CE707-Lec08-Layout and Functional Requirement of Port

8/19/2019 CE707-Lec08-Layout and Functional Requirement of Port

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Prof. Manasa R. BeheraDept. of Civil Engineering, IIT BOMBAY

Layout and Functional Requirement

for Planning and DevelopmentofCommercial Ports and Harbours

Site SelectionFollowingfactors need consideration:

a) Access – Rivers, canals, highways and railways.

b) Size a nd D epth – Adequate size of area, sea front and depth without excessive

dredging should be available

c) Physicaland TopographicalFeatures

1. Shelter ingfrom windsand oceanwaves

2. Subsoil conditions3. Dredging

4. Shoreline stability

5. Upland d rainage

d) Hydrographic and HydrologicalFactors

a) Tides

b) Current (< 4 knots)

e) MeteorologicalFactors

f) ConstructionMaterial

g) Strategic and SecurityConditions


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Harbour and Operational Facilities:a) Harbour Depth

b) Navigational Channel

c) Wind, Wave and Current

d) Harbour basin

e) Piers and wharves,

f) Storage areas and sheds and storage of hazardous cargo

g) Open storage area

h) Other functional and operational buildings

i) Roads and portrailways

j) Fire protection measures

D = D’+(H/3)+D” Dmin = D’ + (0.6 to 0.75 m)

where,

D’ = the draft of the largest ship to be accommodated

H = the maximum height of the storm waves

D” = the allowance for squat

Squat: The squat effect is the hydrodynamic phenomenon by which a

vessel moving quickly through shallow water creates an area of lowered

pressure that causes the ship to be closer to the seabed than would

otherwise be expected.

Squat effect α (the speed of the ship)2

Layout and Functional RequirementHarbour Depth


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Navigation Channel Alignment

The channel should be

- Straight as far as possible

- Located in areas of maximum natural depth

- Entrance to the harbour basin should be located on the lee side


Navigation channels or waterways can be divided into:

W

W > 10 B

B = beam of the largest ship to navigate at all state of tide

Navigation Channel Alignment

Curves and Bends:

For vessels without tug assistance – minimum radius > 3L up to 25°

> 5L 25° - 35°

> 10L beyond 35°

L – length of the largest vessel

Guide for radius of curvature

Rmin = 1200 m for ship less than 150 m long

= 2000 m for 150 long

= 2000 to 3000 m for 150 m – 210m long


Stopping distance:

Stopping distance is part of the navigation channel inside a harbour. It should be long

enough for ships to stop.

Minimum stopping distance = (7 ~ 8) L in loaded condition

= (3 ~ 5) L in ballast


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Water Depth in Navigation Channel

The water depth in the navigation channel, berth basin and in front of the berth

structure should be sufficient for safe manoeuvring of ships, where the nominal

water depth is the level above which no obstacle to navigation exist.

The rough guide for the minimum underkeel clearance is

UKC = (Depth of water + height of tide) – Static deep draft

bottomRock m0.1

bottommaterialSoftm5.0clearanceunderkeel Net

shipdesigntheof draftimummaxtheisD

area berthingotectedPr D15.0

area berthingExposedD20.0

channelExposedD25.0

areaseaOpenD30.0

clearanceunderkeelGross


Water Depth in Navigation Channel



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The minimum width of the navigation

channels primarily depend on the size of

the ships, type of the channel, wave,

current and wind characteristics.

shipdesigntheof widthbeamtheis B

lane Double B )0 .8to1 .5(

lane Single B )0 .5to3 .3( channel of Width

B )5 .1to75 .0( clearanceof Width

B )0 .2to8 .1( g manoeuvrinof Width

As a rule of thumb:

Layout and Functional RequirementWidth of Navigation Channel

TWO LANE CHANNELONE LANE CHANNEL

Layout and Functional RequirementWidth of Navigation Channel

Allowance due to currents

or cross wind


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Wind

For convenience of berthing, the berth line should be aligned as parallel as possible

to the prevailing wind direction.

Wind information is often expressed into the windrose diagram showing yearly

distribution of the wind directions and speed.

Wind intensity is expressed either by wind speed or by the Beaufort wind scale.

The mean wind speed and direction should be recorded 10m above the mean water

level in not less than 10 minutes.


WindRough operation guidelines for shipsGust ratio with respect to 1 hour

mean wind velocity

Duration (s) Gust Ratio

3 seconds 1.56

10 seconds 1.48

1 minute 1.28

10 minutes 1.12

30 minutes 1.05

1 hour 1



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Waves can enter into the harbour through the entrance by diffraction, through the

breakwater by penetration and overtopping.

The waves are normally the main cause of ship movement/instability.

Acceptable wave height inside harbour depends on

• the ship size

• Wave direction

• Wave period

It increases with the increasing ship size.

Waves against the ships can be classified into

• Head-on wave• Beam wave

• Quartering wave

Acceptable wave height is highest for the head sea and lowest for the beam sea

condition.

Layout and Functional RequirementWave

Wave

Effect of wave period

The wave periods also influence the general acceptability of wave heights

Fishing boats and small ships – short period waves (= 20 seconds) are dangerous



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Wave

Rough guideline for the acceptable significant wave heights inside harbours with wave

periods in the range of 7~12 seconds.


Currents

Currents can arise inside a harbour due to wind, tide, flow from river estuary, etc.

The magnitude and direction of current are important to evaluate any influence on the

berthing and deberthing operation of ships.

Limit of current speed for the large ship operation inside harbour

Visibility

Visibility is affected by fog, heavy rain and snow. In general, the visibility of 500 to 1000

meters is required for the ship operation inside harbours.



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Water Area:

Berthing area + Passage and manoeuvring area + Turning basin + Anchorage and

Offshore moorings

Layout:

The harbour receiving wide range of ships should be divided into at least two zones (one

for larger and the other for smaller ships).

Berths for dangerous cargo like oil and gas should be located at a safe distance and

clearance from other berths.

Dimensions and layout should be examined for short and long period resonance.

Turning basin should be located at the head of the navigation channel and central area.

Anchorage area should be close to the harbour entrance but well clear off the channel

traffic.

Layout and Functional RequirementDesign of Harbour Basin

Berthing area

Berthing area length: 1.1 L – 1.2 L or minimum 15m

Berthing area width: Minimum 1.15 B

Passage and manoeuvring area

Width : 2.0 L for berths at 90°1.5 L for berths at 45°

0.6 L for parallel berths


Anchorage and Offshore moorings

Using ships anchor and chain

R = 165 + 1.5L

Using mooring buoy

R = 1.5L + r

r = radius of swing of buoy


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Entrance:

The width of the entrance should be wide enough for navigation and narrow enough to

protect from waves.

Width of entrance =

100 – 150 m for medium vessels (up to 150 m)

200 – 250 m for large vessels

Thumb rule: (0.7 ~ 1.0) L; where L is the length of the design ship.

Where the entrance is between sloping breakwaters, the width should be measured for

the maximum draft of the largest vessel at bed level.

Turning area:

The turning area should be in the central area of the harbour basin. It’s size depends on

the time permitted for the execution of the turning manoeuvre.

Minimum diameter of turning area = 4 L Without tug boats

= 2 L With tug boats

Anchorage area:

The anchorage area is the place where ships can wait for

their turn at berth or for more favourable weather condition.

The size of anchorage area depends on: number, type and

size of ships also the type f mooring system available.

Water depth at an anchorage area should not exceed approx.

60 m due to the length of the anchor chain of the ships.

The bottom condition should not be too hard for the anchors

to stick in.



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Berthing area:

Where more than one ship has to be accommodated along the berth, a clearance of at

least 0.1 times the length of the largest ship should be provided between adjacent

ships.

Pier or Jetty Berthing:

It will provide more berthing spacethan quay type berthing.


L + 50 to 60 mThe length of pier or wharf meant for a

single vessel should be 50 to 60 m

more than the LOA of the design ship.

Width of Pier:

The minimum width of pier is decided on the basis of area required for transit shed,

number of railway tracks, truck lanes, apron width, etc.

Deck elevation:

The required deck elevation of cargo terminal is related to optimum position of cargotransfer equipment in two extreme conditions:

- Largest vessel in light DT at high water

- Smallest vessel loaded DT at low water

Minimum = HHWS + H/2 + clearance of 1 m.

Land area behind berth:

Depends on type of berth and cargo.

General cargo = 2.5 to 3.0 ha

Container berth = 8.0 to 12.0 ha



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Clearance from wharf edge:

Outer rail of the crane track shall be laid as far away from the quay edge as possible

without reducing the capacity of cranes to guard against damages likely to occur due

to vessels colliding with wharf cranes.

Minimum distance of quay edge inclusive of fixed fenders from the outer crane track

is 2.65 m.


Utility services:

Lighting : 5 lux in apron and 20 lux in working area

Water supply : 600 to 900 l/min @ 50 m from center line

Fuel supply : 100 to 150 tonnes/hr

Fire Protection:

- Non-combustible construction

- Automatic sprinkler, dry mains and fire hydrants

- Fire fighting equipment

- Fire Alarm

100 m c/c

- Water supply for fire fighting

4500 - 6000 l/min

- First Aid

- Proper maintenance of electric circuits and accessories.



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Thank you

Documents

CE707-Lec08-Layout and Functional Requirement of Port