RAHE UNIT 5.pptx

Harbour is defined as place on the coast where ships are
anchored and it provide shelters from rough waters by piers, jetties
and other artificial structures.

 Port is a commercial harbour with all infrastructures.
 Major purpose of port is loading and unloading of cargos of
cargo ships.
 Located along coastal line where water is navigable and located
close to land and infrastructure facilities.

 An enclosed area of water in a port provided for the loading,
unloading and repairing of ships.
 It may be of dry or wet type.

WET DOCKS: Some minimum volume of water, the docking of
ship remains constant. The cargo ships are halted in wet docks for
loading/unloading and passenger ship for disembarking/embarking
of peoples.

The alternate rising and falling of the sea due to combined
gravitational attraction of sun and moon upon various parts of
earth, usually twice in a lunar day is called tide.
Types of Tides:-
Spring Tide :-These are highest tides which occur occur when
moon and earth fall in line.

 Waves are undulations caused on surface of water due to wind.
 Waves are of two types.
 They are waves of oscillation and waves of translation
Causes of Sea Waves :-
 Wind
 Revolution of the earth Gravitational force of the moon and sun.
 Earthquake
 Land slide and seashore.

Satellite port is a small port which is a subordinate to major
port and depends upon later for higher order facilities.

 Littoral drift is the process by which beach sediment is moved
along the shore line under the influence of waves and currents.
 Mud, sand or gravel material moved parallel to the shore line and
shoals, beaches, bars etc.,

The action of
measuring the
depth of a
water body is
called
sounding.

 Entrance Channel
 Break Water
 Turning Basin
 Shelter Basin
 Pier
 Wharf
 Quay

 Dry Dock
 Wet Dock
 Jetty

Entrance Channel: Water area from which ships enter in the
harbour and it should have sufficient width, 100 for small harbour,
100to160m for medium and 160 to 260m for large harbour.

REQUIREMENTS OF GOOD HARBOUR:
 The important requirement of any harbour is to enable arrival
and departure of the ships with least possible delay.
 The depth of harbour should be sufficient for every type of
visiting ships.

 The bottom of harbour should provide secured anchorage to hold
the ships against high winds.
 To prevent destructive wave action, break waters are provided.
 The entrance of harbour should be wide enough for easy passage
of ships

The other important requirements of harbour are,
a)Shelter
b)Accommodation
a)Shelter
Harbours should provide essential safety to ships against rough
seasons and violent sea.

 Ships may have to shelter for many days of year when it is not
possible to load or unload them.
 Sometimes for safety of ships, they are brought out of harbour
b)Accommodation
 Opportunities and facilities required for trade operations.

 Convenient and continuous accessibility of ships for loading and
unloading of goods and embarkation and disembarkation of
passengers.
The following are some examples
i)Quays to berth ship alongside.
ii)Sheds and warehouses to temporarily deposit goods.

iii)Cranes and appliances for handling goods.
iv)Service roads and railway tracks.
v)Repairing workshops
vi)Passenger facilities

CLASSIFICATION:
i)Primary Classification
a)Natural or land locked harbours
b)Protected harbours
c)Artificial harbours

a)Natural harbours:
 Formed entirely by inlets from sea.
 Constituted by headlands or projecting parts of a coast
converging towards each other.
 They have narrow entrances leading to a sheltered area of water
and deep enough to furnish anchorage.
 Some natural harbours are Bombay, Sydney etc.,

b)Protected Harbours
 Partly natural and partly artificial.
 Formed primarily in bays or such position in coastal line.
 Artificial construction of break waters or entrance moles along
with existing natural features forms a protected harbour.
 Vishakapatnam harbour is a protected harbour.

c)Artificial Harbours:
 Created where there are little or no pronounced natural features.
 Break waters are constructed on open coastal line.

ii)Subsidiary Classification:
a)Roadstead
b)Harbours of refuge
c)Naval harbours and bases
d)Commercial harbours
e)Fishing harbours

The basic objective of any harbour should be given due
consideration. They are
i)Obtain a large area of deep water during all the seasons
and at all states of tides.
ii)To give shelter to ships from rough seas.

iii)To provide adequate space for free movement and for resting of
ships and for their swing actions.
The important factors to be considered in site selection for harbour
are,
i)Speed of sea water
ii)Amount of dredging required in a particular location
iii)Tidal range

iv)Range or Seiche
v)Wave characteristics- length, height and velocity
vi)Incidence and magnitude of storms
vii)Direction and Velocity of wind.
viii)Shore considerations
ix)Geological characters

x)Soundings
xi)Shoals
xii)Tidal currents
xiii)Hinterland characteristics
xiv)Hard land and coast line
xv)Anchoring grounds

i)Speed of Water:
 Neither too excessive nor too low.
 If speed is low, it silts an area.
 If too fast, it erodes harbour and channel areas.
 Speed of water has to be studied during different seasons over
year.

ii)Dredging:
 Amount of initial dredging and amount of maintenance dredging
should be lesser.
 Important factor in siting an artificial harbour in view of cost
factor.
 More important when position lies in an estuary of river upon a
coast subject to coastal changes and littoral drift.

iii)Tidal range:
 Range of tide at site has great influence.
 Ships can be loaded and unloaded at quayside berths or wharves,
if tide does not exceed 5.5m.
 If tide exceeds this value, it is necessary to provide enclosed
harbour with lock entrance.

 Such harbours are expensive.
 It is important to select site with minimum tide range.
 Detailed investigation should be done.
iv)Range or Seiche:
 Seiche is a standing wave in a sea.
 It is caused by change in atmospheric pressure or seismic
differences.

 It produces lateral oscillation of water.
 Even a moderate scale of seiche in harbour constitute a serious
hazard to shipping.
 It causes disturbance to loading and unloading operations .
 Incidence and magnitude of seiche is estimated from data
available and studied with a help of scale model.

 Information from models can help in determining shape of
harbour and layout of break water.
 Entrance has to be modified to reduce or eliminate seiche.
 A site should be selected taking in to consideration incidences of
seiche.

v)Waves and their characteristics:
 Study of waves is important.
 Frequency and magnitude of storms and direction and velocity of
maximum and prevailing winds should be taken in to account.
 Waves affects the form and design of break waters.
 Pattern of site, shoaling, shallowness and beach building depends
up on waves.

vi)Incidence of Storms:
 Water transport is susceptible to storms and cyclones.
 Frequency and magnitude of storms affects the location, form
and design of harbours to some extent.
 Past data on storms should be studied.
 Sites susceptible and vulnerable to storms is not a desirable one.

vii)Wind Characteristics:
 Wind causes waves.
 Velocity and height of waves depend upon the direction, duration
and intensity of prevailing winds.
 Waves of greater height and velocity have severe impact on the
efficiency and economy of port.

 Wind data plays a vital role in site selection of harbour.
 Wind data collected for 10 years is studied and analysed and
harbour location is decided.
viii)Shore Considerations:
 Proximity to towns, roads and railways, water supply and
availability of suitable rock supplies are shore considerations.

 Otherwise, facilities have to be created exclusively for proposed
harbours.
 Transportation of rocky materials from distant locations are
costlier.
 Old charts are compared with latest charts and information are
obtained regarding alteration in coastal line, beaches and
positions and size of shoals.

ix)Geological Characteristics:
 Safety and adequacy of any maritime structures depends upon
the geological pattern of the region.
 Nature and depth of various strata and other considerations such
as geological formations, types of rock, seepage flow etc., are
important in locating harbours.

 Geo physical methods are used to explore geological
characteristics of the site.
x)Sounding:
 Measuring depth of sea.
 If minimum depths are not available, bottom of ships may rock
on sea beds with disastrous consequences.

 Depending on size of ships, minimum depth may range between
6 to 10 metres.
 Echo sounders are used for this purpose.
xi)Shoals:
 Sandy elevation of bottom of body of water.
 Sand bank or sand bar.

 These are hidden
dangers and
destructive if they
present in and
around proposed
sites for harbours.

 Study of position and size of shoals is a critical one.
xii)Tidal Currents:
 Caused by earth quakes on sea beds.
 Cause greater damage to stability of structures.
 Direction and velocity of tidal currents are studied with greater
accuracy and accordingly sites are chosen.

xiii)Hinterland characteristics:
 Hinterland is a area served by port.
 Location of port should be placed where adjacent areas are
densely populated with sufficient industries and fertile land to
ensure sufficient traffic.

xiv)Hard Land and Coast Line:
 Hard land surface and coast line will not permit easy erosion of
shore and will not require many repairs.
 If coast is of sandy soil, intermittent repair of docks and port will
make maintenance expensive.
 So site with hard land and coast line is preferred one.

xv)Anchoring grounds:
 Anchor is a heavy object made of iron and lowered by cable or
chain to keep ship from drifting.
 Good and safe anchoring ground is a pre-requisite for location of
harbours.

PLANNING AND DESIGN OF HARBOURS:
 First step is to survey the surrounding area.
 Based on survey, a chart indicating depth of water in vicinity is
prepared.
 Soil profile, geological characteristics and fitness for anchorage
are ascertained from survey.

 Engineers plot land and marine contour lines, analyze available
data and interpret various and natural and metrological
phenomena.
i)Special Considerations:
a)Direction and intensity of winds.
b)Frequency of storms
c)Height and force of waves
d)Field range and velocity of currents

e)Littoral drift, erosion, silting
ii)Design elements in planning of harbours:
a)Area for free movement and depth
b)Harbour entrance
c)Entrance channel
d)Light house

e)Sufficient parking, loading and unloading space
f)Characteristics or ships influencing harbour design

Terminal Facilities:
Terminal facilities are essential and indispensable
requirements of harbours. The facilities to be provided are,
i)Feeder transport service
ii)Coastal structures- Quays, Jetties and Break waters
iii)Transit sheds and warehouses

iv)Appliances and equipment's for handling cargo
v)Repair shops and ancillary services
vi)Dredging equipment's
vii)Mooring accessories
viii)Navigational aids
ix)Cold storage facilities
x)Other services.

 Enclosed area provided in a port for loading, unloading and
repairing of ships.
 Enclosed by gates or otherwise.
 The principal function of harbour are execution of repairs,
cleaning and painting of ships.
 So docking arrangement should expose ship’s exterior fully and
 keep it out of water during repair and renovation.

Types of dock are,
a)Graving or dry dock
b)Floating dry dock
c)Wet dock

a)Dry Dock:
 It is a long excavated chamber having side walls, a semi circular
end wall with a floor.
 Open end is provided with gate and act as entrance to dock.
 Side walls are provided with steps to support vessels in vertical
position.

 Dock is constructed of concrete masonry and steps are of granite
to withstand heavy wear.
 Floor is made of concrete and is very heavy.
 Keel and block are fixed on floors on which ship is brought to
rest.
 Floor has cross fall to drain the water.
 Other accessories required are big capacity pumps, lifting and
hoisting machines and repair equipment's.

 Water level inside the dock are adjusted to water level outside.
 Ship enters in to dock and gates are then closed.
 Powerful pumps will drain out water and ship is lowered on to
keel.
b)Floating dry dock:
 It is a floating vessel.

 Can lift ship out of water by its own buoyancy.
 Consists of hollow structure of steel or concrete with two side
walls and a floor with open ends.
 To receive ship, the whole structure is sunk in to water to
required depth.
 Chambers will filled with water.
 Ship is then floated in to position and berthed.

 Dock is raised
along with
berthed ship
and water is
pumped out of
chamber.

c)Wet Dock:
 Minimum depth for ships should be ensured.
 So dock system requires entrance locks with massive gates
operated by machinery.
 If rise and fall of tide is generally considerable raising up to 15m
between low and high waters, gates have to be provided to
impound water between successive periods of high and low
water.

 Impounding of water helps to maintain level naturally and
separates dock from outer water way , unless levels of outer and
inner water coincides.

The advantages of having wet dock for berthing are
a)Uniform level of water is maintained.
b)Rubbing of ship against quay wall is avoided.
c)Disturbance in open sea do not have any effect on the
working of dock system.

MOORING ACCESSORIES:
Devices provided for anchoring arrangement, where
anchorage water area is limited.
Moorings are of two types,
i)Fixed
ii)Floating

i)Fixed mooring:
 Fixed mooring consists of bollards, ropes and posts.
 Secure ship against swaying of winds and waves.
 Bollards are designed to take up pulls up to 35 tonnes.
 They are fastened on concrete deck by galvanised bolts passing
through pipe sleeves set in concrete.

ii)Floating mooring buoys:
Consists of buoys of various shapes anchored to bottom of basins
or bed of rivers.
Different types are,
a)Pear shaped
b)Barrel or cylindrical
c)Drum and
d)Spherical

Safe and speedy navigation with coastal water depends upon
establishment of number navigational aids of various types.
a)Need for aids
i)Warn ship masters of rocks, shoals and banks
ii)Assist in safe movement of ships within restricted
navigable sea approaches, rivers, channels and entrances and ports.

iii)Indicate location of ports and harbours.
b)Requirements of navigational aids
i)They should be easily identifiable and made with
international standards.
ii)Long range of visibility.

c)Types of navigational aids:
Three types of navigational aids are
i)Fixed navigation aids
ii)Fixed navigation markings and lights on harbour and dock
entrances, piers and pier heads, wharfs, cables.
iii)Floating beacons usually termed as buoys which emit light,
sound or radar signals or merely be distinct-in shape and colouring

 Light house is constructed as warning light stations in high seas
for safe navigation.
 It is a huge structure, the lower portion is used for residence and
maintenance of staff including storage of provisions and water.
 Top floor contains light source and floor immediately below
contains equipment for lighting and operating machinery.

 Light house is located on good rock or hard soil.
 A thick bed of concrete is provided as foundation.
 In marshy locations, caisson or pile foundation is used.
 Structure is constructed using good stone or brick masonry or of
concrete blocks.
 RCC construction is used from foundation to top in some cases.

 Tower is divided into
number of floors.
 Geographical range of
light houses along with
luminous range of light
source determines
height of the tower.

Types of light signals are,
a)Beacons
b)Light ships
c)Floating buoys

 Piers
 Break waters
 Jetties
 Quays
 Spring fenders

 A plat form supported on
pillars, leading out from
shore in to a body of water
and used as landing stage
for boats or fishing.
 A Piers can also function
as break water.

 A barrier built on to body of water to protect a coast or harbour
from the force of waves.
 Its function is to break up and disperse heavy seas.
i)Methods of reducing wave action:
a)If a wall of sufficient height and strength is constructed,
waves will be totally reflected . In shallow water, waves are
partially destroyed by wave breaking.

b)If waves are made to run up along sloping beach, their energy is
absorbed gravitationally
ii)Classification of break water
a)Wall of masonry or concrete blocks or mass concrete
b)Mound of rubble stone
c)Subsidiary classes of break waters

 It is a structure which reflects and dissipates the forces of wind
generated waves.
 Encloses harbour and keep the harbour waters undisturbed.
 It provides safe anchorage for ships
 Facilitate loading and unloading of cargo in comparatively calm
water
 The inside of a breakwater when constructed as a quay for
handling cargo then it is known as a mole.
 The function of break water is to break the momentum of water
by means of wave breaker.

 Wide stone walls built along edge or out in to sea or river, where
ships can be tied up to unload goods.
 It is a structure for berthing purpose slightly distinct from quay.
 It is constructed of piles and framing instead of solid masonry or
concrete.

 Jetties are landing spaces provided as projected structures built
out in to deep water from shore.
 Structures in harbours which performs duties of loading and
unloading platforms with breakwaters is also termed as jetties.
USES:
 Berthing of vessels at head or alongside.
 Used for loading and unloading and break water.

LOCATION:
 Usually located in sheltered position inside harbour or wet docks
where vessels are manoeuvred in still water safely.
 May also situated in wide navigable rivers, estuaries and bays,
where they are exposed to wind and waves and increased hazard
conditions when ships are berthed alongside.

TYPES:
i)Piled or Open
-Timber
-Steel
-RCC
ii)Solid Type

 A stone or metal platform lying alongside or projecting in to
water for loading and unloading ships.
 Quays are parallel to coast normally and made up of monolithic
structures.

Fenders are objects such as mass of rope, an old tyre and
lump of wood that hangs over side of boat of boat to protect it from
damage by other boats or when coming to land.
ROPE FENDER

 R.C Jetties and wharves are covered with timber work bolted to
structure.
 This timber work prevents concrete from damage but not
effective from impact absorbing point of view.
 Three general ways in which efficient impact fending can be
provided are,

i)Separate timber dolphin and intermediate timber work
independent of structure.
ii)Some form of resilient buffer is created between tops of dolphin
and structure. Such buffers may be coil or rubber or steel springs
etc.,

iii)In fulcrum system, fenders are suspended in such a manner that
the force required to push them out of original position is sufficient
to bring vessel to rest by absorbing kinetic energy of latter.

Different Ways of Fending:
i)Simple fending:
 Separate piles are driven in front of structure with systems of
walling and verticals.
 Ensures safety of ships.
 Timber fender walling and verticals are bolted direct to the
structure,

 Berthing of ships is comparatively easy.
 Inefficient for berthing of vessels of 10,000 tonnes and upwards.
 Damages occurs frequently.
ii)Spring Fending:
 More appropriate in open water or tidal waters.
 Provided for absorbing kinetic energy and for limiting travel of
vessels after impact.

 Design for approach speed of 46cm/sec or approximately one
knot.
 Fenders were made of pyinkado cased in steel and hinged at the
bottom to brackets on main pile of timber jetty.
 Three sets of springs are used.
 Each requires a load of 30 tonnes for full compression.

 Coastal structure extends above water level and not connected to
shore.
 It is a cluster of piles.
 It is used for berthing or mooring of ships, when length of ship is
greater than berth or pier provided.
 Information's like speed limit, direction etc., can be displayed in
dolphins.

 Consists of number of piles
driven in to sea bed and
connected above water level
to provide a platform or
fixing point.
 Tankers of 15,000 tonnes can
be berthed.

 Shipping traffic along
country’s coast.
 Preferred mode of
transport from economic,
energy consumption and
environmental point of
view.

 Indian has about 14500 km of navigable and potentially
navigable waterways.
 Government is trying to improve inland water transport by
creating right policies and fiscal environment.
 A parliamentary standing committee on Transport, Tourism and
culture has recommended 10,500 crore investment for
developing inland water transportation.

 Containerization is the use of containers to unitize cargo for
transportation, supply and storage.
 Ports, railways, roads, warehouses, shipping and logistic
companies are primary players dealing with containers and
contributors to development of container trade and infrastructure.

ADVANTAGES:
 Effective handling of cargo.
 Minimal or no damage to goods.
 Optimum utilization of storage and warehouse capacity.
 Technology adoption due to mechanized handling required
handling containers.

 Reduction in transport time.
 Door to door or end to end delivery of goods.
 Effectiveness in supply chain mechanism in trade.

 Marine surveying is process of conducting inspection, surveys or
examination of marine vessels to assess, monitor and report on
their condition, damages and their sea worthiness.
 Marine surveys include structure, machinery and equipments
(navigational safety, radio etc.,) of vessel.
 Done by Marine surveyor.

MEAN SEA LEVEL (MSL):
 Mean sea level or Sea level is the average height or elevation of
sea surface.
 Sea level halfway between mean levels of high and low water.
Measuring Sea Level:
 Level of sea is continuously changing.

 In matter of seconds, waves can raise and drop the level of sea
by several metres.
 Tides can also raise or lower level of sea when there is change in
pressure or wind.
 In order to average out the fluctuation caused by waves, tides,
wind, periodic measurement of sea level over at least 19 years
are averaged to determine mean sea level.

 Suction
 Trailing suction
 Cutter Suction
 Auger suction
 Air lift
 Jet lift
 Bucket type

Inland water navigation takes place on three basic types of
channels. They are,
 Rivers and lakes
 Channelized rivers
 Artificial canals
 Rivers and lakes follow a natural course and do not require
human efforts to stabilize the banks and beds.

 The channelized river require major work to make it as
navigable.
 The types of improvements needed includes,
Straightening of channels
To protect river beds and shores from erosion
Control water seepage
 Artificial canals are man-made waterways and should be most
easily and economically constructed and maintained.

 It involves the following,
DETERMINING EXISTING CONDITIONS:
 Area to be affected
 Character of existing and proposed effluents
 Existing water quality
 Existing flora and fauna
 Qualitative and quantitative uses of water

PREDICT FUTURE EFFECTS:
 Relate future changes in water quality to aquatic species
 Relate the future changes in water quality to economical and
social considerations where feasible.
PRESENT SOURCE COMMITEMENTS:
 Identify and evaluate any irreversible commitment of resources.
 Ex: Losses of use, cost of controlling adverse environmental
impact.

 The coastal protection works prevent the natural processes of
erosion and deposition.
 It prevents the damage to land and properties to adjacent to the
coasts.
 The coastal works are subjected to active earth pressure on one
side and wave thrust on the other.

PROHIBITED ACTIVITIES:
 Setting up or expansion of industries near sea shore
 Disposal of hazardous substances
 Discharge of untreated waste from industries
 Dumping waste from thermal station
 Altering of natural features including landscape….etc……

Category 1:
 Areas that are ecologically sensitive and important such as
marine parks, coral reefs, areas rich in genetic diversity…..
Category 2:
 Areas that have already developed up to shore line..

Category 3:
 Areas which do not belong to category 1 and 2. These include
coastal zones in rural areas and also with municipal limits which
are not substantially built up.
Category 4:
 Coastal stretches in Andaman, Lakshadweep and small islands
except Category 1,2,3.

Norms for regulations of Activities:
 Category 1: No new construction is permitted within 500 m of
high Tide Line.
 Category 2: Buildings permitted shall be subject to existing local
town and country planning.

 Category 3: Area up to 200 m from high tide line marked as “No
development Zone”
 Category 4: Dredging in and around coral formations are not
permitted.

RAHE UNIT 5.pptx

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RAHE UNIT 5.pptx