MICROFILM/APERTURE CARDS
Many prints and drawings are procured in the form
of 16- and 35-mm microfilm. Microfilm prints and
drawings are available mounted on aperture (viewer)
cards, as well as in roll form. A reader or some type of
projector is required to enlarge the microfilm for
reading. Activities are provided with a microfilm
reader-printer, which as its name implies, enlarges the
microfilm for reading and also has the capability of
printing a working copy in a matter of a few seconds.
Microfilm greatly reduces the size of otherwise
bulky files, which is very important aboard ship.
SCHEMATIC DIAGRAMS
Schematic diagrams show by means of single lines
and symbols how the parts of a system are connected
for the operation of the system.
Piping
Piping diagrams are normally used to trace piping
systems and their functions without actually describing
the shape, size, or location of the components or parts.
Each component is represented by a symbol; and once
these symbols are learned, the piping schematic
diagram is easy to read.
Figure 1-7 is a good example of a piping diagram.
As may be seen from this example, diagrams do not
indicate the location of individual components within
the station, but do locate the components with respect
to each other within the system.
Electrical
Schematic diagrams are also used to depict
electrical systems. They are basically the same as the
1-8
PHANTOM LINE
CENTER LINE
DIMENSION LINE
OUTLINE
HIDDEN LINE
CUTTING PLANE LINE
BREAK LINE
EXTENSION LINE
LEADER LINE
SECTIONING LINE
SECTION - AA
ABEf0175
A
A
Figure 1-6.—Use of standard lines.
COOLING PANEL
ABEf0176
8
9
7
10
P
M.C.
CATAPULT
CONSOLE
11
12
6
5
P
3
4
2
13
1
FIREMAIN
OVERBOARD
Cutout valve.
Reducing valve
Throttling valve.
Relief valve.
Test gauge.
1.
2.
3.
4.
5.
Hytrol valve.
Pilot valve.
Inlet lines.
Discharge lines.
Pressure gage.
6.
7.
8.
9.
10.
Orifice.
Scupper
valve.
Hose
valves.
11.
12.
13.
Figure 1-7.—Typical piping schematic for saltwater cooling.
