Page 50 - Ship Construction.DJ Eyres 6Ed

Ch04-H8070.fm Page 39 Wednesday, October 18, 2006 6:52 AM
Classification Societies 39
scantlings, structural arrangements and details of ship structures. This was
a response to a perception that the traditional semi-empirical published
classification rules based on experience could be inadequate for new and
larger vessel trends. The computer programs made available to shipyards
incorporate a realistic representation of the dynamic loads likely to be
experienced by the ship and are used to determine the scantlings and inves-
tigate the structural responses of critical areas of the ship’s structure.
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Lloyds Register “Ship Right Procedures for the Design, Construction
and Lifetime Care of Ships’ incorporates programs for structural design
assessment (SDA) and fatigue design assessment (FDA). Also incorpo-
rated are Construction Monitoring (CM) procedures which ensure that the
identified critical locations on the ship are built to acceptable standards and
approved construction procedures. (These provisions are mandatory for
classification of tankers of more than 190 metres in length and for other
ships where the type, size and structural configuration demand).

Periodical Surveys

To maintain the assigned class the vessel has to be examined by the Society
surveyors at regular periods. ึ
The major hull items to be examined at these surveys only are indicated
below. งานห้องสมุด ศูนย์ฝกพาณิชย์นาวี

ANNUAL SURVEYS All steel ships are required to be surveyed at intervals
of approximately one year. 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. 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 operatings systems of
tankers, chemical carriers and liquefied gas carriers.

DOCKING SURVEYS Ships are to be examined in dry dock at intervals
not exceeding 2½ years. At the drydocking survey particular attention is