The impact of technology and computers

Over the last half-century technology has had a tremendous impact upon how ships are designed, built, operated and maintained. One could mention a myriad of examples but the following will serve as illustrations:

(1) Satellites in space have made it possible for ships to locate their position to within a few tens of metres using global positioning systems. The satellites can also pick up distress signals and locate the casualty for rescue organizations. They can measure sea conditions over wide areas and facilitate the routeing of ships to avoid the worst storms.

(2) Materials technology. Modern materials require much less maintenance, reducing operating costs and manpower demands. Reinforced plastics can be used for local structures, superstructures and for the main hull. Such plastics can be configured to enable them to meet the local stresses efficiently. For example, carbon fibres can be aligned with the main stress direction. New hull treatments permit much longer intervals between dockings leading to higher ship usage rates and reduced costs of ownership. They also contribute to the battle against pollution of the sea environment.

(3) Modern equipments are generally much more reliable with increased mean times between failures. Modularization and repair by replacement policies reduce downtime and the number of repair staff needed on board.

(4) Electronically controlled operating and surveillance systems enable fewer operators to cope with large main propulsion systems and a wide range of ship's services.

The biggest impact has been the influence of the computer. Indeed, computers have made a vital contribution to many of the changes referred to above. But it is in the sequence of design, build, maintaining and running of ships that their influence has been greatest for the naval architect. In some cases these processes have changed almost beyond recognition although the underlying principles and objectives remain the same. As examples:

In design

(1) CAD systems enable preliminary designs (PD), in response to a client's wishes, to be produced more rapidly, in greater detail and with greater accuracy than ever before. Large databases of type ships can be called upon. If the design is novel specialist software is usually available to assess all the major characteristics.

(2) Once the customer has agreed the PD the computer already holds the basic definition with which to start the contract design phase. The hull form, machinery requirements, layouts and systems can be produced with all the data accurately integrated and recorded. Any changes in form can be reflected in compartment shapes, and the volumes recalculated, and so on. Changes in structure are reflected in weight, hydrostatic and stability up-dates. Computer-based directories of materials and equipment help in selecting equipments and fittings and integrating them into systems of known performance, cost and reliability.

(3) Computer controlled draughting machines and virtual reality techniques can be used to inform the client about the design and provide a means for the customer, or classification society to make an input to the design development. Virtual reality can be used to show what the ship will look like from all angles, both internally and externally. These can be used instead of mock-ups or models to assist in achieving efficient layouts. A person can be taken for what is termed a 'walk through' of ship before the design leaves the drawing board.

(4) The strength of CAD systems is that they are integrated suites of related programs. These can accommodate advanced programs for such things as structural strength evaluations, motion predictions and so on.

In production

(1) Once the design is approved to build the data can be passed to the chosen shipyard in digital form. This reduces the risk of

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misinterpretation of drawings and other data. Provided the designer's CAD and builder's computer-aided manufacture (CAM) systems are compatible it also reduces the builder's task in producing information for the production process.

(2) The database is available to the builder to order material, equipment and fittings for the build process. The builder will develop the database as the design is developed to provide all the details for manufacture and, later, for passing on to those who have to maintain the equipments and systems.

(3) In production the computer can deal with routine matters like stock control. It can control cutting and welding machines ensuring greater accuracy of fit, facilitating more extensive pre-fabrication and reducing built in stresses. It should lead to a better, more consistent, quality of product. Where more than one ship of a class is being built the ships will more closely resemble each other. This makes future modification easier to control.

In operation and maintenance

(1) In the same way as the systems facilitated the passing of information from designer to builder, they make it easier to pass information on to those who are to operate and maintain the ship. Hydrostatic, hold and tank capacity, stability and strength data can be fed into the ship's own software systems to assist the captain in loading and operating the ship safely.

(2) Listings of equipment and fittings, with code numbers, will ensure that any replacements and spares will meet the form, fit and function requirements. One advantage of the computer is the potential to reduce the amount of paper. Where hard copy is required some form of microfiche can be used, again reducing the stowage volume and weight.

(3) Data can be provided on the layout of systems and how the designer intended they should be operated. Computer controlled displays, fed with information from a whole range of remote sensors, assist those who are responsible for decisions. Sensors can give early warning of incipient failures.

(4) Computer-based decision aiding systems can be installed. For example, the master can be prompted on the loading sequences to eliminate the possibility ofjeopardizing the stability or strength. In warships they can assist the captain when under enemy attack by suggesting the optimum actions to take in defending the ship. It needs to be emphasized that they are only used in an advisory capacity in these roles. They do not reduce the master's or captain's responsibility.

(5) Computer-based simulators can assist in training navigators, machinery controllers and so on. These simulators can be produced to various levels of realism, depending upon the need. They may merely reproduce the display consoles and control levers, leaving the computer to calculate how the ship, or system, will respond to the input made. They can be mounted on a moving platform to reproduce the ship movements in response to control movements. Motions can be imposed representing the ship's response to waves to study the ability of an operator to remain vigilant under motion conditions. The computer can provide external stimuli, through goggles or screens, which the operator can expect in practice. For instance, a navigational simulator can provide pictures of a harbour and its approaches. Other ships can be added for extra realism.

(6) All the on board tasks of management can benefit from the appropriate software.

(7) The database provides a useful input to any surveyor. It shows what should be fitted and provides the 'hooks' upon which the results of successive surveys can hung. In this way the gradual deterioration of structure, say, can be logged, showing up potential trouble spots and helping decide when remedial action is needed.

The above brief description shows how all-pervading the computer has become. It must be remembered though that it is only a tool, albeit a very powerful one. As such it must, like all tools, be used intelligently by those who understand how to get the best out of it. It is an aid to the human, although artificial intelligence techniques can be used to provide great assistance to a relatively inexperienced person. So-called expert systems can store information on how a number of very experienced engineers would view a certain problem in a variety of circumstances. Thus a less experienced person (at least in that particular type of vessel or situation) can be guided into what might be termed good practice.

This is not to say that the tasks of the designer, builder or operator have been made easy. Some of the more humdrum activities have been removed such as tedious manual calculations of volumes and weights. But more knowledge is needed to carry out the total task. Whereas in the past a simple longitudinal strength calculation, using a standard wave, was all that was possible, a much more complex assessment is now usually demanded. That is if its cost can be justified. What waves should be taken as the design conditions for operation and for survival? How should the mesh be arranged in a finite element analysis? So the decisions pile up and the answers are not all easy ones. If they were the

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naval architect would not be needed and the master could be replaced by the computer.

How To Have A Perfect Boating Experience

How To Have A Perfect Boating Experience

Lets start by identifying what exactly certain boats are. Sometimes the terminology can get lost on beginners, so well look at some of the most common boats and what theyre called. These boats are exactly what the name implies. They are meant to be used for fishing. Most fishing boats are powered by outboard motors, and many also have a trolling motor mounted on the bow. Bass boats can be made of aluminium or fibreglass.

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