figures 3-15 to 3-21, and in NAVFACENGCOM drawing numbers issued to individual engineering field divisions are within the following limits:

NAVFACENGCOM headquarters retains custody of all of the numbers up to and including 1 999 999 and all other drawing numbers not assigned. Each cognizant EFD is responsible for the control of assigned numbers for issuing, assigning, and recording these numbers for its own use or the use of activities within its geographical area. Each activity maintains an assignment record including locations and drawing titles of drawing numbers assigned to it.

Figure 10-2.-A title block showing a drawing number assigned by NAVFACENGCOM.

(Figure 10-2 is an example of a local activity, such as the Civil Engineering Support Office (CESO), using a drawing number assigned by the Western (WESTDIV).)

Figure 10-2.A title block showing a number assigned by NAVFACENGCOM. You may not use a NAVFACENGCOM number for any other drawing, even though the drawing to which it has been assigned is not being used. Sometimes, because of extensive revision on a particular drawing, it becomes necessary to prepare a new drawing and to assign a new NAVFACENGCOM drawing number. A cross-reference note to be placed directly above or adjacent to the title block is shown below.

THIS DRAWING SUPERSEDED BY DRAWING NO._______

THIS DRAWING SUPER-SEDES DRAWING NO. _______

Drawing Revisions

Revisions to NAVFACENGCOM project drawings are to be made according to DOD-STD-100C. The revision block may include a separate "PREPARED BY" column to indicate the organization, such as an A/E firm, that prepared the revision. The layout of the modified revision block is to be as shown in chapter 3, figure 3-22, views A and B.

Graphic scales are located in the lower right-hand corner of each drawing sheet, with the words Graphic Scales directly over them. The correct graphic scales must be shown prominently on each drawing because, as drawings are reduced in size, the reductions are often NOT to scaled proportions.

You should pay close attention to the opaqueness and uniform weight of lines. To provide contrasting division and use of thick and thin lines, refer to chapter 3, figure 3-23, and ANSI Y14.2M, Line Conventions and Lettering, Engineering Drawing and Related Documentation Practices. where lowercase lettering may be used. The minimum allowable height of freehand letters is 5/32 (0.156) in., and of mechanical or computer graphics is 0.150 in. For abbreviations on drawings, use MIL-STD-12, Abbreviations.