Print Reading

Locating Underground Facilities While you will have used a service to locate underground utilities before construction, drawings will also be used to understand more about the underground structures before excavation starts. Also, you will use drawings to document your construction as the project progresses and after it is finished. These are called as-built drawings and will be valuable when future work is needed in the area.

Typical Drawing Determine the approximate location of underground utilities by using maps, drawings, and records and then take measurements. Make sure to consider any construction that has happened over time that could have affected the location of valves or the gas line itself.

Items Used Read prints and diagrams and interpret survey data. Use maps and records. Determine general locations.

Underground Picture While it would be great to have a picture like this of the utilities below the surface, we have to depend on location markings and drawings to visualize the location of underground utilities and structures.

Typical Symbols

Site Plan Symbols

Additional Items Sometimes drawings will include additional markings to prove useful information. What is this drawing showing us? Multiple telephone ducts 20” wide. Single gas pipeline. 18” tolerance zone either side of the ducts. 18” tolerance zone either side of the gas pipeline. Note the display of dimension information and the notation for inches.

Explain: This is as as-built drawing. The task was to install a 4” PL gas line. Point to all items and explain their significance. Point out the starting point and how it is located by measuring from existing above-ground structures. Note the length and path of the new line along with deviations from straight line. Note the depth of the line and variations in the depth. What does 68’ west of pole #60084 mean? Where is pole #60084?

Related Page Pole #60084 is on a different page. Will need to look at several drawings and put the information together. Show common elements on the two drawings, such as dimensions, street names, and equipment, to show how to tie them together for a complete picture of the job.

Activity Identify information needed from a drawing. Present findings. Use prints and drawings available locally to complete the activity sheets. Provide sufficient sheets for the number of prints and drawings used in the activity. Have individuals share information learned from their drawings.

Summary Drawings and prints show what’s underground. Drawings and prints reveal hidden lines and structures. Drawings and prints are essential to complete and safe natural gas installations.