So, how do the pros do this?

3-4-5 or 5-12-13 is a hint.

Why do you need to set up on it?

it depends on what the pro is trying to do.... (for one thing- I'd don't set instruments over pipes...)

I'm "re-tracing" the boundary. I've traversed to the corner; I'm turning the corner, and measuring the angle between from whence I came, to the next line...a stone fence line.

The hint about using trig to set up on another point, measure the angle from there, and extrapolate the location of the corner sounds like it might work.

I surmise that the question has to do more with using a total station, with which one could do something similar to an offset shot to a point on the next line adjacent to the pipe, but I'm not sure.

Set a point a few feet away from the pipe and side shoot the corner pipe. I seldom occupy the actual corner. Close on another point.

I saw a college class problem from 1982 that illustrated a method that was probably in common use even with transits.

Most of the corners of the land to be surveyed were in or near fence lines or trees and difficult to occupy. The surveyor set stakes with nails near those corners but where he had good visibility to the rest of the land. He took angles to everything out in the open, with short side shots to the corners. He measured all the actual property lines he could, and the distances for the side shots.

It made for a lot of number crunching on a pocket calculator to solve all the triangles, but it was straightforward.

I expect a lot of surveyors would do the same thing now, only the number crunching would be almost invisible in the data collector.

If I were doing it myself, I'd do the calculations with my home-brew least squares program. It works even with just-sufficient measurements, but I'd try to get some redundancy as a check. Email me (through the link beside my name) if you want to play with my program. It's a poor imitation of Star*Net's 2-D capability, and at the present doesn't draw the graphical output, but gets the same coordinates to 4 decimals. You can also download the real Star*Net and run "demo mode" which is only crippled by a limitation to 10 points.

99.99% of the time survey crews do not set up over the property corner monuments. We set up on "control points" or "traverse points" (nails, stake & tack, small drill hole, etc.) that has the best line of sight to whatever items we need to measure to (property monuments, house corners, driveway points, garages, out buildings, walks, water meters, etc.) and perform a random traverse. Most crews set enough to perform a closed traverse to be able to check mathematical closure and adjust if needed. You begin with a 0° angle to a backsight (usually) and also shoot a distance. Then you shoot another control point (or traverse point) with an angle and distance, then you shoot all the property corners with angles and distances and you use trig to calculate the coordinates of each point, same with house corners, etc.

Just because you have found some property monuments (maybe) does not mean that you can apply the perfect angles/bearings and distances and magically be surveying and setting corners and such.

Carl

I thought I read something about how in Texas you are virtually compelled to set up over all the monuments or it's not a true survey. That might work on the Staked Plains but it sure wouldn't work in my part of the world with hundreds of 100 year-old hedge/bois d'arc/osage orange trees directly on most major property lines.

Wouldn't work here for chain link fences, trees, hedges and 100 other reasons.

Back in the day I may not have even bothered with a triangle. Turn to it and drop a hub and tack a few feet short on line. Set on the hub and work the offset line...

What would you do if the pipe were flush with a building face. You certainly couldn't set up over the pipe. I'd set a random point and sideshoot the pipe. Perfectly proper procedure and essential in a lot of cases, like this one.

I remember one section corner in Davie, Florida where by 1968 the pipe was well inside the tree, with a side chopped off to expose it.

In 1994 found a rail end exposed inside the cavity of a hollow Sweetgum that was called as being found in a deed from 1954.

When I began surveying there were a few party chiefs that insisted upon measuring directly from monument to monument and it took alot of brush and tree cutting and some real clever estimating line by a few of them.

In the days of compass and chain, that was a common practice. Many carried the same techniques into use with the transit.

There are many methods to locate monument without occupying and continue the survey.

I believe it good to occupy monuments when permissible. The contrary is the usual case.

Still it is a suitable way to look for monuments with the least amount of calculations.

It is important to remember that retracing the survey does not mean to deed stake the missing monuments without checking adjoining property rights.

Random traverse is the most common way.

0.02

Thanks for all the input. I realize now that part of my motivation was to reduce the amount of trig, but come to think of it, it'd probably do me good to DO more trig along the way.

By the way, when I asked an old surveyor I ran into around here why there always seemed to be so many trees right on fence lines, he said it was well known that birds eat the tree seeds, sit on the fences and poop them, only to become trees 20 years later! Don't know if that's true.

Random traverses with side shots it is.

So, how do the pros do this?>Set up over Bound!

For what it's worth, the previous statement about "99.99% of the surveyors don't set up over monuments" is not correct.

I try to set up on original bounds, always, if possible. It's much stronger to have the control part of your closed traverse than as a side shot. Anyone who says differently is just plain wrong.

So, how do the pros do this?>Set up over Bound!

Random traverse for the last 40 years around here. Can't imagine anyone trying to occupy all the corners. For land surveying work the results in accuracy is good as occuping every point. Trying to get millimeter in this business is overkill.
Places in my area a few tenths is good.
And the thing Cow mentioned about Texas is total bunk.

So, how do the pros do this?>Set up over Bound!

In the late 80's I worked for a company that had a contract with a US Army Corps of Engineers district. The guy at the Corps was a stickler for following specs. The crew was setup on a traverse point, and was tying in a property corner nearby (less than 10' away). They did a quick sideshot (D+R), and kept going. When they turned in the field book, he rejected the survey and made them go back (150 miles away) because they did not turn 8 sets of angles (second order FGCS traverse spec) to that corner.

If I can't set up on it

don't call the hall. That's what my brother would say. 3' seems far enough away from the tree to me. When you can't get your head in there is when you can't do it. The gun would have to be dang near touching the tree. Keep trying, buddy. If I had the time, I'd come out there and set that gun up for you.

Also, anyone who avoids setting on corner points 99.99% of the time is doing themselves a great disservice. And never setting on pipes seems a bit exclusionary as well. Jam a nail in beside it if it makes you feel better. We've surveyed the offset line as well and measured over to hang flagging.

I agree with all of the above. Basically, you find a way to measure it in. I don't know if it may have moved when tree roots startedgrowing around it (or if the tree could have pushed it sideways. I also agree that I often consider it a challenge to try to set up over a difficult point.

If I were surveying that boundary where the pin is, (as opposed to tying it in on a neighboring property) I would consider setting a witness-corner monument or two along the line coming in to the corner and leaving the corner.

As to the bird-pooping birds, that sounds plausable. I would also consider that the trees that are growing right on the property line were purposely planted along the property line. If they were planted to help demark the boundary line, they could well be considered "boundary line trees" which could have it's own implication, including helping to decide where the original boundary line fell.

> I thought I read something about how in Texas you are virtually compelled to set up over all the monuments or it's not a true survey. That might work on the Staked Plains but it sure wouldn't work in my part of the world with hundreds of 100 year-old hedge/bois d'arc/osage orange trees directly on most major property lines.

you read wrong. we maybe occupy about 1 in 1000 boundary monuments directly, for all of the obvious reasons.