Jump to content

Benchmarks Not Found - Mark Destroyed?


Recommended Posts

I'm finding that benchmark hunting results in a LOT of history like, "STATION RECOVERY (1962)

RECOVERY NOTE BY US GEOLOGICAL SURVEY 1962 MARK NOT FOUND."

 

These are marked with "?" marks when you search an area. I've started logging these as "Destroyed" . . .

 

Is this the right thing to do when the USGS was not able to find them and they haven't been seeen since?

 

JohnTee

Link to post

I would advise against that. We have found 3 that the USGS did not find & 12 that the NGS did not find. Then there is the power Squadron!

 

They may just have been having a bad day then and couldn't find it. We have had several that took at least 3 tries to find and when we did find them the description made complete sense, then!

 

John

Link to post

Then, there are the four that we found recently that NJGS did not find on 2/20/1992. One of them was right in the sidewalk, 5.5 feet north of the fire plug. I'm starting to think that this guy was otherwise involved that day, and filed the Not Founds as a way to cover his tracks! Almost as poor a record as the Power Squadron! But, find them, we did.

Link to post

I side with the others. Just because NGS or USGS didn't find a mark doesn't make it unfindable. I located one from 20 feet away last week that was a 1956 NF, and have at least 5 others like that to my credit. In fact, just because I can't find it doesn't mean it is destroyed. It may be underground, for instance and you just can't see it. Just like oldfarts, there are marks I have returned to multiple times because I just didn't think they could be gone. KW0169 took two visits, KW0765 took 3, and KW0931 took 4. It helps to be obsessed I suppose...

Link to post
Is this the right thing to do.....
No it isn't. You should delete those logs. If you do physically go to these locations, you can, of course, add your own Not-found report. B)

 

Even more extreme, there are many cases in the NGS database that say very clearly and explicitly that the mark is gone, sent back to the NGS, blah blah blah. But still, the item is not coded as Destroyed by the NGS (for whatever reason). Deb is reported to have said (or she did say in this forum herself, I forget which) that she would appreciate being emailed about such cases so she can consider marking them as destroyed. We have discussed those cases in the forum a while back, considering whether ot not it's a good idea to code them as Destroyed in the geocaching copy of the database. As I recall, the consensus was that it's only reasonable to do that if you physically go to the site and check out the situation yourself.

Link to post

I use the same standard here as for NGS. If you can't find the remains of the disk and take a photo of it, don't log it destroyed. And if you can, follow the procedure for getting it properly destroyed by the NGS as well. Some of these things are simply miserable to find, and because somebody else didn't find it, doesn't mean it's gone. As for logs without having been to the site and invested some time and effort, I'm completely against that. What's most useful are detailed comments describing what was done, even if you didn't find it.

Link to post

I'll repeat what everyone else has said: it's never appropriate to make a log entry for something you haven't visited personally.

 

There was a thread a while back about the various marks we've found that had been previously reported "not found." You should look at some of the pictures to see how ridiculous some of the old "not found" reports can be. See the "Most obvious finds" thread.

Edited by holograph
Link to post

I use the same standard here as for NGS. If you can't find the remains of the disk and take a photo of it, don't log it destroyed. And if you can, follow the procedure for getting it properly destroyed by the NGS as well. Some of these things are simply miserable to find, and because somebody else didn't find it, doesn't mean it's gone. As for logs without having been to the site and invested some time and effort, I'm completely against that. What's most useful are detailed comments describing what was done, even if you didn't find it.

I have a slightly different standard, I treat disks on structures the same way I treat intersection stations. If a disk is mounted on a building, and after visiting the site I conclude that the building is gone (turned into a parking lot, etc.) I log it as Destroyed on GC, and Not Found with the comment "Presumed Destroyed" (with a discription of what I found) on NGS. Same with intersection stations - if the steeple, stack, etc. is gone, I log it the same as the above.

 

If I can't find the disk for any other reason than that the structure is gone, I log it Not Found both places.

 

For example, yeterday I searched for a disk on a bridge sidewalk. The roadway had clearly been widened at the expense of the sidewalk (the description said the sidewalk was 14 feet wide, it's now 7 feet wide). So since the bridge was still there, and there still was a sidewalk I logged it as Not Found even though in my heart I am sure it was destroyed. Another mark down the road was set on a column of a restaurant entrance. It's now a parking lot. So that one got logged as Destroyed.

 

As for logging something based on some one else's log, never. But of course if 17 others have logged Not Found, and you couldn't find it either, you don't feel so bad, and if you do find it after the 17 failures, you feel great. Right now I asking Deb to mark a station which was marked Destroyed by the NGS in 1974, as Not Destroyed. We'll see how that one goes.

 

Does any one else search for marks which have already been declared as Destroyed? I've found two.

 

Distinctions, distinctions. They make life interesting.

Edited by Papa-Bear-NYC
Link to post

Papa-Bear,

I recently added the local destroyed marks to my Mapsource database so I could look for them in my travels. So far I have looked for about 5 of them and am convinced the status is valid.

Link to post

I sent Cheryl a picture of MG0512, in good condition and exactly matching the description, but they did not un-destroy it. I have no idea if they investigated it or what they might have in their records beyond the data sheet.

Link to post

Yes, I certainly have found discs listed in the NGS database as destroyed. See THIS THREAD from just two weeks or so ago. You have to wonder how this happens, especiallly when the reporting agency was NGS, and the mark is obviously right where it is supposed to be. "Administrative" error (i.e. mistake)? Found to not be surveyed properly, well after it was added to database?

 

EDIT 10 minutes later: I just went back and looked again at the "destroyed" markers I found (see link above). They are no longer destroyed!! I will SWEAR (under oath) they WERE destroyed! I probably have a printout of the the datasheet at home (I'm at work now), for when they were destroyed. OK, someone at NGS (Deb? Cheryl? Casey?) read my thread and fixed the database. WOW! I'm impressed, and thank you very much!

 

[Edit later same day: Yes, I DO have a printout showing DX3251 used to be destroyed]

 

Now if we could just get GC.com to add them to their database, I could log two more old finds for the contest. Yeah, riiiiiight!!!!

Edited by Klemmer & TeddyBearMama
Link to post

There are a couple destroyed stations around here I want to look for, but I have reservations about trying to get a found station un-destroyed. My fear is that somebody knew something when it was destroyed, that we don't. In the same way as it's so hard to get a disk destroyed, I think a similar standard (not sure exactly what) has to be applied to reverse the process. Here's a hypothetical example. Say the station I recently found in a broken and horizontal condition was replanted by a nearby home owner (he initially wanted to do this). Without being re-surveyed, you'd have absolutely no way to know that it wasn't in its original position. Ah, if monuments could talk!

Link to post

There are a couple destroyed stations around here I want to look for, but I have reservations about trying to get a found station un-destroyed. My fear is that somebody knew something when it was destroyed, that we don't. In the same way as it's so hard to get a disk destroyed, I think a similar standard (not sure exactly what) has to be applied to reverse the process. Here's a hypothetical example. Say the station I recently found in a broken and horizontal condition was replanted by a nearby home owner (he initially wanted to do this). Without being re-surveyed, you'd have absolutely no way to know that it wasn't in its original position. Ah, if monuments could talk!

This is my thought exactly. One of the marks I found was a benchmark mounted in a stone wall (see KV0584, which includes my recovery). The distances to nearby reference points are all correct (these were verified in 1995 by the NJ Geodetic Survey). But what if in 1974 someone took the wall down, fidddled with something (electric, water, whatever) then put the wall back where it was. Certainly from a surveyor's perspective, the mark is now destroyed.

 

This is why I wish they would put exactly why a mark is declared destroyed when it gets set. At the moment we are asked not to make a detailed report before asking for a mark to be destroyed, which is too bad. It would help future surveyors if they should find such a mark.

Edited by Papa-Bear-NYC
Link to post

I agree completely with the last two posts. Which is why I had not yet asked NGS to "un-destroy" those two marks. I was considering those kinds of possibilities (although it does not seem at all likely in those two cases). Meanwhile, NGS did it anyway. I can only fall back on the obvious fact that they know things we don't, and leave it at that. I guess....

Link to post

I also agree. My guess it that the NGS feels the criteria for setting a status to Destroyed are so stringent that no explanation is necessary. We have discovered that is not the case, and that it would definitely be beneficial for a final Not Found description to explain the status.

 

I think we (GEOCAC) may be the group most concerned with this and the only ones likely to report on the destroyed status if the NGS accepted it.

 

As you can see by the many Not Found recoveries with no text, there is a dearth of information on NF marks. How easy it is to say "Bridge replaced" or "Road widened" to help the next person decide if they want to bother to follow up on your recovery or let it go. With an explanation-free Not Found a later hunter must either 1) assume the previous recoverer did everything in his/her power to find the mark and that their powers were pretty extensive, or 2) assume the recoverer did little searching at all and the mark may well remain. Both assumptions are bogus. Reality is somewhere in between, and the more descriptive you can be the better chance a surveyor has of deciding how to handle a given mark before he goes out in the field.

Link to post

I'll repeat what everyone else has said: it's never appropriate to make a log entry for something you haven't visited personally.

 

There was a thread a while back about the various marks we've found that had been previously reported "not found." You should look at some of the pictures to see how ridiculous some of the old "not found" reports can be. See the "Most obvious finds" thread.

 

Ooh! Is that an invitation to show what the NJGS misses on a bad day? :)

60f90a82-687e-42e5-992f-3c188484a8e1.jpg

KU1648

2c0461fe-569e-47db-a5cd-c37ac81af163.jpg

KU4055

Link to post

Harry, that KU1648 find is classic. The description was "4.0 FEET EAST OF A 6 FOOT HIGH ROCK

WALL, 5.5 FEET NORTH OF A FIRE PLUG, 1.8 FEET WEST OF WEST CURB OF RIVER ROAD", and your photo shows all of them! The fire plug is hard to miss.

 

I guess that team that "SEARCHED FOR AND NOT RECOVERED AFTER A QUARTER HOUR SEARCH BY A TWO MAN PARTY" must have been searching for it in the bottoms of their beer mugs in the nearest bar. :)

Link to post

I'm finding that benchmark hunting results in a LOT of history like, "STATION RECOVERY (1962)

RECOVERY NOTE BY US GEOLOGICAL SURVEY 1962 MARK NOT FOUND."

 

These are marked with "?" marks when you search an area. I've started logging these as "Destroyed" . . .

 

Is this the right thing to do when the USGS was not able to find them and they haven't been seeen since?

 

JohnTee

 

I've found six or more that had recovery notes stating the mark was not found. They were all very easy to find and the descriptions were dead-on accurate and there was not likely any thing that would have obscured them. Seemed to me that there was some requirement or reward for writing recovery notes for marks in a local area and the team decided bypass several of them but yet still post a note.

Link to post

... As for logs without having been to the site and invested some time and effort, I'm completely against that.

 

But there are times where there is no doubt. When the description clearly states the disk was mounted in a building or a bridge and it is quite obvious that the structures have been completely destroyed then, for gc.com purposes, it is clearly ok to mark them as destroyed.

 

I know the 1947 Noyo Bridge in Fort Bragg, CA was completely demolished and a new bridge constructed in its place. Therefore I can log the two benchmarks as destroyed so people won't log the new disks in the new bridge (not yet listed on gc.com) as found.

 

I also know the two 100' tall Georgia-Pacific smokestacks were completely destroyed, one in the 40's and one in the 80's. A Benchmark hunter logged them both last year and supplied photos of two current (but now also demo'd) 40' tall stacks. So it is best for me to log them both as destroyed.

Link to post

 

But there are times where there is no doubt. When the description clearly states the disk was mounted in a building or a bridge and it is quite obvious that the structures have been completely destroyed then, for gc.com purposes, it is clearly ok to mark them as destroyed.

 

I know the 1947 Noyo Bridge in Fort Bragg, CA was completely demolished and a new bridge constructed in its place. Therefore I can log the two benchmarks as destroyed so people won't log the new disks in the new bridge (not yet listed on gc.com) as found.

 

I also know the two 100' tall Georgia-Pacific smokestacks were completely destroyed, one in the 40's and one in the 80's. A Benchmark hunter logged them both last year and supplied photos of two current (but now also demo'd) 40' tall stacks. So it is best for me to log them both as destroyed.

Even if it's an established fact that a structure is gone, I will still go look. For example the Singer Building (KV4399), once the tallest building in the world was demolished in 1968. Googling "Singer Building" will reveal plenty of information about it.

 

Nevertheless I went and looked, not so much to make sure it was gone, but also to see what is there now. When I submitted a "Destroyed" report to Deb, I submitted a vitage picture of the original and my picture of the present building.

 

Don't be lazy. Go to the site and take a look. Take a picture of that high-rise, that condominium, that ugly mall, that parking lot. Just do it. (Not meant to be a rant. Just my opinion.)

Link to post

This is my thought exactly. One of the marks I found was a benchmark mounted in a stone wall (see KV0584, which includes my recovery). The distances to nearby reference points are all correct (these were verified in 1995 by the NJ Geodetic Survey). But what if in 1974 someone took the wall down, fidddled with something (electric, water, whatever) then put the wall back where it was. Certainly from a surveyor's perspective, the mark is now destroyed.

 

Pardon my ignorance...I'm relatively new to this, and am NOT a surveyor, so this is an honest question. How do surveyors use these marks, exactly? How exactly are marks set, and with what accuracy? If the descriptions and measurements are correct...I guess my question is how exact is the position to begin with, and in relation to what? Obviously some of the coordinates listed for marks are nowhere close.

 

For example, I logged RK0411 on Geocaching. The coordinates listed in the datasheet put the mark roughly 500 feet south of its actual location. On the opposite side of a four-lane highway, and the opposite side of the cross street. I guess my confusion is that if a datasheet has scaled coordinates that are hundreds of feet off, if the description and measurements match, how much more accurate does it need to be? Again, this is an honest question--I am trying to learn here.

Link to post

andylphoto,

 

There are two ways that surveyors use the marks. One way is for establishing geographic position (latitude and longitude), and another way is for establishing elevation. The first is called horizontal control, the second is called vertical control.

 

Obviously, if the surveyor is only using a mark to establish elevation, he is not overly concerned about the precise location in terms of latitude and longitude -- all he needs is enough information to find the mark and use it for levelling. Thus, when many vertical control marks were established, the latitude and longitude were estimated but not measured, and the datasheet shows the position as "scaled", meaning it was probably plotted on a map and the position estimated from the map coordinates. That kind of position is often off by several hundred feet, but the surveyor will use the description to find the mark, not the coordinates. The elevation of the mark will be accurate to within a few cm.

 

If the station is rated for horizontal control, it's position has been precisely determined and you can count on it being where the datasheet says it is. Surveyors use horizontal control for mapping purposes or for establishing other points that need to be precisely positioned. For instance, aerial survey companies often place large markers on horizontal control stations so that they can spot them in the photographs and calibrate the photos. Many of the older horizontal control stations were part of triangulation networks that were used to measure and map the country. Nowadays, horizontal control stations are also often used with differential GPS surveying to provide base station data that can be combined with the data at a second location to compute the precise location of the the second location.

 

The accuracy of the position varies depending on the "order" of the station. "First order" stations are very precisely located and are used as the primary reference for other stations that are slightly less accurately located. The datasheet tells you the order of the station.

 

For the purposes of our hobby, we just look at the datasheet and look at the position. If it says "adjusted" it indicates that it's position is known to better accuracy than our GPS receivers have. If it says "scaled" it means that the position is a rough estimate that can be off by many hundreds of feet.

Link to post

Thanks holograph.

 

I guess my erroneous assumption was that most were used for horizontal control. I had read about the difference between scaled and adjusted, but now looking back over the ones I've logged, it appears more (that I've looked for anyway) have adjusted elevations than locations, so would be for vertical control.

Link to post

Andylphoto:

I would say it is not uncommon for an area to have many more vertical (scaled) marks than horizontal (adjusted) marks. I shouldn't generalize too much, but from my experience (just from memory), and mostly in southern CA, I would guess there are 5 to 1 more vertical (scaled) marks, compared to horizontal (adjusted) marks.

Link to post

Here in upstate NY it might be more like ten to one in favor of vertical control. By luck I do have a HARN station just up the road from home, and another one on the way to work, but the vast majority are 1943 elevation benchmarks, and some railroad survey rivots that were likely placed in the 1800s.

Link to post

Thanks for all the answers guys. I think they were pretty unequivocal. I've gone back in, edited all of the 'Mark Destroyed' logs to 'Did Not Find', but two. I hope I didn't throw TOO big a wench into the monkeyworks! That leaves questions on two.

 

HB0981 was part of the Cape Girardeau Mississippi River Bridge, which has been demolished.

1/1/1981 by NGS (GOOD)

RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1981 IN CAPE GIRARDEAU, AT THE STATE HIGHWAY 146 BRIDGE OVER THE ST. LOUIS SAN FRANCISCO RAILROAD AND THE MISSISSIPPI RIVER, SET VERTICALLY IN THE WEST FACE OF THE NORTH CONCRETE CIRCULAR PIER OF THE FIRST PIER STRUCTURE OF THE BRIDGE, 18.89 METERS (62.0 FEET) EAST OF THE EAST RAIL OF THE TRACK, 16.45 METERS (54.0 FEET) EAST-SOUTHEAST OF BENCH MARK RM 41 USE, 15.54 METERS (51.0 FEET) EAST-SOUTHEAST OF THE SOUTHEAST CORNER OF THE SOUTH END OF A CONCRETE FLOOD WALL WITH A METAL FLOOD GATE. THE MARK IS 0.91 M ABOVE THE GROUND.

 

Mocassin Springs Reset HB1738says, "STATION RECOVERY (1991)

RECOVERY NOTE BY MO DEPT OF NAT RES 1991 (BDC) MONUMENT FOUND OUT OF GROUND, DISK REMOVED AND RETURNED TO MODNR OFFICE. "

 

Where do I go to get my wrist slapped? :laughing:

 

JohnTee

Link to post

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...