Erased benchmarks?

[AZcachemeister]

A few years ago, the I-10 overpass at 99th Ave, in Phoenix, was part of a freeway upgrade during the construction of the 'LOOP 101' interchange construction. The actual overpass of I-10 was not affected, except that new overpasses were constructed for the on and off ramps from the 101 to the I-10, north and south of the existing overpass respectively. Apparently, during that construction, three benchmarks on the original overpass were re-surveyed and given new stampings. Three other benchmarks were also destroyed in the construction, but that is another story.

I have seen plenty of marks where the stampings were 'crossed out' and re-done, but never have I seen a mark that was 'erased' and re-stamped!

 

DV1690

 

DV1688

 

DV1689

 

When on-site, I decided to take pictures of all the disks I was able to locate, and decide later if I actually photographed an 'original' or a 'replacement'. After looking at the photos, I made my conclusions.

[+shorbird]

ADOT saved your tax dollars through recycling.

[Z15]

I recall once the NGS advisor asked me go file off a mark on a bridge abutment because the concrete foreman placed the wrong disk when they poured the new concrete abutment.

 

He gave them a new survey disk to use but in ignorance of surveying thought to save the mark he needed to reuse the old one. The project was contractor surveyed but their surveyor was laid off before the job was completed and we had to finish the work on the BM.

Edited May 25, 2007 by Z15

[monkeykat]

Here's a disk I came across last weekend, that seems to clearly have another stamping below it. Is this somewhat common? First one I've Seen.

 

OF2415 Restamped?

 

[CallawayMT]

It was pretty common early in the 20th century for the U.S.G.S. pipe caps to be re-leveled and adjusted with a new elevation re-stamped right on the cap.

 

 

CallawayMT

[Papa-Bear-NYC]

KU1431 "C 339" is a really interesting case.

 

First let me mention that this was part of a series of bench marks run out in Manhattan in 1952. A good number are still around although some are missing due to the usual causes in a Great Metropolitan Area. Here's a couple whose pictures came out pretty well for comparison:

 

KU1433 "B 339" and KU1438 "K 339"

 

More or less run-of-the mill 1950s era disks.

 

Now back to "C 339". Here's the picture and a closeup:

KU1431 "C 339"

 

Wow! Where did that come from? And what's with the "M" on the bottom?

 

After a bit of research, I discovered this mark (on the granite base course of the Metropolitan Museum) was actually a mark set in 1909 by the City of New York in the first city wide survey done after the 5 boroughs were consolidated. It was #859 of the 1909 survey. Here's another typical mark from that series, #387, set in Brooklyn an the Grand Army Plaza at the Entrance to Prospect Park:

 

 

Notice the B and the M with the dot in the middle. (This one is not actually an NGS map but it's accross the street from KU1296 "S 347".)

 

It looks like the 1952 crew, when they got to the Met and were supposed to put in another disk for "C 339", got lazy when they found the old 1909 copper plug, and just stamped the new designation on the old plug, obliterating the "B" but leaving the dot and the "M". Close examination of the closeup shows a remnant of the original "B" under the "C". Actually on a place like the Met, this mark is classier and more authentic looking then a brass CGS disk of 1952 vintage, don't you think?

 

Some of the old 1909 marks did make it into the NGS database. If you find a mark in NYC with a designation of just 3 digits, it may be one of the 1909 marks (and I probably put a note on my GC log mentioning that).

Edited May 27, 2007 by Papa-Bear-NYC

[+PFF]

Sometimes, we do know the story behind an erase or restamp.

 

After setting EZ2882, and two reference marks, and an azimuth mark, the survey party had one more chore to do. From the original data sheet:

 

OFFICE NOTE--DUE TO THE PERSISTENT REQUEST OF THE LAND OWNER, THIS STATION WAS RENAMED AND RESTAMPED FROM HUNTER TO HUNT.

 

On all four disks, the "ER" was removed.

 

[Z15]

Back in 1976 (bicentennial year) we had one clever guy who stamped 1776 on a reset mark. Its still our there but I can't recall exactly where. Maybe someone will find it someday. We noticed this when we went in to do the leveling some weeks later and did not have any dies to correct it.

 

Here another documented change

SG0164 STATION RECOVERY (1940)

SG0164

SG0164'RECOVERY NOTE BY COAST AND GEODETIC SURVEY 1940 (JHS)

SG0164'GAY ECCENTRIC HAS BEEN CHANGED TO GAY 2. THE STATION MARK

SG0164'AND REFERENCE MARKS NO. 0 AND NO. 1 WERE STAMPED GAY, 1939

SG0164'ECC. THE INSCRIPTIONS ON THESE MARKS WERE CHANGED TO GAY

SG0164'2, 1939. THE AZIMUTH MARK WILL BE SIMILARLY CHANGED AT

SG0164'A LATER DATE.

SG0164

SG0164 STATION RECOVERY (1945)

SG0164

SG0164'RECOVERY NOTE BY US GEOLOGICAL SURVEY 1945

SG0164'MR. W.W. WIITALA, A MEMBER OF THE U.S. GEOLOGICAL SURVEY,

SG0164'LOCATED AT THE COLLEGE, WHO IS FAMILIAR WITH THE WORK DONE

SG0164'THERE IN 1939, WAS REQUESTED TO MEASURE THE DISTANCES BETWEEN

SG0164'GAY (MICH. GEOD. SURVEY, 1934) AND GAY 2, 1939.

Edited May 27, 2007 by Z15