Transportation Engineering

1. TRANSPORTATION
ENGINEERING-II
HARBOUR’S & Dock’s

2. Defination of Harbour
A harbour is an area of the sea at the coast which is partly enclosed by land or strong
walls, so that boats can be left there safely.
"A harbour can be defined as a basin or haven or road-stead of navigable waters well
protected naturally or artificially from action of wind and waves, and is situated along
sea-shore, river estuary, lake or canal connected to sea“

4. Harbour Contd.
• Basin:- water reservoir of required areaNavigable when
depth of water in the basin is greater than draft required
for largest ship likely to visit the harbour.
• Draft:-Vertical linear immersion of the ship below the
water surface for the ship to float in a stable condition.
• Min. vertical clearance for safe floating

5. Requirements of a Harbour
The basic requirements of a harbor are:
•Sufficient depth should be available for the draught of
ships using the harbor.
•Anchorage should be sufficient in the bottom area of
harbor during high wind times.
•Protection against waves should be adequate

6. Site Selection for a Harbour
If natural formations of harbor are not available then it is essential to build artificial harbor. But
the site selected for a harbor should be based on some important factors such as:
• Marine conditions should be mostly favorable without any disturbances.
• The foundation soil or sea bed is properly checked whether it is capable to bear breakwaters
against wave and other forces.
• If there are Natural formations like mountains or island, then it is better to select a site nearer
to that area.
• Site should be economical and construction material should be easily available.
• Water should be fresh without any pollution.
• Surrounding area should be developed with factories and industries, then exports and imports
of goods will takes place highly.
• The harbor should be easily reachable.
• The area of harbor should be large. Generally, it is decided on the basis of accommodation for
number of ships.

7. Classification of Harbour’s
1. Classification depending upon the protection needed.
2. Classification depending upon the utility.
3. Classification based upon thelocation.
 Harbours are broadly classified as:-
1. Natural harbours
2. Semi-natural harbours
3. Artificial harbours.

8. Natural Harbour
 Natural Harbour is a water body protected by natural or artificial obstacles.
 Harbors can provide secure anchorage and allow ship-to-shore transfers of cargo
and passengers. ...
 Examples of natural harbors include the Sri Lankan port of Sydney, Australia, and
Trincomalee

10. Natural Roadstead
 A roadstead is a body of water sheltered from rip currents, spring
tides, or ocean swell where ships can lie reasonably safely at anchor
without dragging or snatching.
 It can be open or natural, usually estuary-based, or may be created
artificially

12. Semi-Natural Harbour
Semi natural harbors are also formed
naturally, but sometimes at the harbor
entrance manmade constructions are
required for more protection against winds
and waves.

13. Artificial Harbour
Artificial harbour or man-made harbours
does not contain any natural protections
and these protections are built artificially
which are called breakwaters. Breakwaters
are the structures which prevent the inside
water from storms and waves and keeps the
inside water still.

14. Types of Harbours based on Location
The harbours classification based on location are:
 Sea harbour
 River harbour
 Canal harbour

15. Types of Harbors based on Location
Sea Harbour
Harbor situated along sea
shore is termed as sea
harbor. Sea ports are of very
large area and loading and
unloading of goods also
done in larger quantities.
Different countries are
connected by these ports.

16. River Harbour
River harbours are
constructed in the rivers
which finally connects to
sea. So, these enable the
navigation inside a country
from noncoastal areas.

17. Canal Harbour
Canal harbours are
also similar to river
harbours but a canal
is connected to sea
through a major
river.

18. Types of Harbor based on Usage
The harbours are classified into five type based on usage as follows
 Commercial harbour
 Fishery harbor
 Military harbor
 Marine harbor
 Harbors of refuge

19. Commercial Harbour
Commercial harbours are those
where loading and unloading of
cargos are done. Commercial
harbor requires larger area for
speed up the operations and it is
the busiest among the others.
Some commercial harbours are
limited to loading and unloading of
single commodities like coal, crude
petroleum etc. only. The repair
works can also be carried out here
but they should be quick.

20. Fishery Harbour
Fishery harbours are
specially meant to cargos
carrying seafood or
aquatic animals. They are
always opened to fishing
ships for loading and
unloading. For preserving
the sea food sufficient
space is provided near
harbour.

21. Military Harbuor
Military harbours are used as naval
bases, where war ships are rested while
there is no work in the sea or during
repair works. No other private ships
should not enter this without
permission.
Some large military naval vessels can
carry aircrafts so, very large area of
harbor is required because of large
vessels.

22. Marina Harbour
Marina harbours are small harbours
where moorings are provided for yachts
and small ships. They are not suitable
for large cargos. The boats, ship repair
works, fueling are done in this harbor.
For transferring trailered boats into the
water slipways are provided at the
marina harbours.

23. Harbours of Refuge
A large area harboUrs which are useful
to shelter the ships during emergency
situations like storms or any other
natural calamities.
Harbours of refuge are constructed with
large entrance and they are easily
accessible. They provide good
Anchorage to the vessels against storms
and tides.

24. DOCKS
Docks are enclosed areas for berthing the ships to keep them afloat at a uniform level to
facilitate loading and unloading cargo. A dock is a marine structure for berthing of vessels
for loading and unloading cargo and passengers. Docks are necessary for discharging of
the cargo as ships require a number of days for discharging cargo, during which period
they need a uniform water level. If ship is subjected to a vertical movement by the tides,
great inconvenience will be felt in lifting the cargo from the ship and special arrangement
will be needed for lifting the cargo

25. Classification of Docks
Docks can be classified into following two categories:
 Wet docks.
 Dry docks.
Wet docks: Docks required for berthing of ships or vessels to facilitate the loading
and unloading of passengers and cargo are called wet docks. These are also known
as harbor docks.
Dry docks: The docks used for repairs of ships are known as dry docks.

26. Shape of docks and Basins
Shape of dock or basin should be straight to facilitate the ships to
stand along them, as curved shape is not convenient for ships to
stand along side. The shape of docks and basins should be such
that maximum quayage i-e berthing length is available within the
given area. The shape has therefore essentially to be made up of a
number of straight patterns as curved lines are unsuitable for
berthing of the ship.

27. The following are the shapes may be adopted as per site
conditions:
• Rectangular dock .
• Diamond dock .
• Inclined Quay type.
Rectangular dock:The length and breadth should be adjusted in
such a way as to give maximum quayage
Diamond Dock: For the same perpendicular distance between long
sides, the long side could be extended conveniently. Inclined Quay
dock: It consists of a number of projecting quays into the dock or
basin.

28. Classification of Dry docks
Dry docks are classified in the following five categories:
 Graving or dry docks.
 Floating dry dock.
 Marine railway dock.
 Ship lift dry docks.
 Slip ways.

29. Dry or graving dock:
A dry dock is also known as graving
dock. It is long excavated chamber,
having side walls, a semi circular end
wall and a floor. The open end of the
chamber is provided with a gate and
acts as the entrance to the dock.

30. Floating dry dock:
It may be defined as a floating vessel, which
can lift ship out of water and retain it above
water by means of its own buoyancy. It is a
hollow structure made of steel or R.C.C
consisting of two walls and a floor with the
ends open.
To receive a vessel or ship for repair, the
structure or floating dock is sunk to the
required depth by filling water known as
ballasting in its interior chambers and the
vessel is then floated into position and berthed.
The dock is raised bodily with the berthed
vessel by un ballasting the chambers by
pumping out the water. The earliest floating dry
docks resembled the shape of ships.

31. Marine railway dock:
The marine railway or slip dock or slip way is an
inclined railway extending from the shore well
into the water as the off there. This railway track
is used to draw out a ship needing repair out of
the water. Components of a marine dock.
The essential parts of a marine dock are as
follows:
Cradle.
Track.

32. Cradle:
The cradle or platform is constructed of
steel and moves up and down on an
inclined track. The cradle is mounted on
a system of rollers which move on the
iron tracks laid on longitudinal timbers.
These beams resting on piles and other
firm foundations.
Track:
The track consists of heavy rail sections
secured to longitudinal sleepers
supported on cross ties and laid at
inclination varying from 1/12 to 1/25,
usually an inclination of 1/15 is found
convenient and useful.

33. Lift dry dock:
This is a constructed platform capable of
being lowered into and raised from water.
Lowering and raising is achieved by means
of hydraulic power applied through
cylinders supporting the ends of cross
girders carrying the platform.
Ship lifts:
As the name suggests, in the ship lift, the
ships are lifted bodily out of water. The ship
lifts may be either electric, hydraulic or
pneumatic. These lifts are used for launching
as well as for dry docking the ships. Their
main advantage is the ease in adaptability to
transfer system enabling multiple garaging
of ships.

34. Slipways:
This technique is used for repairs as
well as for building of vessels. In its
simplest form a slip way consists of a
inclined path of timber or stone laid on
on a firm ground. On this inclined path
a series of rails are fixed. The rails run
up from a sufficient depth of water to
the required height above the high
water level to a point at which the
longest vessel to accommodated is
completely out of range of tide. The
lower end of slip is tidal and open to
water.

35. Thank you