Assumed Bearings

Yes, it's another survey-related blog today so if you're looking for an update in what's going on in my life, you can skip this one!

We just finished a boundary survey project here in the office. In all the deeds except for one, the same bearing system was used. The descriptions appear to have been used for quite some time, so the basis of the bearing system could not be determined but the deeds were tied into two section lines so they were easily established.

Anyway, the other description appeared to be written by a large firm here in Indianapolis. The first call from the point of commencement was described as "South 87 degrees 11 minutes 35 seconds West (assumed bearing)". Since we had used GPS to establish the location of the section corners and lines, I checked to see what our bearing was on that line. Guess what? It matched exactly to the "assumed" bearing!

I had kind of wondered why, if someone was assuming a bearing, they'd assume South 87 degrees 11 minutes 35 seconds West. Normally, we're not that good at guessing directions in the field so we probably would have assumed due west.

I guess the point of my post today is this: NOT EVERY BEARING BASE IS ASSUMED! If you established the bearings based on published coordinates, say so. If you established the bearings based on record descriptions from adjoiners' deeds, say so. If you established the bearings based on GPS observations, say so. It certainly makes it much easier to retrace your steps if we know what was used to establish your survey.