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Periodic surveys by Classification Societies in maintaining cargo ships standard
Requirement of Periodic surveys
To maintain the assigned class all steel ships are required to be surveyed and examined by the Society’s
surveyors at regular periods.
The major hull items to be examined at these surveys only are discussed
here.
Annual Surveys
Annual surveys are applicable for all steel ships. These annual surveys are where practicable
held concurrently with statutory annual or other load line surveys. At the
survey the surveyor is to examine the condition of all closing appliances
covered by the conditions of assignment of minimum freeboard, the freeboard
marks, and auxiliary steering gear particularly rod and chain gear.
Watertight doors and other penetrations of watertight bulkheads are also
examined and the structural fire protection verified. The general condition
of the vessel is assessed, and anchors and cables are inspected where
possible at these annual surveys. Dry bulk cargo ships are subject to an
inspection of a forward and after cargo hold.
Intermediate Surveys
Instead of the second or third annual survey
after building or special survey an intermediate survey is undertaken. In
addition to the requirements for annual survey particular attention is paid
to cargo holds in vessels over 15 years of age and the operating systems of
tankers, chemical carriers and liquefied gas carriers.
Docking Surveys
Ships are to be examined in dry dock at intervals
not exceeding 2˝ years. At the drydocking survey particular attention is
paid to the shell plating, stern frame and rudder, external and through hull
fittings, and all parts of the hull particularly liable to corrosion and chafing,
and any unfairness of bottom.
In-Water Surveys
In water survey (IWS) – The survey of hull plating undertaken in the water. The ship is
provided with marks placed on the shell to show borders of tanks, cofferdam etc. Hull
plating should be cleaned by a diver-operated machine. A remotely-operated underwater
TV camera is used to view the ship plating.
IWS can be also applied for checking that the seal assembly on oil lubricated stern tube
bearings is intact and for verifying the clearance or wear-down of the stern bearing. For
that, an opening in the top of the seal housing and a suitable gauge should be provided
for checking the clearance by the divers.
The Society may accept in-water surveys in lieu of
any one of the two dockings required in a five-year period. The in-water
survey is to provide the information normally obtained for the docking
survey. Generally consideration is only given to an in-water survey where a
suitable high resistance paint has been applied to the underwater hull.
Special Surveys
Steel ships may be subject to special surveys as required by various classification society rules. These surveys become due at five yearly intervals,
the first five years from the date of build or date of special survey for classification
and thereafter five years from the date of the previous special survey.
Special surveys may be carried out over an extended period commencing
not before the fourth anniversary after building or previous special survey,
but must be completed by the fifth anniversary.
The hull requirements at a special survey, the details of the compartments
to be opened up, and the material to be inspected at any special
survey are listed in detail in the Rules and Regulations .
Special survey hull requirements are divided into four ship age groups as
follows:
1. Special survey of ships—five years old
2. Special survey of ships—ten years old
3. Special survey of ships—fifteen years old
4. Special survey of ships—twenty years old and at every special survey
thereafter.
In each case the amount of inspection required increases and more
material is removed so that the condition of the bare steel may be assessed.
It should be noted that where the surveyor is allowed to ascertain by drilling
or other approved means the thickness of material, non-destructive
methods such as ultrasonics are available in contemporary practice for this
purpose. Additional special survey requirements are prescribed for oil
tankers, dry bulk carriers, chemical carriers and liquefied gas carriers.
When classification is required for a ship not built under the supervision
of the Society’s surveyors, plans showing the main scantlings and arrangements
of the actual ship are submitted to the Society for approval. Also
supplied are particulars of the manufacture and testing of the materials of
construction, together with full details of the equipment. Where plans, etc.,
are not available, the Society’s surveyors are to be allowed to lift the relevant
information from the ship. At the special survey for classification all the
hull requirements for special surveys (1), (2), and (3) are to be carried out.
Ships over twenty years old are also to comply with the hull requirements of
special survey (4), and oil tankers must comply with the additional requirements
stipulated in the Rules and Regulations. During this survey the
surveyor assesses the standard of the workmanship, and verifies the scantlings
and arrangements submitted for approval. It should be noted that
the special survey for classification will receive special consideration from
Lloyd’s Register in the case of a vessel transferred from another recognized
Classification Society. Periodical surveys where the vessel is classed are subsequently
held as in the case of ships built under survey, being dated from
the date of special survey for classification.
Damage Repairs
When a vessel requires repairs to damaged equipment or to the hull it is
necessary for the work to be carried out to the satisfaction of Lloyd’s Register
surveyors. In order that the ship maintains its class, approval of the repairs
undertaken must be obtained from the surveyors either at the time of the
repair or at the earliest opportunity.
Survey requirement
Survey on board cargo ships
Can be divided into a few major group
a) Statutory survey
b) Class survey
c) Other survey
Statutory survey:-
i) Load line survey (5 years)
ii) Safety Construction (5 years)
iii) IOPP (5 years)
iv) Safety Equipment (2 years)
v) Safety Radio Telegraphy (1 year)
Class survey:-
# Special hull survey
# Special machinery survey
# Annual survey for hull & machinery
# Intermediate survey, hull
# Bottom
# Tail shaft
# Auxiliary boiler, oil fired
# Auxiliary boiler, exhaust
Other survey
#Cargo gear survey
#Admin. survey
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