Tip #15 - Using Best-Fit Line to Draft Catenary Lines
Did you know you can use the Best-Fit Line to draft catenary power lines in TBC? This accurate and time-saving tool creates a 3D linestring that can then be used to compute and document minimum clearances, in a Plan Set, or exported in a third-party data format.
Here’s a typical situation:
Station View in TBC - Panorama and Point Cloud data
Powerline and tower data has been collected by a Trimble VISION instrument. Included in the data are points along the powerline, either through scans and/or Direct Reflex (DR) topo in the field, or Virtual DR in TBC.
In this example, the powerline data is a part of some SX10 station setup scans. After refinement with the Classify Regions and Keep In/Keep Out commands to extract the power lines you wish to draft, view the powerlines in 3D View:
![](https://higherlogicdownload.s3.amazonaws.com/TRIMBLE/JiveInlineImages/134533.png)
Point Cloud only view in 3D
![](https://higherlogicdownload.s3.amazonaws.com/TRIMBLE/JiveInlineImages/134534.png)
Point Cloud Data after Region Classification, Turning Regions off in View Filter, and using Keep Out to Remove Points
Using the Polygon Select tool, create a selection polygon around one powerline at a time to select each point on the powerline. Open the Best-Fit Line command in the CAD tab (licensed by the Advanced Drafting module) and match these settings:
![](https://higherlogicdownload.s3.amazonaws.com/TRIMBLE/JiveInlineImages/134535.png)
Best-fit Line Command and settings
Click OK and repeat for the other two power lines.
![](https://higherlogicdownload.s3.amazonaws.com/TRIMBLE/JiveInlineImages/134536.png)
Finished 3D Linestrings
Once completed, you’ll have three 3D linestrings for use in your TBC deliverable!
![](https://higherlogicdownload.s3.amazonaws.com/TRIMBLE/JiveInlineImages/134537.png)
Station View with Power Lines Drafted
Special thanks to Chad Lewis for the data set and workflow suggestion this week!