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Is this a replacement benchmark?


mchaos

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Okay, so there is a benchmark that has not been found near my home. I decided to give it a shot and see if I can find it. Its benchmark KV1408.

 

I searched for it and didn't find anything set in the curb as it said it would be, but the curb is fairly new. Probably done over a few times in 70 or so years. I did however find near where it should be according to the survey, a concrete monument. No markings on it, looked fairly weathered as very old concrete does. I took some pics as well. I want opinions. Could this be a replacement benchmark monument placed when the road, sidewalk and area had construction being done that would need to move or replace the benchmark???

 

This first pic is of the power line pole BL 141 as described on the benchmark page.

0617001410.jpg

 

Now here is the fire hydrant located more then the mere 5 feet that is suggested by information from the bench mark page. I guess that the pole had been moved during construction on road at some point in time because if the mark were in between them or near in between them, by measurements taken it would have to be in the ball park of 5 feet from each other.

0617001411.jpg

 

Now here is a pic of how far they are now apart. As the hydrant is in a hedge, I placed a bright orange marker in front of where it is located. its all the way to the right of the pic on the side walk.

0617001411a.jpg

 

Now here is the pic of the concrete monument in front of the power line pole BL 141.

0617001410b.jpg

 

And another pic showing the monument and the power line pole and identifier number.

0617001410a.jpg

 

And last but not least another pic of the monument at another angle.

0617001412.jpg

 

So what does everyone think? Can I mark this benchmark found???

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Well its not the benchmark I am guessing. I followed the original coordinates and found in the center of the road 11-13 feet from GZ an impression in the road from a round disk like object. Which has to be the benchmark.

 

Apparently a lot has changed like placement of power line poles.

 

0617001524.jpg

 

0617001524b.jpg

 

So I am guessing I mark this one as destroyed??

 

Now, is there any way to contact the agency to replace this? the spot is still clearly there.

Edited by mchaos
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You should not count a find unless you find the mark in the right place.

 

Also, by the NGS interpretation of "destroyed", you must find the mark anyway, but out of its place. In the case of this mark, you'd have to find the monel metal rivet in a broken piece of concrete curb in the hedge or somewhere like that. Otherwise you really can't be sure it is destroyed.

 

If you don't find the mark, then you should log as not found or didn't find it.

 

A monel metal rivet is only about 1/4 inch in diameter and silvery colored. According to the description it has to be on the curb, not in the street or anywhere else. Lots of times benchmarks are gone from curbs or sidewalks on corners because newer laws require ramps at corners, so corner curbs are removed and a ramp is put in instead.

 

This one's a not-found.

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>location is SCALED

 

This means that the coordinates will suggest where to park the car, but are of no further use.

 

>Marker Type: rivet

 

Note that the mark is described as a monel metal rivet (a silvery metal, usually a big fraction of an inch in diameter), not a disk. It was set in a curb some time before 1942, so if the curb looks newer than that the mark is gone. A replacement, if one exists, can NOT be logged as KV1408. A replacement would get its own data sheet and PID if it were reset to the tight standards and the information submitted to NGS.

 

I doubt the concrete post has any geodetic ("benchmarking") significance. It could be something put up to mark the right of way of the road, or something else entirely.

 

If the street has not been widened significantly, merely repaved, then the hydrant may still be in the same position, so that may indicate where on the curb to look. If the pole looks too new and the distances do not check, then it is likely the pole was replaced and not in the same spot.

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Well its not the benchmark I am guessing. I followed the original coordinates and found in the center of the road 11-13 feet from GZ an impression in the road from a round disk like object. Which has to be the benchmark.

 

The monel rivets are not disks. A number of rivets were set in the general neighborhood of Blairstown by the New Jersey Geological Survey (NJGS), and you can see what they look like in the logs for them: LY0744, LY0743, LY0738, KV1410.

 

Quite a few other rivets have been destroyed by time and weathering, and they haven't been replaced or reset.

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Well here is the thing. the scaled coords brought me up the road where that impression was. What was the impression from?

 

The road has been widened. The hydrant is there but 80 feet from where the original coords take me.

 

there is no way this rivet is here. I changed my log to did not find it.

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Forget the coordinates. Scaled coordinates cannot be trusted. They are truncated to whole seconds, which is 70 or 100 feet of uncertainty at best, and they were taken off of paper maps with a scale, giving some more uncertainty, and the point on the map may have been picked incorrectly due to ambiguities in the description or changes to roads, etc. made between the year the description was written and the year the scaled values were derived.

Edited by Bill93
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It is not uncommon to find another benchmark in the general area of an old one that is gone. It's almost as if the old benchmark was missed and someone put another one near there. However, even if there was a disk where you found just a circular impression, that would not be a find of KV1408 because KV1408 is a rivet, not a disk.

 

It is even possible that the circular impression once had a reference mark disk. However, finding a reference mark is not a find of the station it is a reference to.

 

Your current log of 'couldn't find' is correct. If all of us answering went there, that's what we'd all log too.

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mchaos,

 

Thanks for changing your log to NOT FOUND. It actually may be down there under added fill for "street improvements". There are several instances of long lost marks reappearing under structures built and removed.

 

Interesting "HISTORY" will disappear when a monument is "DESTROYED" by NGS.

 

1f2da760-5b4b-4323-9435-7f1491f34240.jpg

KU3532

 

TOO BAD! MEL

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Interesting "HISTORY" will disappear when a monument is "DESTROYED" by NGS.

No, not really - you can still get to it on the NGS website by doing a PID search. I believe. :)

No the problem is not getting the datasheet - you can always get destroyed mark datasheets - the problem is, the NGS deleted all the entries after 1932, which contained a wealth of interesting history. In fact the first entry after the destroyed one (also from 1932) explained why it wasn't really destroyed. And they didn't do it long ago, they did it sometime after 2006, when I recovered the mark shown in the picture. The NGS datasheet was still full in 2006.

 

Compare the copy of the datasheet saved on GC.com with what's left on the NGS site.

Edited by Papa-Bear-NYC
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Well, to keep this circular reference going, can anybody access a current DESTROYED DS for this one:

 

3454f601-dca2-40fd-86a1-f486d0ada790.jpg

 

SK0183

HH2 that I used in my recovery for both FOUND CAP and the NOT DUG FOR BOLT: SK0181'HH2 471559.40 943741.30

 

It was still there when I did the recovery in November last year. A second GHOST CAP SK0180 was DESTROYED in 2001 and it's DS can be retrieved.

 

Might be a bit hard to home in on the underground mark SK0181 if the cap on pipe really is gone. MEL

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Interesting "HISTORY" will disappear when a monument is "DESTROYED" by NGS.

No, not really - you can still get to it on the NGS website by doing a PID search. I believe. :lol:

No the problem is not getting the datasheet - you can always get destroyed mark datasheets - the problem is, the NGS deleted all the entries after 1932, which contained a wealth of interesting history. In fact the first entry after the destroyed one (also from 1932) explained why it wasn't really destroyed. And they didn't do it long ago, they did it sometime after 2006, when I recovered the mark shown in the picture. The NGS datasheet was still full in 2006.

 

Compare the copy of the datasheet saved on GC.com with what's left on the NGS site.

I've been confused about this "disappearing data" for some time now and PapaBear's example is a real eye-opener!

What's the reasoning behind this? - Can anybody from the NGS please explain? :)

 

~ Mitch ~

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Interesting "HISTORY" will disappear when a monument is "DESTROYED" by NGS.

No, not really - you can still get to it on the NGS website by doing a PID search. I believe. ;)

No the problem is not getting the datasheet - you can always get destroyed mark datasheets - the problem is, the NGS deleted all the entries after 1932, which contained a wealth of interesting history. In fact the first entry after the destroyed one (also from 1932) explained why it wasn't really destroyed. And they didn't do it long ago, they did it sometime after 2006, when I recovered the mark shown in the picture. The NGS datasheet was still full in 2006.

 

Compare the copy of the datasheet saved on GC.com with what's left on the NGS site.

Aaah. I can't speak for the NGS (but I do work close enough to throw something at DaveD's window) - but I'm guessing that was an 'oops', meaning it wasn't supposed to happen. All the ones I have marked as destroyed have had their histories remain intact. ..

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