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BilboB

Question On Submitting Destroyed Marks

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My parents live outside of Boston and on a recent trip home, I was going to go into downtown Boston and hunt for some benchmarks. I thought the age of the city would harbor some particularly old marks. What I found was mark after mark listed (mostly church spires, domes, towers, and some older ones by the waterfront) that have been gone/destroyed for decades in most cases. The datasheets sometimes even state the mark was destroyed but it is still listed. Any reason why?

 

What is the proper way to clean up the datasheets? I dont feel like going around taking photos of the current areas, and digging up historical photos showing proof that the mark does not exist, but I do not have a problem going through the datasheets and providing the ones that are gone. Is that good enough, or is something more expected of me?

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Good question! Proving a negative is much harder than proving a positive. I've been doing a lot of benchmarking in nort Hudson County, New Jersey. It's quite obvious that many of the benchmarks set, and last observed, in 1932 are long gone. The most obvious is KV4066, set in 1952. I'm pretty sure that the 810' tv mast is gone. I think I could spot one of those!

Almost as obvious is KV4013. I haven't been to the actual coordinates, but a 150' grain elevator would be very hard to miss.

Somewhat less easy to prove is KV4077. The old stairs might just be buried under 30 or 40 feet of concrete. The location is definitely under the 'new' construction of the Galaxy Apartments. (The Galaxy has been there at lest twenty years.)

Many others yet to be sought.

Again, how much evidence is necessary to prove the existance of KV4074? Will they accept this photo as proof of the existance of the East Tower of Saint Mary's Chruch? This one is easy: KV4074. No one has observed it since 1936?

But, what of this? KU3997. Right location. Is it the right Memorial Church tower? It's at the right location.

Sorry. I seem to be blathering. <_<

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You are right; it is hard. Note that as most of these are third-order horizontal and of dubious pedigree, they are seldom used by surveyors. They do make interesting historical records, however, and some folks may read "hard" as "challenging" -- tackle these if you have knocked off all the brass disks in the area (search for '_MARKER: D' on the datasheets to find disks.)

 

These were, at the time of the survey, conspicuous landmarks which made easy "ready made" targets; adding them to the survey provided an additional point of measurement to strengthen the triangulation network. If near shore, they may have also been used to navigate our hydrographic survey vessels and still control the position of charted hazards (new hydro surveys use GPS). They may still be handy for land surveyors to establish an azimuth.

 

Time marches on, however, and architects certainly don't consult NGS archives when remodeling a building. As the point is usually not directly accessible, it's more of a challenge for a 'cacher to stand atop and see the "distance=0" on the handheld. For recovery purposes, you have to answer two questions:

 

1) is the landmark I'm looking at the same (or in the same horizontal location) as it was when it was originally occupied?

2) is the NGS position reasonable?

 

The facility manager may be able to describe the age of the landmark. To judge the position, you may be able to establish intersecting lines of position by navigating towards the NGS coordinate from 2 directions (90 degrees apart is best.) Your recovery note should explain to what extent or certainty you obtained the above information, your photo could be a from-the-street "tourist" shot.

 

Extra credit if you can climb all the way to the top! :D

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Note also, we still want folks to access all our data, so we don't delete a station just because the mark is "NOT FOUND". Surveyors usually "clean their own databases" by filtering these stations out before searching. THAT's why it's important not to call a mark "NOT FOUND" just because you spent just a couple of minutes kicking around for it or couldn't find a way inside the fence.

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My understanding is that it is easier to get intersection points (those towers, spires, tanks, chimneys, etc) listed as destroyed than markers. I culled out a group of markers in Missouri that had refereneces in their description to being destroyed. I sent them off to Deb Brown without any further documentation. She accepted some of them and gave me this guideline:

 

"In the future, if you come across any text that says the station is actually destroyed (not just "will be" or "possibly") and the reporting agency is NGS or a state related then those would be the ones to let me know about."

 

Sometimes we find stations that actually mentioned that they were destroyed but are still listed as not found. This helps us determine when we can easily have them officially changed to destroyed.

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We were once told to submit reports to Cheryl instead of Deb but some people still refer to sending to Deb. Could we get a re-iteration of which person deals with which kinds of submissions?

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Good question! Proving a negative is much harder than proving a positive. I've been doing a lot of benchmarking in nort Hudson County, New Jersey. It's quite obvious that many of the benchmarks set, and last observed, in 1932 are long gone. The most obvious is KV4066, set in 1952. I'm pretty sure that the 810' tv mast is gone. I think I could spot one of those!

Almost as obvious is KV4013. I haven't been to the actual coordinates, but a 150' grain elevator would be very hard to miss.

Somewhat less easy to prove is KV4077. The old stairs might just be buried under 30 or 40 feet of concrete. The location is definitely under the 'new' construction of the Galaxy Apartments. (The Galaxy has been there at lest twenty years.)

Many others yet to be sought.

Again, how much evidence is necessary to prove the existance of KV4074? Will they accept this photo as proof of the existance of the East Tower of Saint Mary's Chruch? This one is easy: KV4074. No one has observed it since 1936?

But, what of this? KU3997. Right location. Is it the right Memorial Church tower? It's at the right location.

Sorry. I seem to be blathering. :lostsignal:

Here is a history of the WOR TV tower, complete with a picture

 

http://hawkins.pair.com/wor-tv-NBergenNJ.html

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We were once told to submit reports to Cheryl instead of Deb but some people still refer to sending to Deb.  Could we get a re-iteration of which person deals with which kinds of submissions?

Deb should get all info regarding mark updates, and destroyed marks. Cheryl should be getting info on errors in the databse. That is my understanding.

 

-Casey-

Edited by caseyb

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Is there a good place to look for historical records of where marks existed? For example, the first mark that I went to look for is obviously gone, as the new bridge was created in 2002 (KA0131). This seems like one that would require a previous photo to establish a Destroyed status.

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Um, it takes a bit of doing. For example, UW7900, ANCHORAGE APT CONTROL TWR. It took some searching to find a picture of its destruction (second picture down) in the Alaskan 1964 magnitude 9.2 earthquake, probably one of the few benchmark destructions in the US involving loss of life, another being KV4448, WORLD TRADE CENTER ANTENNA.

 

Some are easy, some are hard.

Edited by BuckBrooke

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Out of curiosity, should I expect a response when I submit a destroyed mark to Deb, and how log does that take (roughly)?

 

I've submitted my first and haven't heard back and just don't know if I should expect a response or not. No rush or anything obviously, just curious how it works.

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Out of curiosity, should I expect a response when I submit a destroyed mark to Deb, and how log does that take (roughly)?

I submitted a destroyed mark (HV7518, UPPER MARLBORO CO CTHSE SPIRE, photo) in late December. It was posted to the NGS database last week.

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For the most part you will only hear back if they do not mark it destroyed. If they do, you can check it online after 2 weeks or so.

I submitted KW3089 on Feb 9 and noticed today it is in the NGS database as destroyed: NGS KW3089

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How far does photographic evidence go in "proving the negative" of a destroyed mark and do those photographs have to coincide with the other submittal standards?

 

I submitted GG0426 as destroyed on GC.com, but am I going to need more proof to submit the same report to the NGS?

Edited by marvin1226

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I would submit your e-mail and the response from the school district to deb brown. Ask her if she needs additional info. I suspect you have enough though.

 

-Casey-

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My understanding is that it is easier to get intersection points (those towers, spires, tanks, chimneys, etc) listed as destroyed than markers. I culled out a group of markers in Missouri that had refereneces in their description to being destroyed. I sent them off to Deb Brown without any further documentation. She accepted some of them and gave me this guideline:

 

"In the future, if you come across any text that says the station is actually destroyed (not just "will be" or "possibly") and the reporting agency is NGS or a state related then those would be the ones to let me know about."

 

Sometimes we find stations that actually mentioned that they were destroyed but are still listed as not found. This helps us determine when we can easily have them officially changed to destroyed.

Sorry to dig up this old, old thread, but is this still the case? There are many such marks reported destroyed around here but not marked as such in the NGS database. (I checked.) Should I e-mail Deb about them?

 

SLer

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My understanding is that it is easier to get intersection points (those towers, spires, tanks, chimneys, etc) listed as destroyed than markers. I culled out a group of markers in Missouri that had refereneces in their description to being destroyed. I sent them off to Deb Brown without any further documentation. She accepted some of them and gave me this guideline:

 

"In the future, if you come across any text that says the station is actually destroyed (not just "will be" or "possibly") and the reporting agency is NGS or a state related then those would be the ones to let me know about."

 

Sometimes we find stations that actually mentioned that they were destroyed but are still listed as not found. This helps us determine when we can easily have them officially changed to destroyed.

Sorry to dig up this old, old thread, but is this still the case? There are many such marks reported destroyed around here but not marked as such in the NGS database. (I checked.) Should I e-mail Deb about them?

 

SLer

 

 

Yes that is still the case.

 

-Casey-

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A note drilled into this conversation by PFF in the general benchmarking forum is that officially DESTROYING a station in the NGS database removes information that is useful for other stations, particularly the box score which may list useful non-PID stations, or tie-ins in the description. A cautionary note.

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I think what I'll do is create a list, and separate it out into reporting agency and potential usefulness (like BuckBrooke said), and send it out when I get a whole bunch. Thanks!

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A note drilled into this conversation by PFF in the general benchmarking forum is that officially DESTROYING a station in the NGS database removes information that is useful for other stations, particularly the box score which may list useful non-PID stations, or tie-ins in the description. A cautionary note.

Can someone explain this further?

 

At first blush my reaction is that I'm trying to get their database to match reality. If the landmark is gone, it's gone and should be noted as such. If it has an adverse affect on the datasheets of nearby marks, that's a fault in the system, not something I should really concern myself with. It should be noted that you can still pull up sheets for destroyed marks if desired, so they aren't really gone.

 

Can anyone educate me?

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We agree that the goal is to improve the information content of the data base. The point being made in the other thread was that adding a Not Found report with an explanation of what had happened to the mark or its area might add more information than a simple "Destroyed". Those notes can at times record things that you would want to know when looking for other marks in the area. After the information is added, NGS could at some time in the future reclassify it as destroyed if they wish to, but at least the information is archived.

 

Cleaning up the data base by marking them destroyed will reduce the number of useless ones that show up when a user searches the data base for marks relevant to their project. That is nice, not necessary, because the Not Found information will alert them of the situation. It may take them a few minutes longer to read the extra data sheets, but it still avoids the big cost of them doing their own search in the field.

 

So I conclude that it is a tradeoff. If there is nothing useful to put in Not Found notes, then a simple Destroyed is a little better. If there is something else worth recording, then the Not Found is a lot better.

 

Changing a mark's status to destroyed does not affect other data sheets. It just makes it a little harder to find the data sheet with the Not Found notes and "box score". There are ways to search but it is harder if you don't know the PID.

 

The box score is a list of bearings and distances from the mark on this data sheet, if it is a triangulation station, to other points. If you are looking for one of those other points that is not a triangulation station, this information can be useful.

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The point being made in the other thread was that adding a Not Found report with an explanation of what had happened to the mark or its area might add more information than a simple "Destroyed".

Ah, so the preferred way is to log a "Not found" and then send the email to log it as destroyed. OK, that makes sense. I have noticed on the PID that I've "destroyed" that it contains only a notation that it has been reported. None of the information I've passed along has been included.

 

There are ways to search but it is harder if you don't know the PID.

As far as I know all the same searches on the NGS page are available, you just have to check the box that you want to see destroyed marks as well.

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My opinion from the point of view of being in the survey field for 30 yrs. You should be extremely careful with logging marks as destroyed unless you can prove without a doubt it is. If you cannot find it and you are 99.9% sure it destroyed, its should not be logged destroyed. Without evidence, such as the broken monument with the survey dish attached, its not found..

 

Best to just call it not found and add a statement that fits the amount of effort extended to find the mark:

 

A THOROUGH SEARCH REVEALED NO EVIDENCE OF THE MARK.

 

or

 

THERE HAS BEEN ROAD WORK AT THE LOCATION, ASSUMED DESTROYED.

 

or something along these lines.

 

btw-Calling it destroyed does not mean NGS will toss out the data. It will still remain in archives. On more that one occasion marks reported destroyed later turned out to be reported in error. Not only is a survey mark of value but the data related to the mark is also. So just because its gone does not mean it does not provide any useful information. I can go to the local EDU archives (have in the past) and they have survey records going back to the 1800's on work that is long gone. We found some old 1890's records of surveys done to determine in which county a murder was committed so as to determine who could hang the person for the crime and if they could have hung him 2x, I am sure they would have.

Edited by Z15

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I recently had a mark destroyed, but I wanted some comments in the data sheet that could be pulled up should anybody want to in the future. Thus, I did a "not found" on it, then followed up with a photo to Deb Brown. It seemed logical, but she sent me an email saying basically, don't do that. Don't file the not found, just send the email asking for it to be destroyed.

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My opinion from the point of view of being in the survey field for 30 yrs. You should be extremely careful with logging marks as destroyed unless you can prove without a doubt it is. If you cannot find it and you are 99.9% sure it destroyed, its should not be logged destroyed. Without evidence, such as the broken monument with the survey dish attached, its not found..

 

Best to just call it not found and add a statement that fits the amount of effort extended to find the mark:

 

A THOROUGH SEARCH REVEALED NO EVIDENCE OF THE MARK.

 

or

 

THERE HAS BEEN ROAD WORK AT THE LOCATION, ASSUMED DESTROYED.

 

or something along these lines.

 

btw-Calling it destroyed does not mean NGS will toss out the data. It will still remain in archives. On more that one occasion marks reported destroyed later turned out to be reported in error. Not only is a survey mark of value but the data related to the mark is also. So just because its gone does not mean it does not provide any useful information. I can go to the local EDU archives (have in the past) and they have survey records going back to the 1800's on work that is long gone. We found some old 1890's records of surveys done to determine in which county a murder was committed so as to determine who could hang the person for the crime and if they could have hung him 2x, I am sure they would have.

 

I've logged one (SY3195) as destroyed with NGS. This was an extremely clear case of mark not existing, but the descriptive text was absolutely spot on with where it should have been. The sidewalk had been replaced and there was no mark.

 

Another one I logged as "NOT FOUND" (SY0867), even though I know for a fact it's completely gone, because the descriptive text takes you from an intersection to a point almost 200 feet away. I found the fire hydrant but the rest of the area has been redeveloped- it's no longer oil tanks but real estate offices. :P

 

For the first one I felt fine about submitting it as destroyed, because it was absolutely clear the mark was not there and never would be. The second one I left be with a NOT FOUND because there was a chance, however small, that I screwed up.

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Here is one we found a long time ago (1980's).

 

We were looking for this USGS BM at an intersection with US HWY 41 and could not find it. The road had been reconstructed in the 1950s and we assmumed it was destroyed, so we moved on to another. Some time later we were leveling thru area of the missing mark and the boss said, put a RR spike in that pole and set a TBM. We see if it buried or what. So we set a RR spike at the base of the pole. Weeks later after the field work was competed it was determined the spike was about 2 ft higher than the BM elevation. This intersection was completely different than before but we had a house as reference and the construction plans which did not show the BM. So we go out there and see if we can find it. No luck. Next day Boss says, did you find it? NOPE. So he wants to go back out and look again but I had to go somewhere (DDS) so he took a intern. I got back later that day and walked in the field office and the boss was sitting there with a big grin on his face. They found it buried. They dug a bunch of holes and got lucky. They even were able to extablish the old street C/L and that gave them a 2nd measurement to go from. Spent lot of effort, 2 days and 4 different people looking.

 

I was sure it was gone.

 

We placed a 12in metal culvert pipe around it and had a metal cover made.

 

btw-We checked the elev and it was right on.

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