DISPLAY CHARTS are organized primarily to convey data to nontechnical audiences. The message presents a general picture of a situation, usually comparative. There are many varieties of display charts, including bar charts, status charts, and training aids. In a SEABEE battalion, display charts are frequently used in operations and training departments. When so used, they must conform to minimum standards prescribed by the command.

Any construction job involves quantities of people, materials, and equipment. Efficient operation and completion of the job result from planning, organization, and supervision. Graphic presentation of data is important. Statistics based on the results of past jobs with similar working conditions provide a basis for predicting the amount of time that a proposed job will take. These statistics offer the best possibilities for study when presented graphically, usually in the form of a curve. The prediction of expected achievement usually is presented as a bar chart and is called a time-and-work schedule, When the scheduled work progress is compared with the actual progress (work in place), the chart is called a progress chart.

As stated earlier, there are definite guidelines in drafting. These guidelines provide uniform interpretation of all engineering drawings. Any drawing prepared by or for the Navy must be prepared following the latest military standard (MIL-STD), Department of Defense Standard (DOD-STD), and applicable NAVFACENGCOM design manuals. For subjects not covered by these References, you might refer to civilian publications, such as the Architectural Graphic Standards. Or, you may devise your own symbols, provided that any nonstandard features in your drawing are supported with adequate explanation by notes or by legend.

Many drawings continue in use for years. Therefore, you will have occasion to work with drawings that contain obsolete symbols. Look for a legend on the drawings; it should help you in reading symbols with which you are not familiar. If there is no legend, study the drawing carefully and you should be able to interpret the meaning of unfamiliar symbols and abbreviations. DoD drawing standards, which are constantly being updated, are published by the Assistant Secretary of Defense (Supply and Logistics), Office of Standardization. Any Navy activity can obtain copies of these standards by writing to the following: Naval Publications and Forms Center, 5801 Tabor Avenue, Philadelphia, PA 19120. All requests should state the title and identifying number and should be submitted on DD Form 1425. To ensure that you have the latest edition of a standard, check the Department of Defense Index of Specifications and Standards, which is issued 31 July of each year. Also check the supplements to the Index.

Current editions of the following military standards should be available to the EA:

DOD-STD-100C Engineering Drawing Prac-tices In addition, the following civilian industry standards should be on hand in the drafting room:

ANSI Y14.1 Drawing Sheet Size and Format

ANSI Y14.2 Line Conventions and Lettering

AWS A3.0-85 Welding Terms and Defi-nitions Standards