Page 35 - Ship Construction.DJ Eyres 6Ed

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24 Ship Construction
received considerable attention in the work of IMO, the classification soci-
eties and elsewhere. Based on experience of failures of lesser consequence
it was concluded that the casualties occurred through local structural fail-
ure leading to loss of watertight integrity of the side shell followed by pro-
gressive flooding through damaged bulkheads. The flooding resulting
either in excessive hull bending stresses or excessive trim, and loss of the
ship. Much of this work concentrated on the structural hull details, stresses
--- ใช้เพื่อการศึกษาเท่านั้น---
experienced as the result of loading and discharging cargoes (past experi-
ence showed that ships were often loaded in patterns not approved in the
ships loading manual), damage to structure and protective coatings arising
งานห้องสมุด ศูนย์ฝกพาณิชย์นาวี
from discharging cargoes, poor maintenance and subsequent inadequate
inspection of the ship structure. The initial outcome of this work was the
introduction of a new Chapter XII of SOLAS covering damage stability
requirements, structural strength requirements and enhanced survey proce-
th
dures for bulk carriers. At its 79 session in December 2004 the Maritime
Safety Committee of IMO adopted a new text of Chapter XII of SOLAS
that included restrictions on sailing with any hold empty and requirements
for double-skin construction as an optional alternative to single side-skin
construction. The option of double side-skin construction applies only to
new bulk carriers of 150 metres or more in length, carrying solid bulk car-
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3
goes having a density of 1000 kg/m and above. These amendments entered
into force on 1 July 2006. The midship section of a Handysize bulk carrier
with double-skin construction is shown in Figure 17.8.

Car Carriers

The increasing volume of car and truck production in the East (Japan,
Korea and China) and a large customer base in the West has seen the intro-
duction and rapid increase in number of ships specifically designed and
built to facilitate the delivery of these vehicles globally.
Probably the ugliest ships afloat, car carriers are strictly functional having
a very high boxlike form above the waterline to accommodate as many vehicles
as possible on, in some cases as many as a dozen decks. Whilst most deck
spacing is to suit cars some tween deck heights may be greater and the deck
strengthened to permit loading of higher and heavier vehicles. Within such
greater deck spacing liftable car decks may be fitted for flexibility of
stowage. The spacing of fixed car decks can vary from 1.85 to 2.3 metres to
accommodate varying shape and height of cars. Transfer arrangements for
vehicles from the main deck are by means of hoistable ramps which can be
lifted and lowered whilst bearing the vehicles. Loading and discharging
vehicles onto and off the ship is via a large quarter ramp at the stern and a
side shell or stern ramp. The crew accommodation and forward wheelhouse,
providing an adequate view forward, sit atop the uppermost continuous