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BLM 2009 Manual, sec. 7-23
Posted by Keith on July 22, 2010 at 9:31 pmJunior-Senior Corners
7-23. This situation exists where one set of corners was established for one side of the line, and a second set of corners was established for the other side of the of the same line in the course of a later resurvey or retracement (figure 7-4).
The line is regarded as having been fixed in position by the senior survey and subsequent dependent resurveys or retracements. If both sets of corners are recovered, a junior survey,if it was established in the course of an obvious careful resurvey or retracement, reporting the most recent measurement of the line, will be used for alinement of the line and for control in restoring a lost senior corner of the line.
End of quote.
Any comments on junior corners controlling senior lines?
Keith
Richard Schaut replied 14 years, 1 month ago 13 Members · 36 Replies -
36 Replies
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I don’t think that number is on a TX juke box from listening not only to Kent but other Tx surveyors, so they don’t do the 2-step to it.
or
to put it another way.
😉
When in Texas do as Texans do. -
This gives new meaning to the term “Senior Monument”,and not in a good way either.
What were they smokin?
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> Any comments on junior corners controlling senior lines?
A junior corner set during the course of a competent survey is a witness to the location of the senior line. Using it to restore the location of the senior line seems like a slam dunk to me.
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BLM 2009 Manual ?
Surveying ‘out of a book’ is one reason that Engineers make sh|tty surveyors. But, more to the point: If you plan on doing Professional surveying by using a 2009 Manual on 1840s original survey lands, you are headed for a very hard landing – like a wheel’s up landing.
Sorry, Keith, but surveying is not done with a Manual in one hand.
WB
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It is nothing new, and it makes perfect sense if you closely read what it is saying. There are many cases where there are truly no Senior/Junior corners. For example, here in Alaska, where we are still doing 90% original surveys, we run the Standard Parallel setting CC and SC as we go down the line. GPS, AutoSurveyor before that, ABC Control before that…. So those corners, although marked CC or SC, truly were set with the same quality and significance in marking the parallel. Now you go into resurvey mode, say one SC is gone, and a CC is 8 chains away. Are you going to ignore the nearby CC just because of the marking on the cap and notation on the plat it is a CC. No…. It is the best evidence of the location of the Standard Parallel. Use it and the next corner on the other side of the missing corner, whether it is a SC or CC.
What 7-23 (2009) is saying is, do not ignore good evidence just because of its notation as a CC making it historically a junior corner. Evaluate the survey that set the CC, see if it faithfully retraced the Senior line (such as the survey that set the CC ran the senior line and made note that it set the CC exactly at the junior/senior intersection), or in the case of my example, see if it truly was set as a CC or rather as a monument with equal standing for control, and make your decision.
I disagree @WB that the BLM Manual is a textbook like an engineering book that has one answer, or that the Federal Surveyor uses it alone to direct a survey decision. If you think it is, you have not read it, or understood it. And yes @WB the 2009 Manual is relevant to resurveys of older surveys done under prior Manuals, it is the latest official guidance to the Federal Surveyor, and as such is a integral document to use, and the Special Instructions for the Survey dictate that the current day survey be done in accordance with it. The prior Manuals are used to for the understanding of the guidance given to the Federal Cadastral Surveyors when they were doing their surveys. The BLM Manuals, including the 2009 edition, are guidance to the Federal Surveyor to lead him to the crossroads of the question at hand of how to properly evaluate the evidence, and make the correct decision to place the line being resurveyed in its original location. And in the end, the BLM Cadastral Chief who holds the Delegation from the Secretary of Interior, makes the decision that resurvey has correctly re-established the line, when he/she approves the notes and plat.
I may not have much time for rebuttal tomorrow if there is any, I am meetings in the morning, then headed out off of the grid until Monday.
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> Any comments on junior corners controlling senior lines?
Well, in your example, it sounds as if the monuments established after the original controlling monuments are important only to the extent that they can be shown to perpetuate the positions of the originals. They do not “control” the line in the sense that most surveyors I know would use the term.
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The way this was presented to us was that the present day surveyor is able to use the somewhat subjective judgement as to when to accept a junior corner such as a CC as being the correct position instead of pin cushioning the position because the junior corner was “off” by 0.4′.
I can agree that is a reasonable use of professional judgement.And what Jim said above. Well stated Jim.
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Kent
You are not reading and understanding the section and obviously don’t want to. The section clearly is referring to the senior line as originally established by the senior corners. It goes on to state that; “The line is regarded as having been fixed in position by the senior survey and subsequent dependent resurveys or retracements.
It can’t be any clearer!
Keith
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clearcut
The quoted section is not about the position of the CC and how close it is to the line, as you stated.
Keith
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Kent
> It goes on to state that; “The line is regarded as having been fixed in position by the senior survey and subsequent dependent resurveys or retracements.
Well a certain fellow you know has coninually opined that the lines of the senior survey are not fixed, but are “bent” by as many survey monuments as were subsequently placed along the line. Just so you know.
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Keith
Correct me if I have this wrong but the BLM has always held monuments set AFTER the original if they were set attempting to use the manual methods. They do not have a problem with measurements that are slightly in error as long as the rules were followed.
The ones they often do not accept are the ones that were not set using the manual methods.
My understanding is that they do not worry about the absolute position but more in the correct methodology.
Deral
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Kent
You only see what you want to see!
Try to understand the plain English in junior corners bending the senior line.
Try blinking and read it again.
Keith
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Kent
> Try to understand the plain English in junior corners bending the senior line.
Hey, it sounds as if your argument is with the BLM if you don’t want to consider original survey lines as being fixed in a definite position. :>
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Kent
What does this mean to you; “. . .and subsequent dependent resurveys or retracements.”?
You simply don’t want to understand it.
Keith
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Deral
You are right and it only makes sense to use “subsequent monumentation” for controlling boundaries.
If one thinks about it for a minute and a half, one will understand that probably 90 percent of corner monuments being set are “junior” and should one think that they do not control boundaries?
How many of you are setting “original corner monuments”?
This is land surveying 101.
Keith
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Kent
I could understand an argument of yours that simply said the Manual does not control boundaries in Texas (which it does not) and the argument that it is not done that way in my parts, but to make your arguments that clearly show you don’t want to understand the Manual, is just silly.
Land surveying is not about finding only the original corner monuments and then run an instrument straight line between them and ignore all other evidence of the boundary.
I can’t believe that is true, even in Texas.
Keith
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When the location of established monumentation met the applicable standard of accuracy at the time they were placed and the land owners have relied on the location, those monuments are fixed and control the location of the intended lines.
If it is determined that specific monument positioning did not meet the accuracy standard a the time it was set, but owners have relied on that monument, it is necessary to correct the record in order to preserve the position of the legal property line.
Therefore, minor deviations in direction between established monuments are normal. Just as a section line will bend at the 1/4 corner, any described line will include undefined angle points that are set as part of subsequent parcel creations.
The above principle applies all over the US because the rights of landowners are the same all over the US. Once a territory became a state, the rights of the citizens of that territory became the rights of US citizens.
Richard Schaut
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I have never read of “accuracy standards” for the acceptance of existing monuments?
Please post.
Keith
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