NGS Surveyor Posted December 8, 2010 Posted December 8, 2010 An interesting article about a Coast & Geodetic Survey triangulation crew was just published in the “American Surveyor” magazine, see: http://www.amerisurv.com/PDF/TheAmericanSu...S98_Vol7No9.pdf The article has some great color photos from the period and discusses conscientious objectors service in the C&GS. Of special interest is the photo showing the summit of Wheeler Peak and the remains of the stone wall built during the C&GS’ Transcontinental Triangulation along the 39th parallel during the 1870’s and 1880’s. Some of the stone walls remain to this day. There are also articles on the C&GS in WWII on the NOAA History www site at: http://www.history.noaa.gov/search.html And search for “World War II”. GeorgeL NGS Quote
+pgrig Posted December 10, 2010 Posted December 10, 2010 Does anyone know if (and how) the wartime equivalent of the Datasheets were secured during the war? I am always amazed that the precise coordinates of almost all of the fire control instruments that directed the Coast Artillery for Boston Harbor were available as USCGS/Corps of Engineers marks--also many of the gun batteries themselves. Could a local surveyor readily access these (as we do today) in 1940-1946? -Paul Quote
Bill93 Posted December 10, 2010 Posted December 10, 2010 I think that since the records were on paper, ALL users had to write to C&GS to obtain copies. That would provide a measure of control over who accessed them and which ones were handed out. Obviously they weren't on the internet until the last couple decades. Quote
monkeykat Posted December 10, 2010 Posted December 10, 2010 thanks for the interesting lunchtime read. In one of the photos, the Safford AZ camp, it looks like they are camped out next to a horse racing track. I looked around a little, and did see that Safford AZ does have a quarterhorse track, but didn't find any info on the date it was created. It is located on what is called the Graham County fairgrounds, which seems like a likely place to have a group camp out while they do their survey. Quote
68-eldo Posted December 11, 2010 Posted December 11, 2010 My first real job was Fire Control Technician (Gunnery) for the Navy. So I am not at all surprised that the locations of the fire control towers and gun batteries were very precisely surveyed as this had a lot to do with the accuracy of guns. The actual Lat/Lon was immaterial, the distance and bearings (azimuths) between the various components was the information needed to compute parallax, both vertical and horizontal. Without parallax your guns will always miss the target by the distance between the fire control tower and the battery. Quote
+pgrig Posted December 11, 2010 Posted December 11, 2010 The harbor defenses of Boston, Portsmouth, and Portland seem to have been heavily seeded with geodetic marks, compared to those in other areas of the country. Almost all of the WW2-era fire control structures had disks set in their roofs that marked the L/L of their primary observing instruments (which were stacked up on top of each other on multiple levels of the towers). In the 1938-1941 time period, many of the locales that had been picked for fire control structures had "Location" disks surveyed, and numerous minor stations were also set, as the surveys moved forward. All WW2-era gun batteries had USE grid system coordinates established for their Directing Points (DPs), which were usually the pintle centers (fulcrums) of the mounts of their No. 1 guns (the ones on the right as you looked seaward). Displacement for other guns in the battery could then be computed from these DPs. In older, pre-war batteries, the DP was often a separately surveyed point, located 30-50 ft. out in front of the battery. Quote
+shorbird Posted December 12, 2010 Posted December 12, 2010 Also along the coast of RI many benchmarks were actually pintles in batteries. Thanks for the details about that. Quote
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