact of MEDCs on following designs.

Regarding (1), post-design experiences may reveal that items composing the (I) systems fail to meet or exceed design expectations. Failure in this regard results in the redesign of the offending item or, at least, a lowering of confidence in it which may lead to restrictions being placed on performance. For example, the maximum operating depth of a submersible may be made shallower than stated in the performance requirements due to the discovery of metallurgical deficiencies in the pressure hull's material. Meeting or exceeding expectations, of course, raises confidence in the item which effectively documents the soundness of the current design in this regard and encourages its use in future designs.

Regarding (2), the principal MEDCs of interest here are in the legal/quasi-legal category—rules and regulations of classification societies and various federal agencies including certifying authorities. These MEDCs impact on all aspects of the design and post-design processes. Post-design activities furnish feedback to these MEDCs, causing them to be maintained or altered as experience warrants. In this sense, then, the post-designs process is also a source of input to future designs through its influence on future MEDCs.