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INTRODUCTION TO NAVAL ARCHITECTURE AND OCEAN ENGINEERING

INTRODUCTION TO NAVAL ARCHITECTURE AND …160.75.46.2/staff/ebru/Int.NavalArch/HANDOUT1.pdf · With this essential background established, a student can begin to apply his or her

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INTRODUCTION TO NAVAL ARCHITECTURE

AND OCEAN ENGINEERING

What is engineering?

Engineering is an open-ended process during which

scientific knowledge is converted to useful products for

the benefit of society

Engineers are problem-solvers; they must assimilate

numerous skills (e.g. math & physics) and resources

(e.g. oceanic data) in order to solve a problem through

means such as the design of a structure, vehicle or

system

In order to perform this, an engineer must be

inquisitive and broadly educated, he or she must be

knowledgeable in the sciences and in the language of

engineering - namely mathematics, and he or she must

be well educated in the fundamental courses common

to all engineering disciplines - courses in: statics,

dynamics, thermodynamics, fluid dynamics, materials,

electrical theory, experimental techniques etc.

With this essential background established, a student

can begin to apply his or her knowledge to a specific

engineering problem - such as the design of a ship or

an offshore structure.

Naval architecture is that field of engineering which

addresses how we can apply our acquired wealth of

knowledge to design, test, build, and operate ships.

All types of ships and boats - recreational to naval,

small to big, operating on or under the sea, sails to

nuclear, etc.

Some of the features of a ship

• A ship is a self-contained entity - it must operate for

extended periods in a very hostile environment

(storm tossed seas, submerged, corrosion).

• A ship has a crew, it is self-propelled, and carries

those systems {electrical generation and distribution,

water and sewage, HVAC, habitability (staterooms,

galley, etc.), cargo handling, weapons, propulsion,

maneuvering, and many others} which are essential to

economically and effectively accomplish its mission or

missions.

• A ship can have a very long service life.

• A ship has to be able to protect itself (navigational aids,

mobility, maneuverability, weapons systems) and, if

necessary, to absorb punishment (watertight subdivision,

double hulls, pumps, and fire fighting).

• A ship is very complex . To design a ship is an extremely

challenging but immensely interesting task. An

undergraduate education in naval architecture will

provide you the tools to begin to pursue this engineering

challenge.

• You will be an engineer, a naval architect, and an

individual who is capable of finding viable economical

and technical solutions to a variety of complex and

open-ended engineering problems. Such as:

• How to safely and efficiently move a variety of cargoes

across the world’s oceans (cruise liners, tankers,

containerships, heavy lift ships, tug-barge units, etc.).

• How to effectively project your nation’s economic,

political, and military objectives across the seas (aircraft

carriers, frigates, submarines, cargo ships, etc.).

• How to best protect your nation’s coastline, resources,

and waterborne trade (patrol craft, buoy tenders, oil

spill response ships, escort tugs, etc.).

• How to safely explore and wisely exploit the abundant

resources found in the ocean’s depths and in its ice

covered areas (drill ships, fishing boats, oceanographic

ships, icebreakers, etc.).

• How to provide better boats and ships for

entertainment, sport, and recreational boating

(excursion boats, casino boats, sailing yachts, motor

yachts, etc.).

SHIPS

Ships are a vital element in the modern world. They still

carry some 95 per cent of trade. In 1994 there were more

than 80 000 ships each with a gross tonnage of 100 or more,

representing a gross tonnage of over 450 million in total.

Although aircraft have displaced the transatlantic liners,

ships still carry large numbers of people on pleasure cruises

and on the multiplicity of ferries operating in all areas of the

globe. Ships, and other marine structures, are needed to

exploit the riches of the Deep.

Although one of the oldest forms of transport, ships, their

equipment and their function, are subject to constant

evolution. Changes are driven by changing patterns of world

trade, by social pressures, by technological improvements in

materials, construction techniques and control systems, and

by pressure of economics. As an example, technology now

provides the ability to build much larger, faster, ships and

these are adopted to gain the economic advantages those

features can confer.

NAVAL ARCHITECTURE Naval architecture is a fascinating and demanding discipline.

It is fascinating because of the variety of floating structures

and the many compromises necessary to achieve the most

effective product. It is demanding because a ship is a very

large capital investment and because of the need to protect

the people on board and the marine environment.

One has only to visit a busy port to appreciate the variety of

forms a ship may take. This variation is due to the different

demands placed on them and the conditions under which they

operate. Thus there are fishing vessels ranging from the small

local boat operating by day, to the ocean going ships with

facilities to deep freeze their catches. There are vessels to

harvest the other riches of the deep - for exploitation of

energy sources, gas and oil, and extraction of minerals. There

are oil tankers, ranging from small coastal vessels to giant

supertankers.

Other huge ships carry bulk cargoes such as grain, coal or

ore. There are ferries for carrying passengers between

ports which may be only a few kilometres or a hundred

apart. There are the tugs for shepherding ships in port or

for trans-ocean towing. Then there are the dredgers,

lighters and pilot boats without which the port could not

function. In a naval port, there will be warships from

huge aircraft carriers through cruisers and destroyers to

frigates, patrol boats, mine countermeasure vessels and

submarines.

Besides the variety of function there is variety in hull form. The

vast majority of ships are single hull and rely upon their

displacement to support their weight. In some applications

multiple hulls are preferred because they provide large deck

areas without excessive length. In other cases higher speeds

may be achieved by using dynamic forces to support part of the

weight when under way. Planing craft, surface effect ships and

hydrofoil craft are examples. Air cushion craft enable shallow

water to be negotiated and provide an amphibious capability.

Some craft will be combinations of these specialist forms.

The variety is not limited to appearance and function.

Different materials are used - steel, wood, aluminium and

reinforced plastics of various types. The propulsion system

used to drive the craft through the water may be the wind,

but for most large craft is some form of mechanical

propulsion. The driving power may be generated by diesels,

steam turbine, gas turbine, some form of fuel cell or a

combination of these.

The power will be transmitted to the propulsion device

through mechanical or hydraulic gearing or by using

electric generators and motors as intermediaries. The

propulsor itself will usually be some form of propeller, but

may be water or air jet. There will be many other systems

on board - means of manoeuvring the ship, electric power

generation, hydraulic power for winches and other cargo

handling systems.

A ship can be a veritable floating township with several

thousand people on board and remaining at sea for several

weeks. It needs electrics, air conditioning, sewage

treatment plant, galleys, bakeries, shops, restaurants,

cinemas, dance halls, concert halls and swimming pools.

All these, and the general layout must be arranged so that

the ship can carry out its intended tasks efficiently and

economically.

The naval architect has not only the problems of the

building but a ship must float, move, be capable of

surviving in a very rough environment and withstand a

reasonable level of accident. It is the naval architect who

'orchestrates' the design, calling upon the expertise of

many other professions in achieving the best compromise

between many, often conflicting, requirements.

The profession of naval architecture is a blend of science

and art. Science is called upon to make sure the ship goes

at the intended speed, is sufficiently stable and strong

enough to withstand the rigours of the harsh

environment in which it moves, and so on. The art is in

getting a judicious blend of the many factors involved so

as to produce a product that is not only aesthetically

pleasing but is able to carry out its function with

maximum effectiveness, efficiency and economy.

Naval architecture is a demanding profession because a

ship is a major capital investment that takes many years

to create and is expected to remain in service for perhaps

twenty-five years or more. It is usually part of a larger

transport system and must be properly integrated with

the other elements of the overall system.

The geography of, and facilities at, some ports will restrict the

size of ship that can be accommodated and perhaps require it to

carry special loading and discharging equipment. An example of

this is the container ship. Goods can be placed in containers at

the factory where they are produced. These containers are of

certain standard dimensions and are taken by road, or rail, to a

port with specialized handling equipment where they are loaded

on board.

At the port of destination they are offloaded on to land

transport. The use of containers means that ships need spend

far less time in port loading and unloading and the cargoes are

more secure. Port fees are reduced and the ship is used more

productively.

The designer must create the best possible ship to meet the

operator's needs. In doing this he must know how the ship will

be used and anticipate changes that may occur in those needs

and usage over the years. Thus the design must be flexible.

History shows that the most highly regarded ships have been

those able to adapt with time.

Most important is the safety of ship, crew and environment.

The design must be safe for normal operations and not be

unduly vulnerable to mishandling or accident. No ship can be

absolutely safe and a designer must take conscious decisions as

to the level of risk judged acceptable in the full range of

scenarios in which the ship can expect to find itself. There will

always be a possibility that the conditions catered for will be

exceeded and the risk of this and the potential consequences

must be assessed and only accepted if they are judged

unavoidable or acceptable.

.

Even where errors on the part of others have caused an

accident, the designer should have considered such a

possibility and taken steps to minimize the consequences. For

instance, in the event of collision the ship must have a good

chance of surviving or, at least, of remaining afloat long

enough for passengers to be taken off safely. This brings with it

the need for a whole range of life saving equipment. The heavy

loss of life in the sinking of the Estonia in 1994 is a sad

example of what can happen when things go wrong. Cargo

ships may carry materials which would damage the

environment. if released by accident. The consequences of

large oil spillages are reported all too often.

Other chemicals may pose an even greater threat. The

bunker fuel in ships is a hazard and, in the case of

ferries, the lorries on board may carry dangerous loads.

Clearly those who design, construct and operate ships

have a great responsibility to the community at large. If

they fail to live up to the standards expected of them

they are likely to be called to account.

Over the years the safety of life and cargo has prompted

governments to lay down certain conditions that must

be met by ships flying their flag, or using their ports.

Because shipping is world wide there are also

international rules to be obeyed. International control

is through the International Maritime Organisation.

OCEAN ENGINEERING

The key to unlocking the last frontier on earth lies in the

hands of the ocean engineer. Ocean scientists provide

us with a basic knowledge of the ocean environment, but

it is up to the ocean engineer to apply modern

engineering principles in order to work in this

environment and utilize it more effectively. By blending

the fundamentals of mathematics, physics, material

science, and oceanography with the basic elements of

civil, mechanical, and electrical engineering, the ocean

engineer is able to apply this knowledge to ocean

materials, power systems, acoustics, wave mechanics, life

support systems, and the design of a wide variety of

ocean vehicles and structures.

Ocean engineering is a relatively young, extremely

varied and remarkably exciting field of engineering.

Oceans truly are the last frontiers remaining on earth,

and it is up to us as engineers to find ways to identify,

investigate and utilize ocean and coastal resources while

at the same time protecting them from the destructive

effects of human activities.

While engineering has been around for hundreds of

years, the term "ocean engineering" has been in

existence for only about 50 years. However, there are

certainly a myriad of engineering problems related to

our oceans that have existed for quite some time --

most of which still need attention! And since more

than two-thirds of the earth is covered by water, and

more than 98% of the biological living space exists in

the oceans, wouldn't it make sense if at least two-thirds

of engineers were ocean engineers?

We all know that this is not the case, and those who

choose ocean engineering have quite a collection of

problems to solve ... Ocean engineering is a field of

engineering that has many opportunities within it to

make an impact!

What is Ocean Engineering?

Ocean engineering is one of the most varied engineering

disciplines. The ocean engineering education includes

the standard fundamental engineering courses such as

statics, dynamics, strength of materials, materials

science, thermodynamics, fluid mechanics, along with

other applied engineering courses. Since ocean

engineering encompasses so many different areas and

types of problems, there are many different types of

elective courses offered. Each of these elective courses

strives to utilize and reinforce the fundamental tools

learned, while expanding the problem-solving capability

of each student.

Ocean engineering program includes coverage of the

following disciplines within ocean engineering area

(through elective courses and subject matter with core

and design courses):

Coastal Engineering - Learn the dynamic interaction of

the ocean and its shore

An ocean engineer ...

Develops shore protection systems

Designs harbors and ports

Deals with Civil Engineering issues in the coastal

environment

Offshore Engineering - Learn to design structures capable of withstanding the severe ocean environment Offshore structures include ... Steel jacket structures Concrete gravity platforms Tension-leg platforms

Underwater Engineering - Learn the special requirements of living and working underwater Underwater concerns include ... Life support Work systems Cables, pipelines, shipwrecks, etc.

Environmental Engineering - Learn to protect the

oceans and seas from the harmful effects of

mankind's activities. Also learn to harvest and/or

utilize oceanic resources such as minerals, wave

energy, thermal energy and tidal power.

Environmental concerns include ...

Pollution abatement

Environmental remediation

Ocean resource utilization

The design of a structure or vehicle to

withstand the harsh environment of the

ocean or coast (due to waves, currents,

pressures, corrosion, etc.), is usually much

more complex than the design of that same

structure for land application.