The structure which are built
perpendicular to the shore of a sea are known
as piers In the sea, the piers are constructed
where the sea is not deep and the natural
harbour is not convenient for allowing the ships
to berth adjacent to the shore. In many cases,
the piers are constructed with piles, columns
and braces leaving good space for the ocean
current to flow without causing any
5. Pier heads-
A pier head is at the entrance to a harbour
and as it is expose on three sides, it is subject to
more shock than a breakwater.
The landing places or platforms built near
shore for vessels to berth are known as
wharves. Thus, a wharf affords a working
platform alongside the ship in continuity of the
The level of wharf should be above the
high water level, but at the same time, it
should be economical to load the vessels when
the water level is low.
These are structure in the form of pilled
projections. They are built from the shore to
the deep water. They may be constructed in
the sea or in a navigable river.
In the sea, jetties are provided where
harbour entrance is affected by littoral drift or
the sea is shallow for a long distance. The
jetties extend from the shore to the deep sea
to receive the ship.
10. Difference between wharf and jetty-
A started earlier, a jetty is a piled
projection from shore to deep water to berth
vessels along side. Some times a piled
projection parallel to the shore is called a wharf.
Thus we may say that a jetty differs from a
wharf as follows:
a)The wharf is a berth parallel to the shore,
where as a jetty is perpendicular to the shore
or break water.
b)The wharf has berth on one side only as it has
a back fill of earth. A jetty may have berths on
1. Docks are enclosed areas for berthing the
ships to keep them afloat at a uniform level
to facilitate loading and unloading cargo.
2. A marine structure for berthing of vessels for
loading and unloading cargo and passengers.
3. Necessary for discharging of the cargo
4. As ships require a number of days for
discharging cargo, during which period they
need a uniform water level.
12. 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
Docks can be classified into following two
13. 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.
15. Dry docks
• The docks used for repairs of ships are known
as dry docks.
• 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.
17. Different Mooring Accessories-
Following are the accessories for a fixed type
1. Mooring Port-
For bringing the ship in to the dock, corner
mooring ports are provided they are attached to
the corners of a pier or at the ends of a wharf.
18. 2. Bollard-
These are the thick posts designed to take
up pulls up to 35 tonnes or 350KN. They may be
provided either by single bit or double bit.
19. 3. Caspton-
It is an apparatus consisting of an up right
cylinder around which cables are wound either
by hand or machinery. These are helpful when
the rope lines to be handled are long and large.