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WD4JKH

Looking for marker information

16 posts in this topic

Posted (edited)

30 some odd years ago I saved this marker and concrete monument from a dumpster. I'm sure the only reason it wasn't IN the dumpster was it's weight. 

It sat at our old house until last week because the house was sold and I now have moved it to a corner of our present yard.  

I have searched and searched but have not been able to find any information on it and I sure would like to know where it was originally placed.

The markings I read are TT 28 K

Thanks for any help..

 

marker1.jpg

marker2.jpg

Edited by WD4JKH
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Posted (edited)

WD4JKH,

 

A few clues such as state & county where you first found it.  Maybe zoom in on Google Earth to about where that dumpster was and give us that Lat/Long.  Was there a somewhat nearby road or box store work in progress at that time.  No secrets in this bench-markers forum, please.  kayakbird

Edited by kayakbird
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It was in Thomaston, Georgia just sitting in front of the building on the sidewalk. It was not mounted or secured in any way and the new owner didn't like it so with a set of hand trucks he hauled it to the dumpster in the alley behind the building.

location.jpg

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Using the National Geodetic Survey Data Explorer centered on Thomaston, there are five USGS marks within a 25 mile radius that use a similar naming convention. Yours is not on the sort-able drop down 'View List'.  DG0963  TT 9A was last logged, with photo, in 2016.

 

Like many USGS marks that are not in the NGS Data Base, you may be able to get information from your regional USGS office.   kayakbird

 

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Thanks for your efforts. I wasn't sure if it was even from the area. 

 

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I don't think there is any easy way to find info on this if its not in the NGS database.   Without a more accurate location (Lat and Long) of where is was set (not found) you would never know to search the reams of data sheets USGS has for the USA.   The per-verbal needle in the hay stack.   

 

Try contacting 

USGS-Rolla, MO

Office of Communications and Publishing

Science Information Services

888-ASK-USGS (275-8747)

 

Contact the USGS on WebChat and "Like" us on FaceBook

Follow @USGS on Twitter, and check our You Tube page.

Thematic USGS Social Media sites for States and Topics

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Note - USGS work went on over 100 yrs and they had a habit of reusing mark designations (TT28K) in later years.  I know when I search the NGS database for Michigan I often find several USGS marks with identical names in different regions.  That also makes is hard to determine the original location.  And another thing, some USGS work was not up to current standards (lat, long and elevation are way off actual) and do not warrant any preservation.   

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Thanks for your information. I will dig further with your sources when I get a chance. 

Maybe even if the designator is reused, maybe the set date of 1933 will help?

 

 

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I was able to get scanned copies of control diagram sheets from USGS Rolla. I just told them which specific USGS quad sheets I was interested in and they emailed me a scanned copy. It's a list of written descriptions of each benchmark in each quad, and some have a basic diagram also. The description usually includes what was stamped on the disk (the ones I looked at typically had the "TT" designation like yours has). I was able to find a temporary bench mark (copper washer stamped USGS BM and copper nail from the 30's) that had fallen out of a rotten tree stump using the description from one of these sheets.

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Posted (edited)

Fyi - This info is in this forum somewhere but for those who don't down know.

USGS Marks stamped with the prefix "TT" designates "Transit Traverse".   

Also USGS marks with a 3 letter suffix, the letters are the Crew Chief initials.  e.g.  99 MPR

Edited by Z15
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aka   "The old fashioned way"

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Posted (edited)

 

On 7/20/2017 at 3:39 AM, Z15 said:

And another thing, some USGS work was not up to current standards (lat, long and elevation are way off actual) and do not warrant any preservation.   

I hope you are aware that there are different types of benchmarks. The two major divisions are vertical control vs. horizontal control. Historically two separate groups did horizontal vs. vertical controls and the two separate groups did not interact. For horizontal control the position was important, but the elevation was not. For vertical control the elevation was important, but the position was not. Positions of horizontal control were precise, but elevations not. Elevations for vertical control were precise, but positions not. Many positions for vertical control were obtained by reading the description to determine where that description placed the mark on a USGS topo map, then measuring the scaled position off the topo map with a ruler. That's what makes benchmark hunting so fun. The vertical controls were precisely leveled through and the horizontal ones were not. The position of a mark is not punched onto the mark, but shown on the datasheet and can be corrected. Elevations can change due to things like subsidence. Old vertical datums can become obsolete. Positions can change due to things like plate tectonics. Horizontal datums can differ significantly. If the datasheet isn't accurate, any surveyor can spend 4+ hours collecting GPS L1+L2 observations on the mark and submitting it to NGS via OPUS shared solutions. OPUS PROJECTS will be used for this purpose in the near future. Post 2022 or thereabouts I suspect very few benchmarks will warrant preservation as the NSRS will become active rather than passive. We're quickly reaching a time when most passive benchmarks will be a quaint legacy. Bill93 will be along shortly to correct me. :)

Edited by astrodanco
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Posted (edited)

Quote

I hope you are aware that there are different types of benchmarks

Picked up a little working as a DOT survey tech for some 30 yrs.  

Examples of USGS field work...

usgs-3_zpsqpqz2dhb.jpg

usgs-1_zps8aaicgzn.jpg

usgs-2_zpspmvlv0rx.jpg

 

Edited by Z15
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17 hours ago, astrodanco said:

 Post 2022 or thereabouts I suspect very few benchmarks will warrant preservation as the NSRS will become active rather than passive. We're quickly reaching a time when most passive benchmarks will be a quaint legacy

Good post.  

I would say though that the demise of passive bench marks will be gradual, and not all at once in 2022.  Much existing work on older datums will stay on them and even be extended on them. 

There are city sewer systems and (I think)  Corps of Engrs projects,even flood insurance maps on NGVD29, almost 3 decades after publication of NAVD88.

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On 8/2/2017 at 6:37 PM, Bill93 said:

 Much existing work on older datums will stay on them and even be extended on them.

Yup, the city where I live is stuck in NGVD29.

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