> When looking at a plat from the last 10 years, has the way that the subdividing surveyor determined North relative to their basis of bearing ever changed where you would replace a missing corner, using existing monuments?
>
>
> This an honest question. I feel I am missing something in this basis of bearing discussion.
Not one iota.
The fact that ALL subdivisions (not admin plats) we've prepared for the last 7 or 8 years are all on grid is irrelevant. The corners on the ground dictate the tract's location, not a bearing.
> > When looking at a plat from the last 10 years, has the way that the subdividing surveyor determined North relative to their basis of bearing ever changed where you would replace a missing corner, using existing monuments?
>
> Sure, of course. Why would it not? Do you never have to deal with situations where some subset of the boundary markers are of questionable stability? Between:
>
> (a) utility and road construction,
> (b) lot grading,
> (c) foundation contractors driving 2x4's right next to a stake for a string line,
> (d) fence builders,
> (e) soil movements, and
> (f) various other events,
>
> it's a common task to to try to figure out which markers actually are original, undisturbed monuments shown on the original subdivision plat. Being able to independently reproduce the bearings of lines is a huge advantage.
But not requisite for them to be grid or astro, only reproducible. They can be mutually exclusive of one another.
rambleon
I have to tell you, I was shocked a licensed surveyor would use a tie off a plat and ignore the rest of the evidence which was literally towering over them. In hindsight, I believe he may have been trying to make the problem worse in order to create a problem for us with our client.
Occupy A Monument And Turning A Record Angle...
..is not looking at the whole.
I said nothing about needing a bearing system to do that.
Paul in PA
> > One minor question: Am I right in thinking that you actually aren't a surveyor, but are employed by one?
> That's more than a little impertinent.
Not really if you consider "surveyor" to be a protected term like "doctor" and "engineer". I thought I'd understood from the poster previously that he was an unlicensed party chief, so to present himself as a "surveyor" is improper unless there are no licensing laws in his state.
> > it's a common task to to try to figure out which markers actually are original, undisturbed monuments shown on the original subdivision plat. Being able to independently reproduce the bearings of lines is a huge advantage.
>
> But not requisite for them to be grid or astro, only reproducible. They can be mutually exclusive of one another.
By "independently" one means without reference to monuments. That is, the bearing may be determined without knowing the bearing of any pair of boundary monuments as reported by some prior survey. So, an independently reproducible bearing is necessarily one that refers to grid North of some known projection or to geodetic (or astronomic) North.
No.
Basis of bearings IS nice for the GIS folks for mapping. 80 percent of what I do is on the Wisconsin County Coordinate System. Makes the mapping technicians feel warm and fuzzy when they don't have to rotate.
No.
I would never grab a plan, and think that I can occupy a monument, and then run a bearing to monument the line or corner, solely because I'm on the same SPCS as the record plan.
That would be unprofessional and insane.
rambleon
> I believe he may have been trying to make the problem worse in order to create a problem for us with our client.
If that was the case he should definitely not be licensed anymore. Completely unprofessional.
FYI-
License Information:
Name: MYHILL, DAVID HOWARD
License Type: Professional Land Surveyor
License Number: 49284
License Status: Active
First Issued Date: May 10 2012
License Issued: Oct 31 2012
Expiration Date: Nov 2 2014
> License Information:
>
>
> Name: MYHILL, DAVID HOWARD
> License Type: Professional Land Surveyor
> License Number: 49284
> License Status: Active
> First Issued Date: May 10 2012
> License Issued: Oct 31 2012
Okay, I missed the news that the poster had actually recently obtained a license. That casts his request: "If that makes me a poor surveyor, I want to know it. Please correct me." in another light entirely. It's entirely appropriate for a professional surveyor to want to eschew poor practices as the poster evidently seeks to do.
> I think in many areas municipalities have made the decision and require certain precision and bearing basis for new subdivision. [...] But this would theoretically also allow quick replacement of disturbed or missing monuments, or addition of new ones on line without the expense of scouring the entire subdivision for evidence in order to piece it together.
Exactly, Duane. Anyone with any experience at all will recognize that that subset of remaining original monuments dwindles over time, making the boundary retracement problem progressively more difficult to the point of becoming somewhat arbitrary when those same monuments are absolutely required to reconstruct the North direction to which the bearings noted on the plat you're following refer. Being able at all times to reproduce the bearing basis is a gigantic advantage. So is not having to admit that you actually have no idea which way North is and that the bearings you showed on your map were merely based upon the supposition that old so-and-so knew which way North was when it can be shown that old so-and-so did not, thus avoiding being made to look like something much less than a diligent surveyor.
This scares me.
> > But this would theoretically also allow quick replacement of disturbed or missing monuments, or addition of new ones on line without the expense of scouring the entire subdivision for evidence in order to piece it together.
>
> .
Too expensive and time consuming to find the monuments??? Replacing pins and running lines without proper recon? this is exactly what scares me about requiring georeferenced bearings. People will use it to take shortcuts.
If your worried about it, put more ties on the plat to other monuments and physical objects. Surveyors that line on the tree-less plains need to see what we are up against working in the dark woods in colonial lands.
This scares me.
I know. What ever happened to penalty of death for use of a compass? Maps and deeds instead of beating the bounds? All this new technology and knowledge has thrown boundaries into chaos these past several hundred years.
It is scary, but the game of drones is on. Win or die.
Not actually setting missing monuments, but finding and accepting the actual original monuments versus the very visibly marked and 'official' looking replacements.
Bearings - Yes.
Coordinates Systems - Yes.
There are several sections around Barkley Lake in Kentucky that were re-monumented by some company contracted by the COE. In many places, there are duplicate monuments because the contracted company did a poor job (sometimes as much as 20 feet away from the original). I have used both published COE SPCS positions combined with the grid bearings to find that the pins with the COE posts beside of them were actually not where the original corner was.
And those original COE surveys are from the 1960s.
This scares me.
> Too expensive and time consuming to find the monuments??? Replacing pins and running lines without proper recon?
I guess the disadvantage of working in rural New Hampshire is that you can't imagine how hard modern life in an urban or urbanizing area is on survey monuments. It's fun to imagine that if one were to just dig deep enough, all of the original monuments would suddenly appear, and undisturbed, too, but the reality is otherwise. The reality is that road construction puts the Caterpillar touch on markers, bending and shifting them. Utility construction destroys them. Fence builders preserve them by removing them and then putting them "right back where they were". More insidiously, quickie-dickie residential surveyors add new markers in novel and idiotic positions that often conceal the originals.
It should be obvious that reestablishing the bearing basis of a subdivision plat by solving the rotation parameter of the coordinate system from the actual positions of some number of survey markers is both less accurate and more time consuming than knowing what the bearing basis is to begin with and being able to reproduce it without raising a sweat.