PORTS Flashcards
What are the two main categories of water transportation?
Inland transportation and Ocean transportation
What is the estimated percentage of international trade carried out by shipping?
About 75 percent
A sheltered area of the sea for launching, building, or repairing vessels, or for loading and unloading cargo and passengers
harbour
What are the three classifications of harbours?
- Natural harbours
- Semi-natural harbours
- Artificial harbours
Natural formations affording safe discharge facilities for ships, such as creeks and basins
Natural Harbours
What factors have made natural harbours big and attractive?
- Local geographical features
- Growth of population
- Development of the area
Protected on sides by headlands with man-made protection only at the entrance
semi-natural harbours
Harbours constructed using engineering skills where natural facilities are not available
artificial harbours
A deep navigable channel with a protective natural bank or shoal to seaward natural roadstead
natural roadstead
A confined area naturally enclosed by islands, such as a creek
circumscribed natural roadstead?
What are the three major types of harbours based on their utility and situation?
- Harbours of refuge
- Commercial harbours
- Fishery harbours
List the requirements of a harbour of refuge
- Ready accessibility
- Safe and commodious anchorage
- Facilities for obtaining supplies and repairs
What are the requirements of a commercial harbour?
- Spacious accommodation for the mercantile marine
- Ample quay space
- Storage sheds for cargo
- Good repair facilities
What factors influence the accessibility and size of harbours?
- Location of the harbours
- Design of the harbour entrance
- Maximum dimensions adopted
What are the guiding factors in the choice of site for a harbour?
- Availability of cheap land
- Transport and communication facilities
- Natural protection from winds and waves
- Industrial development
What principles should be followed regarding the shape of the harbour?
- One pier head should project beyond the other
- Width inside pier heads should widen rapidly
- No re-entrant angles should be allowed
What should be studied during harbour planning?
- Thorough survey of the neighbourhood
- Borings on land for subsurface conditions
- Existence of sea insects
- Problem of silting or erosion
What is the difference between a harbour and a port?
A harbour consists of waterways and channels, while a port includes everything on the landward side of those lines
What are the classifications of ports based on location?
- Canal ports
- River ports
- Sea ports
What is a free port?
An isolated, enclosed area for handling cargo without customs intervention
List the classifications of ports based on commodities dealt with
- Grain ports
- Coaling ports
- Transhipment ports
- Ports of call
What are the requirements of a good port?
- Centrally situated for the hinterland
- Good tonnage
- Good communication
- Populous
- Capable of easy economic development
What natural phenomena affect the location and design of harbours?
- Coastal currents
- Tides and tidal range
- Wind and wave effects
What causes tides on the coastline?
The gravitational effects of the sun and moon
Tides that rise higher and fall lower during new and full moons
spring tides
Tides that rise and fall less than at other times, occurring about a week after new and full moons
neap tides
What are the two kinds of water waves?
- Waves of oscillation
- Waves of translation
A protective barrier constructed to enclose harbours and keep waters undisturbed
breakwater
What is the desirable alignment for a breakwater?
Straight converging arms with an intersection angle not exceeding 60 degrees
What are the three important rules in the design of a breakwater?
- Design based on extreme phenomena of wind and waves
- Height of the wave determined by specific equations
- Ensure foundation material is not subject to scour
List the detrimental forces acting on breakwaters
- Hydrostatic force
- External forces (wind and wave action)
- Solvent action of seawater
- Sea insects
What are the three types of breakwaters?
- Heap or mound breakwater
- Mound with superstructure
- Upright wall breakwater
A platform or landing place for ships to embark and disembark passengers and cargo
wharf
What is the difference between a wharf and a quay?
A wharf is generally an open structure of piles or posts, while a quay is typically a solid structure
What is the purpose of piers?
Structures built perpendicular or oblique to the shore for ships to berth
What is the purpose of bracing and bolting vessels?
To withstand impact from any vessel.
A structure built perpendicular or oblique to the shore of a river or sea
pier
Where are piers constructed?
In shallow waters where natural harbors are not convenient for ships to berth.
What materials are commonly used in the construction of piers?
Piles, columns, and braces.
What dimensions should a pier accommodate?
It should be long enough for the longest ship and wide enough for easy unloading of cargo.
Wharves along and parallel to the shore
quays
What are quay walls designed to do?
Retain and protect the embankment or filling.
List factors affecting the design of quay walls.
- Character of foundation
- Pressure due to water
- Effect of buoyancy
- Earth pressure at rear
- Weight of the wall
- Live load of vehicles
- Dead load of goods
- Force of impact of vessels
A structure built out from the shore to deep water
jetty
What is the primary function of jetties in rivers?
To divert the current away from the river bank.
How do jetties affect navigation in the sea?
They control navigation and provide access to ships.
A cushion provided on the face of a jetty for ships to contact
fender
What materials are commonly used for fenders?
Timber, coiled rope, springs, rubber, buffers.
Fill in the blank: The fender system controls the relative motion between dock and ship caused by _______.
[wind and waves]
What are the four categories of fenders?
- Rubbing strips
- Timber grill
- Gravity-type fendering system
- Rubber fendering
What is the purpose of navigational aids?
To guide mariners and their ships during navigation.
What are fixed light stations?
Light stations built on land or submerged outcrops.
A tall tower built to house powerful lighting equipment for navigation
lighthouse
What factors determine the visibility range of a lighthouse?
- Height above sea level
- Intensity or power of the light
What types of signals are used in navigation?
- Light signals
- Fog signals
- Audible signals
Small ships used to carry lanterns for navigation signals
light ships
A prominent object used to indicate and guide in navigation
beacon
Floating structures used for demarcation and navigation
buoys
Fixed-position buoys where ships can moor without anchors
mooring buoys
What are wreck buoys used for?
To locate wrecks in harbors or open seas.
What forms do fog signals take?
- Bells struck by hand
- Mechanically operated bells
- Whistles
- Sirens
What are audible signals used for?
To attract immediate attention of mariners in emergencies.
Fill in the blank: Sound transmitted through the air can give a misleading idea about the _______ of sound.
[direction]
