Sectional Views

(Builder) to illustrate some portion of the work. As a Builder, you will have to make shop drawings for minor shop and field projects. These may include shop items—such as doors, cabinets, and small portable buildings, prefabricated berthing quarters, and modifications of existing structures. Shop drawings are prepared from portions of design drawings, or from freehand sketches based on the Builder’s past building experience. They must include enough information for the crew to complete the job. Normally, the Builder bases the amount of required detailing on the experience level of the crew expected to complete the project. When an experienced building crew will be doing the work, it is not necessary to show all the fine standard details. When you make actual drawings, templates (when available) should be used for standard symbols. Standard technical drawing techniques are recommended but not mandatory. For techniques in the skill of drawing, refer to Blueprint Reading and Sketching, NAVEDTRA 10077. FREEHAND SKETCHES Builders must be able to read and work from drawings and specifications and make quick, accurate sketches when conveying technical information or ideas. Sketches that you will prepare may be for your own use or for use by other crewmembers. One of the main advantages of sketching is that few materials are required. Basically, pencil and paper are all you need. The type of sketch prepared and personal preference determine the materials used. Most of your sketches will be done on some type of scratch paper. The advantage of sketching on tracing paper is the ease with which sketches can be modified or-redeveloped simply by placing transparent paper over previous sketches or existing drawings. Cross-sectional or graph paper may be used to save time when you need to draw sketches to scale. For making dimensional sketches in the field, you will need a measuring tape or pocket rule, depending on the extent of the measurements taken. In freehand pencil sketching, draw each line with a series of short strokes instead of with one stroke. Strive for a free and easy movement of your wrist and fingers. You don’t need to be a draftsman or an artist to prepare good working sketches. Freehand sketches are prepared by the crew leader responsible for the job. Any information that will make the project more understandable may be included, although sketches needn’t be prepared in great detail. SECTIONAL VIEWS LEARNING OBJECTIVE: Upon completing this section, you should be able to interpret sectional views. Sectional views, or sections, provide important information about the height, materials, fastening and support systems, and concealed features of a structure. Figure 2-15 shows the initial development of a section and how a structure looks when cut vertically by a cutting plane. The cutting plane is not necessarily continuous, but, as with the horizontal cutting plane in building plans, may be staggered to include as much construction information as possible. Like elevations, sectional views are vertical projections. They are also detail drawings drawn to large scale. This aids in reading, and provides Figure 2-15.—Development of a sectional view. 2-14