question about logging a BM

[+Astro_D]

Finally got back out BM hunting for the first time this year. Yeah, I know. its about darned time.

 

Well, we got to the coords for PN0722 BM.... and did not find a trace of it. We read the description and still could not find it.

 

However, we did find a K219 Reset 1987 Benchmark disk at the location described for K219. We looked in the country records and could not find any indication of a reset being submitted.

 

On the road was spray painted BM 701 with an arrow pointing to the BM.

 

We think we shuold log this a DNF, but add the pixs and comments about the reset being located.

 

Any suggestions about what to do or where else we could look to see if the reset was submitted?

[Bill93]

How carefully did you measure from the corner of the school? Does the school building have a recent addition that would confuse where the corner was? The NGS data sheet has these excellent reports from the Power Squadron:

 

PN0722 STATION RECOVERY (2002)

PN0722

PN0722'RECOVERY NOTE BY US POWER SQUADRON 2002

PN0722'USING DIRECTIONS GIVEN WOULD PUT THE LOGO CAP UNDER BLACKTOPPED SCHOOL

PN0722'DRIVEWAY. SIDEWALK AND STREET WERE WIDENED.

PN0722

PN0722 STATION RECOVERY (2002)

PN0722

PN0722'RECOVERY NOTE BY US POWER SQUADRON 2002 (DRB)

PN0722'NOT FOUND. THE AREA HAS BEEN RE-LANDSCAPED. STATION MAY BE UNDER

PN0722'GROUND LEVEL.

 

I would guess that when work was planned for this area the engineers did a reset before taking out or burying the original mark, which was a rod under a logo cap, with the reset being a disk they had on hand put into some concrete in a hole they dug nearby. I couldn't tell exactly from your picture what the concrete was.

 

I rechecked the NGS data base with a search for a mile around the coordinates, and saw no reset mark. We know there is often a long time between field work and the information showing up on the NGS data sheet, if it ever gets submitted at all.

[Wintertime]

Astro, you did exactly the right thing. I've seen all too many cases where people have "found" a benchmark that was the wrong type, in the wrong location, from the wrong year, the wrong size, etc. They weren't paying attention that what they found was a reset, or another survey mark from another agency that just happens to be in the same general area as a now-destroyed mark. You figured out that what you saw was not PN0722, and thus PN0722 had to be logged as a "Not Found." Good work!

 

Patty

[mloser]

That brings up the question of the painted BM on the road, which implies that a surveyor used it for some purpose. Either the reset mark is listed with an agency that is not the NGS (states and counties often have their own marks that don't get into the NGS database, but we have already ruled out the county from what was said here), or the reset has been used as if it was the original mark, which would be a mistake. This isn't the first time I have seen that sort of thing, but it makes me wonder what effort some of the survey crews put into finding these marks.

 

I found AB6521, broken and upside down, yet painted pink, with a notation on the road beside it. This mark was a first order horizontal control mark, so no matter where it was "replaced" after whatever accident broke it off, the accuracy was completely compromised. And that assumes that it was replaced exactly where it was broken. I saw no evidence of the remainder of the base. The mark is unusable and has been declared destroyed.

[68-eldo]

That brings up the question of the painted BM on the road, which implies that a surveyor used it for some purpose. Either the reset mark is listed with an agency that is not the NGS (states and counties often have their own marks that don't get into the NGS database, but we have already ruled out the county from what was said here), or the reset has been used as if it was the original mark, which would be a mistake. This isn't the first time I have seen that sort of thing, but it makes me wonder what effort some of the survey crews put into finding these marks.

 

I found AB6521, broken and upside down, yet painted pink, with a notation on the road beside it. This mark was a first order horizontal control mark, so no matter where it was "replaced" after whatever accident broke it off, the accuracy was completely compromised. And that assumes that it was replaced exactly where it was broken. I saw no evidence of the remainder of the base. The mark is unusable and has been declared destroyed.

 

Maybe the survey crew uses a go-fer to find the marks so that the highly paid professionals are not wasting time tramping around in the weeds. The go-fer found and dutifully marked it. Just a guess.

[+RazorbackFan]

I have found several reset benchmarks in my area that aren't listed as such in the database. Two such examples are NB1570 and NB0296. These were both placed on bridges which have been replaced. I belive they were set by the NYDOT. Funny thing is they replaced 5 benchmarks on bridges along the same highway. 2 of them they replaced with NYDOT disks, and 3 were replaced with NGS disks. Furthermore of the 3 NGS disks, only 1 of them is correctly reported as being reset in the NGS data base.

 

Any how, more to the point, Deb Brown said to report any new NGS disks that have been reset and not in their system to Davey.Crockett@noaa.gov (no I'm not making this up!). I filed reports of not found for these disks and mentioned the location of the new reset disks in the writeup. Hope this helps.

[Wintertime]

Any how, more to the point, Deb Brown said to report any new NGS disks that have been reset and not in their system

Oh, did she? I didn't know that. I've got one or two for them, then. I'll have to take measurements to describe the location of one I'm thinking of, because it's a few hundred feet away from the original.

 

Patty

[+Astro_D]

Well, we went back to this benchmark today and did some measurements.

 

Here is our results:

 

28 Feet W from the NW corner of the school

 

15 feet SE from utility pole 88-23446 45-5

 

24 feet E from the fire hydrant

 

37 feet NW from the flag pole

 

2 inches E of the east end of the sidewalk

 

4 feet E from the curb of the east side of the street

 

The measurements on the data sheet say: 28 feet W of the NW corner of the school and 20 feet from the utility pole. We did go out 20 feet and came up with absolutely nothing. Not even a ping with the metal detector.

 

I am still thoroughly confused by this one. Ah, the fun of benchmarking. We will be updating our log with our measurements.