Identify the different types of personal safety
OBJECTIVES: Read and
interpret blueprints, drawings, diagrams, and
other maintenance aids.
As an ABE you will be required to read blueprints
and drawings during the performance of many
operational readiness of the catapults and the arresting
gear engines. As you advance in rating you may also be
required to make sketches and drawings, which will
maintenance personnel by making it possible for them
to visualize the system or object you are explaining.
BLUEPRINTS AND DRAWINGS
Blueprints are exact copies of mechanical or other
types of drawings and employ a language of their own.
It is a form of sign language or shorthand that uses
lines, graphic symbols, dimensions, and notations to
accurately describe the form size, kind of material,
finish, and construction of an object. It can be said that
blueprint reading is largely a matter of translating these
lines and symbols into terms of procedure, materials,
and other details needed to repair, maintain, or fabricate
the object described on the print.
Usually you can look at a blueprint and recognize
the object if you are familiar with the actual part. But
when you are required to make or check on a certain
part, the applicable blueprint must be referred to in
information. The important thing is to know what the
different symbols stand for and where to look for the
important information on a blueprint. Some of the
important facts listed on all blueprints are discussed in
the following paragraphs.
The title block is located in the lower right corner of
all blueprints and drawings prepared according to
military standards. The block contains the drawing
number, the name of the part or assembly that the
blueprint represents, and all information required to
identify the part or assembly.
The title block also includes the name and address
of the Government agency or organization preparing
the drawing, the scale, drafting record, authentication,
and the date (fig. 1-4).
A space within the title block with a diagonal or
slant line drawn across it indicates that the information
usually placed in it is not required or is given elsewhere
on the drawing.
The revision block (not shown) is usually located in
the upper right corner of the blueprint and is used for
the recording of changes (revisions) to the print. All
revisions are noted in this block and are dated and
identified by a letter and a brief description of the
revision. A revised drawing is shown by the addition of
a letter to the original number in the title block, as
shown in figure 1-4, view A. If the print shown in figure
1-4, view A, was again revised, the letter in the revision
block of the title block would be replaced by the
All blueprints are identified by a drawing number
(NAVSHIP Systems Command No. in view A of fig.
1-4, and FEC Drawing No. in view B), which appears in
a block in the lower right corner of the title block. It
may be shown in other places also; for example, near
the top border line in an upper corner, or on the reverse
side at both ends so that it will be visible when a
drawing is rolled up. If a blueprint has more than one
sheet, this information is included in the block
indicating the sheet number and the number of sheets in
the series. For example, note that in the title blocks
shown in figure 1-4 the blueprint is sheet 1 of 1.
Reference numbers that appear in the title block
refer to numbers of other blueprints. When more than
one detail is shown on a drawing, a dash and a number
are frequently used. For example, if two parts are
shown in one detail drawing, both prints would have the
same drawing number, plus a dash and an individual
number, such as 8117041-1 and 8117041-2.
In addition to appearing in the title block, the dash
and number may appear on the face of the drawings,
near the parts they identify. Some commercial prints
show the drawing and dash number, and point with a
leader line to the part; others use a circle, 3/8 inch in