What is the PID on this benchmark?

[+Ken220]

I used to work with the US Forest Service during the summer as an educational specialist for the Youth Conservation Corps. I returned to an area I had worked in to locate a nearby geocache. While wandering around, I found a US Geological Survey benchmark dated 1933. It says the elevation is 501 feet with a "TT" stamped just in front of the 501. Beneath that is stamped 6P. Is the 6P the PID? I checked the PID "6P" with NGS and it is not listed. Any suggestions?

[+m&h]

U.S. Geological Survey disks are very rarely included in the National Geodetic Survey database. A second point to bear in mind is that PIDs almost never coincide with stampings or designations. In other words: there's probably no PID for this particular mark, but if there were, it would be in the database, not on the disk.

[+PFF]

Ken220:

 

Do a radial search on the NGS website, based upon the coordinates (or the coordinates of the cache, if you did not take a reading at the disk). Since this is a rural area, you probably can do a 1 mile radius, or greater, without getting too many marks in the results.

 

If the disk is in the database, this will give you the PID and a link to the datasheet. Look for a name of station which matches the stamping on the disk. It this case, it might be "TT 501". Or, something else might look familiar, like the "6P" you saw on the disk.

 

-Paul-

[Z15]

TT stands for "Transit Traverse"

 

I doubt the 501 is the elevation. It likely the station ID TT 501 No telling what 6P is but at times they do stamp siffixs suck as TT 501 TX or something to that effect. What was stamped in the disk was at the descretion of the Survey Chief in charge.

 

Do you have a photo of it to share?

 

 

PID is the computer database assinged code. Stands for Permanent IDentifier

 

The U.S. Geological Survey (USGS), an agency in the Dept. of the Interior has the responsibility for producing our national topographic maps. They completed the monumental task of complete national mapping of the 1:24,000 scale map series (about 55,000 maps) in the early 1990's. USGS would often set survey monuments to help "control" the map. Maps are produced from aeronautical photos mosaiced together. In order to provide accurate location, orientation, scale and elevation to a flat map of a curved surface, it is required to have numerous points that can be identified on the photographs for which the coordinates/elevations are well known. The marks set by USGS were a vital part of this operation. In the days when mapping surveys were conducted primarily by line-of-site methods, these marks helped save money by helping to ensure a network that cartographers could rely on for mapping update procedures. With the rapid developments in surveying and mapping technology, especially GPS, USGS sees little need to setting new marks or maintaining the old networks. Unfortunately the data for tens of thousands of these marks set by USGS were never submitted to NGS for inclusion in the National Spatial Reference System. Due to major reductions in staff and the changing nature of mapping requirements, it is highly unlikely that USGS will ever automate these data.

Edited January 14, 2007 by Z15

[DaveD]

The "TT" was a standard designation used by USGS for transit traverse stations. The designation of this mark would be TT 6P 1933 and the 501 is the elevation to the nearest foot. If you provide a more detailed location of the marks I'll be happy to search the USGS data we have in the NGS archives and post USGS data when I get back to work next week.

[+Ken220]

I have uploaded a picture of the benchmark.

This is located at approximately N34 28.629 W 081 31.180 on the Maybinton Road, S-44-45, in Union County, SC. The coordinates are approximate as I haven't been back to the site since October. This would put the benchmark about 5.5 miles ESE of Whitmire, SC.

 

I checked NGS for TT6P and found nothing. Nothing fits distance-wise either. I would guess that the age of this benchmark is probably why it is not listed. The US Forest Service bought this land during the depression. Nothing remains of the house but some bricks used in the foundation. There was a spring used by the house for its water supply. It is known as Jews Harp Spring. It was made in 1858. There is a geocache hidden near the spring.

[+Ken220]

I have uploaded a picture of the benchmark.

This is located at approximately N34 28.629 W 081 31.180 on the Maybinton Road, S-44-45, in Union County, SC. The coordinates are approximate as I haven't been back to the site since October. This would put the benchmark about 5.5 miles ESE of Whitmire, SC.

 

I checked NGS for TT6P and found nothing. Nothing fits distance-wise either. I would guess that the age of this benchmark is probably why it is not listed. The US Forest Service bought this land during the depression. Nothing remains of the house but some bricks used in the foundation. There was a spring used by the house for its water supply. It is known as Jews Harp Spring. It was made in 1858. There is a geocache hidden near the spring.

 

I noticed that it's not clear about the house. This benchmark is located at the site of the old Orange Hall Plantation.

[DaveD]

The age of the mark is not why it isn't in the NGS database. The USGS set tens of thousands of survey marks, typically of lower third-order to provide horizontal and vertical control for the national mapping program. USGS automated a small portion of the horizontal work and provided the data to NGS for inclusion in the national reference frame, but only a very small portion of the vertical control has been incorportated into the national network, and that was typically by U.S. Coast & Geodetic/National Geodetic Survey field teams making the appropriate survey connections.

[+PFF]

This is located at approximately N34 28.629 W 081 31.180 on the Maybinton Road, S-44-45, in Union County, SC. The coordinates are approximate as I haven't been back to the site since October. This would put the benchmark about 5.5 miles ESE of Whitmire, SC.

 

Excellent photo!

 

Reformatting to DDMMSS (as used by NGS), the coordinates are N34 28 37.7, W081 31 10.8. The nearest benchmark in the NGS database is 1.3 miles away. It is triangulation station MAWER (EC1723) on the Newberry-Union County line. The next-nearest station is 1.7 miles.

 

Although your disk is not in the NGS database, it is a good find. Please consider logging it on Waymarking.COM under Recovered U.S. Benchmarks. Because your coordinates are approximate, it would be helpful to include a detailed "to reach" description.

 

Best regards,

-Paul-

 

(Confidential for Z15. My theory on the "6 P" is that this was the last benchmark of the day--just before knocking off for supper. The Chief stamped the hour on the disk, like punching a time clock, showing when they quit.)

[Z15]

Just for info sake.

 

Many USGS marks in my area are considered obsolete.

 

The data sheets say something to the effect. Due to methods employed and the improbability of recovery, USGS deems these marks not worthy of further ties.

 

Its says on some the datasheets USGS no longer guarantees Transit Traverse (TT) stations meet 3 rd order specifications.

Edited January 15, 2007 by Z15

[DaveD]

The USGS description reads:

 

"Blairs, 7.0 mi (airline) NW of; 5.5 mi (airline) SE. of Whitmire; 46 ft N. of centerline of county rd. to Blair; at site of burned old brick house (Cudd Mansion); ub ground space that was once foot-walk to house; 6 ft N. and 20 ft E. of pronged chnaberry tree; 8 ft S. and 3 ft E. of large painted elm tree; in concrete post; standard tablet stamped TT 6 P 1934."

 

NAD 27 Position Latitude = 34d 28m 36.73s

Longitude = 81d 31m 11.35s

NGVD 29 elevation = 500.178 ft.

[+jwahl]

FYI From NADCON:

 

NAD 83 datum values: 34 28 37.23529 81 31 10.71954

 

Versus the approx. N34 28 37.7 081 31 10.8 given. That's pretty close considering accuracy of the GPS and given as approximate.

 

The USGS description reads:

 

"Blairs, 7.0 mi (airline) NW of; 5.5 mi (airline) SE. of Whitmire; 46 ft N. of centerline of county rd. to Blair; at site of burned old brick house (Cudd Mansion); ub ground space that was once foot-walk to house; 6 ft N. and 20 ft E. of pronged chnaberry tree; 8 ft S. and 3 ft E. of large painted elm tree; in concrete post; standard tablet stamped TT 6 P 1934."

 

NAD 27 Position Latitude = 34d 28m 36.73s

Longitude = 81d 31m 11.35s

NGVD 29 elevation = 500.178 ft.