Page 305 - Ship Construction.DJ Eyres 6Ed

Ch25-H8070.fm Page 294 Wednesday, October 18, 2006 7:00 AM
294 Ship Construction

Side Deck
door hatch

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งานห้องสมุด ศูนย์ฝกพาณิชย์นาวี

Loading
platform

(a) SIDE DOOR/HATCH COVER (b) SIDE PORT CONVEYOR SYSTEM
ึ
FIGURE 25.4

when the door is opened. Combined side door/hatch covers are fitted in
designs where the ship is low in the water relative to the height of quay in
order to provide sufficient head room for forklift truck operation (see Figure
25.4). With the side port elevator system referred to above a combined
door/hatch is fitted to the hatch carrying part of the tower which houses the
upper part of the cargo elevator.
A side loader that dispenses with the need for a side door is the MacGregor-
Navire International AB’s ‘Rotoloader’. This can be a fixed or portable
installation. The unit load is raised from the quay to a point above the ships
side, swung inboard through 180° on a rotating frame unit and lowered
through the hatch to the hold or tween.

Portable Decks

Portable decks are fitted in a variety of ships permitting flexibility of stow-
age arrangements and allowing totally different cargoes to be carried on
different voyages. An extreme example is a 50 000 tonne deadweight bulk
carrier fitted with hoistable car decks stowed under the hold wing tanks
when taking ore from Australia to Japan and lowered for the return voyage
when 3000 cars are carried. The car deck is the most common form of