COMPARTMENT DESIGNATION/DECK
NUMBERING SYSTEM
Learning Objectives: When you finish this chapter,
you will be able to—
Recall compartment designations.
Recall deck lettering and numbering systems.
Every space in a ship (except minor spaces, such as
pea coat lockers, linen lockers, and cleaning gear
lockers) is assigned an identifying letter and number
symbol. This symbol is marked on a label plate secured
to the door, hatch, or bulkhead of the compartment.
Compartments on the port side end in an even number
and those on the starboard side end in an odd number
(fig. 8-11). A zero precedes the deck number for all
levels above the main deck. Figure 8-12 shows the
system of numbering decks.
Ship’s compartment designations consist of a deck
number, a frame number, the relationship of the
compartment to the centerline, and a letter showing the
use of the space. Where a compartment extends through
two or more decks, the number of the lower deck is used.
The frame number indicates the foremost bulkhead of
the compartment. If the forward boundary is between
frames, the frame number farthest forward within the
compartment is used.
Compartments located on the centerline carry the
number 0. Compartments to starboard are given odd
numbers, and compartments to port are given even
numbers. Where two or more compartments have the
same deck and frame number, they have consecutively
higher odd or even numbers, as applicable, numbering
from the centerline outboard. For example, the first
compartment to starboard is 1, the second is 3, and so
on. To port of the centerline, they are numbered 2, 4, and
so on. When the centerline passes through more than
one compartment with the same frame number, the
compartment having the forward bulkhead through
which the centerline passes carries the number 0.
Compartments above the main deck are numbered 01,
02, 03, as applicable, shown in figure 8-12.
The last part of the compartment number is the
letter that identifies the primary use of the compartment.
On dry and liquid cargo ships, a double letter is used for
cargo holds to differentiate them from spaces
containing the same commodity for use by the ship (for
example, fuel oil). Compartment usage in the present
system is shown in table 8-1.
8-11
Student Notes:
Figure 8-11.—Compartment designations.
Figure 8-12.—Deck numbering system.
