StripeMark Posted August 15, 2006 Share Posted August 15, 2006 http://www.ngs.noaa.gov/cgi-bin/ds_mark.prl?PidBox=JE0245 What exactly on this structure would be the benchmark? The datasheet says that the marker type is a azimuth mark disc and it states that there is a stamping. But the station description doesn't say where the disc would be located on the structure. I found this "concrete pedestal" as described, but there was no survey marker found, or evidence that there was ever one there. All it was is a concrete post about 1.5 feet across and about 5 feet high with 3 bolts in a triangle formation protruding out the top. Any idea what these were used for? Has anyone ever located a survey marker on these structures? Thanks! Quote Link to comment
mloser Posted August 15, 2006 Share Posted August 15, 2006 A Tribrach, I learned from Wikipedia, is either an instrument attachment plate containing three thumbscrews , meaning a place to attach a theodolite, or a type of meter used in poetry. I vote for the attachment plate definition, and therefore think this is a monument ready made for a surveying instrument to be mounted on it and used. I found a similar one at SUSQUEHANNOCK. Quote Link to comment
wister6813 Posted August 16, 2006 Share Posted August 16, 2006 I have looked for a couple of pedestals without success. They are found around central Missouri in the vicinity of the former Minuteman missile silos. I presume they were used to mount a theodolite or similar instrument used to locate the silo. It appears the silo was located to the northeast of KE0245. I’ve noticed that each of the former silo sites appear to have six monuments related to the launcher. The pedestals were monumented by the DOD, while the others were monumented by the CGS. The pedestals include B 1 and B 2 in the designation name. There is a gentleman that is retired Air Force that seeks out former and current Air Force facilities. He posts his trip reports on the internet. He includes a couple of Theodolite Posts in conjunction with former missile silos. Photos may be viewed at www.airforcebase.net/trips/solo/solo.html and www.airforcebase.net/trips/md/md.html. The second URL has a photo link towards the bottom of the page of the top of a post. This is what I image the concrete pedestal will look like if I find one. Is this close? Bob Quote Link to comment
StripeMark Posted August 16, 2006 Author Share Posted August 16, 2006 check out these pics that I took: http://www.geocaching.com/mark/details.aspx?PID=je0245 So is there a actual survey marker disc on these???? It doesn't sound like it according to the text description. So it would be a found? not found? Should I report it to NGS as a found? not found? .....or just e-mail Deb and see what she has to say about it? Quote Link to comment
foxtrot_xray Posted August 16, 2006 Share Posted August 16, 2006 check out these pics that I took: http://www.geocaching.com/mark/details.aspx?PID=je0245 So is there a actual survey marker disc on these???? It doesn't sound like it according to the text description. So it would be a found? not found? Should I report it to NGS as a found? not found? .....or just e-mail Deb and see what she has to say about it? IMHO, I'd say you found it. The desc says it's a concrete with a tribrach. In a previous post, a tribrach was a lpate with three screws. Looking at your last picture, I see... a plate. With three screws. I'm curious about the following two lines from the datasheet: JE0245_MARKER: DZ = AZIMUTH MARK DISK JE0245_STAMPING: M 7 B 1 Only because it's not a disk, and there's no stamping on it? However, despite that, I'd say you founf it, acording to the description. Me. Quote Link to comment
+Klemmer Posted August 16, 2006 Share Posted August 16, 2006 I would agree. I believe the last sentance means the actual survey point is the middle of the three bolts (screws). No need for an actual disc or mark point with a slick setup like this! I saw a similar two posts on a US Army Corps of Engineers dam (one on each end), but they were not in the NGS database. Quote Link to comment
+Elde Posted August 17, 2006 Share Posted August 17, 2006 I’ve noticed that each of the former silo sites appear to have six monuments related to the launcher. The pedestals were monumented by the DOD, while the others were monumented by the CGS. The pedestals include B 1 and B 2 in the designation name. Depending on how close they are to the silo - they may have been used during missile loading to ensure accurate alignment of the bird in the silo. The bird has to know where 'North' is, as the launch control system sends the launch bearing in relation to North - any error in aligment is multiplied manyfold across the total flight distance. (A little trig will show how large an error as little as 1 arc minute will grow.) Another thought is that they may have been used to measure the alignment of the transporter/loader to ensure that it was a) vertical, aligned to the silo center, and c) aligned rotationally to the silo systems. I'll be seeing a buddy of mine who was a Minuteman silo crewman and see if he can remember what they were used for. (We did things differently with the SLBM's - since our silos were 'mobile'. ) Quote Link to comment
+BuckBrooke Posted August 18, 2006 Share Posted August 18, 2006 A number of the stations used for alignment/elevation for the Nike/Zeus (1950s/early 1960s) missile sites made it into the database; they're on my list of disks to make a website about. I'll add these Minuteman ones to the list. The trick is finding a webpage with the coordinates of the Minuteman sites. I'll look into that. Quote Link to comment
wister6813 Posted August 21, 2006 Share Posted August 21, 2006 If you can use a ESRI shape file the Missouri silos and launch control facilities can be found on the Missouri Spatial Data Information System (MSDIS) web page at this location. Since they were decommissioned due to the SALT II treaty they are tracked by MoDNR as a Formally Used Defense Site. Quote Link to comment
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