Pipe Crossings Plan View...

[Jerry_Barnes]

I can get elevations from crossing pipe profiles to appear in a plan view label, resulting in a label shown in the attached screen shot. 

My question is: Is it possible to create an expression that would calculate the difference between the two elevations (i.e. the clearance between the two crossing pipes) that could be used in a plan view label?

[BrianHailey]

I don't think it can be done out of the box. Expressions only look at one object, not multiple objects. You would need to create a custom program.

Perhaps @Jeff_M has something like this in SincPac.

[Joe-Bouza]

Nice label. Would you be willing to share it?

[Jerry_Barnes]

Joe - The attached drawing file has an alignment Station Offset label called "Utility Crossing" to see how I laid it out. Here are some additional comments: (Note that this label works only in PLAN view.)

1. Both crossing pipe runs need to be profiled in profile view.
2. Pipe runs in profile view need to have profiles created that follow the top and/or bottom of the pipe as needed; probably outside of pipe is best.
3. The alignments and the pipe profiles need to be data shortcuts if used in outside files, and referenced into those files.
4. The Station Offset label includes two Profile Reference Text parameters: one for the Upper Pipe Profile, and one for the Lower Pipe Profile. 
5. Each reference text has the property "Profile Elevation" included (you can add "Alignment Name" and "Station Value" if desired).
6. When applying the label, click on one of the crossing alignments, select the crossing point, and it will prompt you for the Upper Pipe Profile from which to grab the elevation at that point. Then it will prompt for the Lower Pipe Profile to grab its elevation at that point. (Note: revisions in pipe elevations will dynamically update the label only if the profiles are updated as well.)

The main caveat is that if one or both of the pipe runs change horizontally, the label will not dynamically track the crossing point and may be pointing at a meaningless spot. And, if the runs switch order vertically in a later revision, the label will be incorrectly indicating which is the lower and which is the upper pipe.

[Joe-Bouza]

Thank you castled71049, thats nice of you.