Superstructure deck. The superstructure deck is a partial
deck above the main, upper, or forecastle deck that
might not extend to the sides of the ship; or if it does,
it does not have side plating carried up to it.
Upper deck. The upper deck is a partial deck extending
from side to side above the main deck amidships. It is
part of the superstructure, which is the part of a ship’s
structure above the deck. The superstructure does not
include masts, yards, stacks, and related parts. The
side plating extends upward to the upper deck.
Well deck. The well deck is the forward part of the main
deck between upper deck and forecastle and aft
between the upper deck and the poop deck.
Doors and Hatches
Access through bulkheads is provided by doors and
through decks by hatches. Watertight (WT) doors, as the
term implies, form a watertight seal when properly
closed. All doors leading to weather decks are of the
watertight variety, as are those in structural (watertight)
bulkheads. (See fig. 8-4.) The doors are held closed by
fittings called dogs, which bear up tight on wedges. A
rubber gasket around the edge of the door presses
against a knife-edge around the doorframe forming a
watertight seal when all dogs are properly seated
(dogged down). Some doors have individually operated
dogs, as shown in figure 8-5. Other doors are quick
acting types, for which a handwheel or lever operates all
the dogs at once, as shown in figure 8-6. Some WT
doors have openings, called passing scuttles, through
which ammunition is passed. These scuttles (small
tubelike openings) are flashproof as well as watertight.
Nonwatertight (NWT) doors are used in NWT
bulkheads and are of various types. Some slide, some
fold, and others are similar to the regular house door
(but made of metal). Some NWT doors have dogs, but
fewer than those used on WT doors.
8-5
Student Notes:
Figure 8-4.—Dogs and gasket for watertight door.
Figure 8-5.—Watertight door with individually operated
dogs.
Figure 8-6.—Quick-acting watertight door.
