+Vines Posted January 10, 2008 Posted January 10, 2008 I looking for this benchmark and I think I've found it. It appears to be a metal rod that is bent over so it's more horizontal than vertical. It's in the lawn of the church that is described in the data sheet. I'll post a picture later. Does anyone have any photos that could upload to compare to? Quote
+Ernmark Posted January 10, 2008 Posted January 10, 2008 (edited) Here's one: KW3227 This is an NGS type of BM which began showing up in the 80's.. There are also examples of benchmark disks mounted to rods as well... Edited January 10, 2008 by Ernmark Quote
NGS Surveyor Posted January 10, 2008 Posted January 10, 2008 For a cross-sectional view of an NGS stainless steel rod mark see the 1978 NGS publication, "GEODETIC BENCH MARKS" at: http://www.ngs.noaa.gov/PUBS_LIB/GeodeticBMs/#figure04 The rod you found MAY have been hit by some landscaping equipment. I have a rod in my office from Alaska that is bent about 45 degrees that I believe was hit by a snow plow. GeorgeL NGS Quote
+Vines Posted January 10, 2008 Author Posted January 10, 2008 (edited) This is where I saw the piece of bent iron. This is the description for the BM. Doesn't that location appaer to be correct? DESCRIBED BY NATIONAL GEODETIC SURVEY 1980 IN BIRMINGHAM. IN BIRMINGHAM, • AT THE INTERSECTION OF 22ND STREET AND 3RD AVENUE NORTH • SET ON THE SOUTHWEST SIDE OF ST PAULS CATHEDRAL IN THE LAWN BETWEEN THE SIDEWALKS FOR THE SOUTHWEST ENTRANCE TO THE CATHEDRAL AND THE SOUTHWEST ENTRANCE TO THE BASEMENT OF THE CATHEDRAL • 4.78 METERS (15.7 FEET) NORTHEAST OF THE NORTH CORNER OF THE PARISH AND OFFICE BUILDING • 4.6 METERS (15.1 FEET) SOUTHEAST OF THE SOUTHEAST EDGE OF THE SIDEWALK OF THE SOUTHWEST ENTRANCE TO THE CATHEDRAL, • 2.44 METERS (8 FEET) NORTHWEST OF THE NORTHWEST EDGE OF THE SIDEWALK OF THE SOUTHWEST ENTRANCE TO THE BASEMENT • 2.12 METERS (7.0 FEET) NORTHEAST OF THE NORTHEAST EDGE OF THE SIDEWALK AROUND THE PARISH AND OFFICE BUILDING. • THE MARK IS 0.1 M BELOW GROUND. Edited January 10, 2008 by Lane Vines Quote
+Black Dog Trackers Posted January 10, 2008 Posted January 10, 2008 (edited) The rod's metal should be smooth and basically silvery color, without any rust or other oxidation corrosion. The end of the rod should be rounded like a small hemisphere. Rods are almost never out of the ground and bent. There was a picture posted within the last couple weeks of a rod that was apparently pulled out and bent but that was apparently done by heavy highway equipment. In the churchyard setting it is unlikely that equipment able to pull out and bend a geodetic rod would've been used. I'm just guessing here, without a picture, there is a vague possibility that, if your measurements to the metal in question match those in the datasheet, but the metal is not the typical geodetic rod metal, the metal you see may be a sort of witness post for the lid of the rod's enclosure 0.1 M below ground. I don't suggest messing with the rod, but sticking a probe into the ground next to it might indicate the presence of the lid of the rod's enclosure underground. The hinged lid with its rim should be about 4 inches in diameter. Edited January 10, 2008 by Black Dog Trackers Quote
+Harry Dolphin Posted January 11, 2008 Posted January 11, 2008 Ah. Hmmm... The arrow does point to the intersection, but, if the map's oriented to the north, that's the northeast side of the cathedral, not the southwest? Assuming the smaller building to the southwest to be the parish and office building, I think you're on the wrong side of the cathedral... Quote
+Vines Posted January 11, 2008 Author Posted January 11, 2008 Ah. Hmmm... The arrow does point to the intersection, but, if the map's oriented to the north, that's the northeast side of the cathedral, not the southwest? Assuming the smaller building to the southwest to be the parish and office building, I think you're on the wrong side of the cathedral... Thanks Harry! I see it your way. Based on the other's comments too I'm sure that wasn't the benchmark. I need to get permission to get in passed the fence to look. Quote
Z15 Posted January 13, 2008 Posted January 13, 2008 this is the key location info... 4.78 METERS (15.7 FEET) NORTHEAST OF THE NORTH CORNER OF THE PARISH AND OFFICE BUILDING Quote
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