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t8r

hole cutting device 1947

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a4256533-5412-4999-8189-14f463e80aea.jpg

 

It's a lot of fun benchmarking around here (83647). There are a ton of old BMs in the area, Many of which have not been logged in 50 or more years. Yesterday the weather was cold and windy, so I drove out to NV0971 (1947) and log it. That gave me a chance to start exploring the old glenns ferry-castleford road (not on current maps). The settings for the station and RMs are set in basalt boulders that were brought in from nearby and buried for the purpose. The practice of moving boulders into sandy areas for BMs was commonly done in the area.

 

I can't get Groundspeak's link thing to work :unsure: so here is the URL.

http://www.geocaching.com/mark/details.aspx?PID=NV0971

 

My question involves the cutting tools used for making the hole for plugging the disc into. I just assumed (there i go assuming again) that an apprentice with a star drill and hammer would be the mechanism involved. But look at the nice circle cut into that rock. Looks like some kind of hole saw that did not need a pilot hole.

What was it they were using? Additionally, rock outcrops were often used for settings. What did they use for power for turning a drill? Electric generator, gas powered drill, or human power?

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That is unusual and unexpected!

 

I would think the holes for monumenting marks in 1947 would have been made by a star-drill hammered and turned by a person or persons.

 

That circle is just too weird, especially if the mark appears unvisited for 50 or more years. Is this an isolated item, or are there several in the area? I suppose a similar mark could be made by spinning a thin-walled pipe in the same spot on the rock, but why?

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That's the only one I've seen. I will be checking more marks in the area and will be watching for more.

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Good find!

 

I'm pretty sure your image is like a benchmarking crop circle. Have there been any reports of small, weird flying disks hovering over likely-looking boulders? And are you sure about those stories of NGS staff "bringing in" the boulders from elsewhere? Has anyone ever seen them lugging boulders around? I rest my case...

-Paul

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OK, so there goes my crop circle theory... (beautiful old photo, by the way).

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I guess what i was really looking for was: What were the standard tools for drilling holes in settings in 1947. Someone here knows. No one is leaving until i find out. :o

If a diamond cutter was in the tool kit, that would explain why The circle was there. Possible scenario: Sheep herder rides up, dismounts and gets in a conversation with the head man on the job (the head man happens to be able to speak Basque), The conversation leads to a discussion of, how the hole was drilled in the rock. Of course, the duty hole driller showed the sheepherder how it worked. This certainly would throw reasonable doubt on Paul's theory about the crop/boulder circles.

I wondered what the monumenters were using to power the drills in those days. Gas powered generator, gas powered drill, or extension cord from hotel.

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Ever heard of a hand drill?

StanYank1446XDrill.jpg

 

My grandpa had a few.

I got one or 2.

 

 

Do I detect a note of sarcasm there. Now I'm trying to picture someone out there in January 1947 attempting to drill a 3/4 inch hole 2 or 3 inches into a chunk of basalt with that infernal tool in the picture!

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Holes were usually drilled with a star drill or various somewhat portable gas driven drills if you could afford one and probably after 1920 or so.

 

My guess is that someone decided to 'try' a circular diamond bit and it wasn't working very well so they abandoned the effort. If they had a gas powered drill it may have broken down at that point.

 

It could also have been that it wore out quickly at the depth shown. Other problems I can imagine are that once you had a circle drilled a half inch deep or so it would seem to me it would bind against the rock. And even if you were successful in going 3 inches deep, you would still have to chisel out the center material.

 

Surveyors have had various small gas driven drills for quite a few years if you did this a lot. I used a fairly large one about 30 years ago I only remember the name "WACKER" on it which may have been a manufacturer. It would drill a really nice 1.25" hole very quickly and looked like the proverbial jack hammer. It weighed about 90 lbs. and would be about all you could carry over your shoulder. Sandstone would practically vaporize under it.

 

Another brand commonly used was called a Cobra and the name Pionjar rings a bell too.

 

Cobra Drill

 

Modern Model

 

 

Here is one that isn't working that well compared to the Cobra, but looks like it is drilling with a cylindrical bit

 

 

I have seen drill holes all over the place in Rhode Island that are used as monuments and property corners. These had to have been mechanically drilled with some gas driven device. I suspect that practice is true thoughout New England.

 

Except for the one project where we had the "Wacker" mentioned above most of the disks I set in rock were set in a hole drilled with much arduous labor with a star drill and a 4 or 5 lb. hammer.

 

- jlw

Edited by jwahl

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Ever heard of a hand drill?

snip

 

My grandpa had a few.

I got one or 2.

 

 

Do I detect a note of sarcasm there. Now I'm trying to picture someone out there in January 1947 attempting to drill a 3/4 inch hole 2 or 3 inches into a chunk of basalt with that infernal tool in the picture!

 

Nope not from me.

Just the way I talk.

 

I have seen and used these hammer type hand drills with a diamond bit and it cuts faster than you think.

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I used power drills to set disks in the late 1970’s (Wacker and Cobra models). I also checked USC&GS Special Publication No. 247 which was originally written in 1950 and updated in 1959. I did a digital search and the 1959 version does not mention power drills at all. My next step was to email a retired USC&GS employee who hired-on in the 1950’s. I asked him when the first power drills were used by the USC&GS and his answer is “1959-60, the Cobra Copco, in Plainfield, NJ, Party 607 (later G-19), Chief of party LT V.B. Miller. They also came with a space bit which made them useful in hard digging for anchor holes” (for Bilby Towers). As a side note, I was chief of Party G-19 from 1978 to 1980.

 

GeorgeL

NGS

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Thanks for all the help. That establishes that the holes for mounting were never created with any kind of a hole saw. Likely that someone was playing around with a diamond or carborundum hole maker when the station was "OCCUPIED TO ESTABLISH ETVA ELEVATION" in 1975 or at some other time.

So what the heck does ETVA stand for?

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ETVA guess would be "Electronic Traverse Vertical Angle" which might be their name for trigonometric levelling with EDM.

 

- jlw

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ET might also stand for Electrotape a brand on EDM

 

EDM (Electrotape)

 

Catalogue number:

1996.0195.01

 

Inscriptions:

"ELECTROTAPE MODEL DM-20 CUBIC CORPORATION SAN DIEGO CALIF. 92123" and "MODEL DM-20 SERIAL No. 402 U.S. PAT. No. 3,078,460"

 

Dimensions:

16 inches high, 15.25 inches wide, 12 inches deep

 

Discussion:

 

The Electrotape DM-20 is a transistorized microwave EDM. The first commercial unit, serial number 151, was unveiled in 1961. It yielded centimeter accuracy over distances from 100 meters to 40 kilometers, and in all weather conditions, day and night. Each unit cost about $6,000 and weighs about 25 pounds. For use, two units are needed, one to send the signal and the other to receive it. The DM-20 at the Smithsonian, serial number 402, was probably made in the early 1960s. It remained in production for about 20 years.

 

Cubic's involvement with EDMs began in June 1958 when the United States Army Engineer Research and Development Laboratory (ERDL) asked them to develop a domestic equivalent of the Tellurometer MRA/1. The first Micro-Dist, as the instrument was then known, was delivered early the next year. Like the Tellurometer, Micro-Dist used data compression by means of modulation side-band folding. With Micro-Dist, however, the two units were interchangeable. Other differences pertained to Cubic's diplexing system, receiver, and manner of digital readout. Micro-Dist operated at 10 Gigahertz. Cubic claimed an accuracy of 1:150,000 ± 2 inches. Micro-Dist was advertised as early as March 1959. In 1960, owing to a conflict with Tellurometer's Micro-Distancer, Micro-Dist was renamed Electrotape.

 

Another ERDL contract for a "miniaturized" instrument (this one for $55,000 and signed in 1959) led to the solid state DM-20, which was to be a domestic equivalent of the Tellurometer MRA/2. The DM-20 was protected, in part, by patent #3,078,460 for "Electronic Surveying System" granted on February 19, 1963, to Robert V. Werner and Eddy Hose, and assigned to Cubic Corp. When aspects of the DM-20 appeared to infringe patents owned by the Union of South Africa and licensed to Tellurometer, Cubic and South Africa decided to cross-license their designs.

 

Ref: Cubic, Instruction Manual for Model DM-20 Electrotape.

 

Cubic, Cubic Model DM-20 Electrotape.

Edited by Z15

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