"Donut Hole" Mark Remains: Unusual or Not?

[+pgrig]

Here is a report on the remains of a mark I just visited at Ft. Wetherill near Newport, RI.

 

It occurred to me that I have seen several of these "donut hole" remains (where a vandal has managed to pry up the entire disk except the datum point, including the station-identifying triangle). There are a number like this at Ft. Wetherill, and I found one for station STRONG at Ft. Strong in Boston Harbor.

 

Are these fairly unique to the "Coast Defense Vandal" in New England, or have others seen similar remains? All the disk remains like this that I have seen were set around 1934-1941. Was there perhaps something about the disks used during that time period that made them easy to fracture while leaving behind the tip of the stem?

[kayakbird]

... All the disk remains like this that I have seen were set around 1934-1941. Was there perhaps something about the disks used during that time period that made them easy to fracture while leaving behind the tip of the stem?

 

This is a 1937 COE (USE), one of a series of 'Map Control Points' set in the top of concrete filled 3 in iron pipes which ring the shoreline of Fort Peck Reservoir in northeast Montana. Maybe these were cast with the same style of tang.

 

 

SQ0582 The pipe setting was not disturbed.

 

an intact one 3.5 mi south.

 

 

SQ0563 kayakbird

Edited March 3, 2011 by kayakbird

[+king.hubi]

I have been visting Fort Wetherill some moons ago. Looked to me like a hangout place. Maybe the people who sprayed the walls found also interest in the bench marks. But I think these "Donut Marks" are not so unusual.

 

Here is a nice one set in 1937, MY6361 - WATATICK 2 RESET. If you look closely you can see a chiselled triangle around the donut. Reference mark no 3 is in the same condition.

 

 

And this is MY4937 - POOL HILL. Not really a Donut Mark but it's also broken. But in this case during the setup.

 

01/01/1916 by CGS (SEE DESCRIPTION)

DESCRIBED BY COAST AND GEODETIC SURVEY 1916 STATION IS ON THE HIGHEST PART OF A PROMINENT HILL JUST N OF THE ROCKPORT DEPOT OF THE BOSTON AND MAINE RAILROAD. THE STATION IS MARKED BY A CROSS IN THE SHANK OF A STANDARD STATION MARK, THE PLATE HAVING BEEN BROKEN IN SETTING THE MARK. THE MARK IS SURROUNDED BY A TRIANGLE CUT IN THE ROCK. ...

 

Btw, if I remember correctly, there were a lot of graffities. Have you seen Marilyn on the Wall?

[AZcachemeister]

I have recovered one or two like that here in AZ.

[+pgrig]

OK, so there are lots of others around...! Were these disks cast sort of in two pieces, so that trying to lever them up by the edge caused them to fracture around a ring in the center? Seems odd.

 

[And yes, Ft. Wetherill is the most heavily-tagged Coast Artillery fort I have come across in my two years of working these in New England. It is still a favorite hangout for kids; I saw five of them filming a video at the fort while I was there, with tripod-based video lights and furniture imported as props. :-)

[NGS Surveyor]

Re construction of disks, see Figure 31 in my paper. It shows side views of 5 different disks. The older ones were cast, I believe, in one piece. The newer ones had the stem brazed onto the back of the disk.

Link to paper: http://www.ngs.noaa.gov/web/about_ngs/history/indexhUSCGS.shtml and scroll down to "Bottle, Pots...."

 

GeorgeL

NGS

[+NorthWes]

TU0339 BLOW RM 1, set in 1931, exhibits the same 'donut' pattern you've described. The center remnant contains a portion of the arrow bar (pointing the wrong way, per recovery notes)

 

 

The first geocacher to find the mark felt erosion had caused the disk to disappear. Shorelander's recovery comments from 2009 state the damage is more likely from vandalism than erosion. I have to agree, having seen many disks at shoreline settings where erosion hadn't damaged the disk to this extent at all. And - anyone who's seen Shorelander's exquisite photos from around the Hawaiian Islands of disks in this sort of setting show they hold up quite well in a saltwater environment. Here's an area view of TU0339 BLOW RM 1, looking SSE over the unique setting in a volcanic boulder:

 

Edited March 3, 2011 by NorthWes

[+Jayman11]

Maybe I'm looking too much into it but it almost looks like in that picture of the post remaining that you can see a spot at about 7 oclock where something might have been used to pry it up and off.

 

TU0339 BLOW RM 1, set in 1931, exhibits the same 'donut' pattern you've described. The center remnant contains a portion of the arrow bar (pointing the wrong way, per recovery notes)

 

 

The first geocacher to find the mark felt erosion had caused the disk to disappear. Shorelander's recovery comments from 2009 state the damage is more likely from vandalism than erosion. I have to agree, having seen many disks at shoreline settings where erosion hadn't damaged the disk to this extent at all. And - anyone who's seen Shorelander's exquisite photos from around the Hawaiian Islands of disks in this sort of setting show they hold up quite well in a saltwater environment. Here's an area view of TU0339 BLOW RM 1, looking SSE over the unique setting in a volcanic boulder: