John:
herewith the odd thought.
>1. TOOLS:
>
>
>brace. The whole drill is too short to have drilled more than 8 inches or so,
>which makes one wonder how they drilled the 4-foot-long holes of
>about the same
>diameter that one can still see in the face.
With hand tools it is often better to start a hole with a short drill
rod while you are collaring in since it gives much better control
until the hole is well established.
>
>2. MINING TECHNIQUES:
>
>
>The mining method seems to have been to find the joints, which dip at about 70
>degrees, and wedge the blocks apart by hand. At the end of a "run", when they
>had to cut across unbroken beds, they would drill these approx. 5/8 inch diam
>holes up to 4 feet long, and presumably blast. But I can recall no blast
>damage to the surrounding rock such as you often see on modern jobs
>- does this
>mean they were using Black Powder??
Black powder might still leave stains, it may be that they were using
wedges in some holes for splitting - or they could be firing a
presplit round to stop damage going out into the surrounding rock.
If the rock was that soft it would probably be easier to cut it to
shape on site where they would have the dimensions that they need
for the piece to go into.
>
>4. QUESTION:
>
>Is there anything I have said above about the "auger" (what would
>it have been
>used for originally, anyway?) or the mining method that would allow anyone to
>guess at the age of the operation. Texas Parks and Wildlife would
>sure like to
>know!
>
>Thanks for any thoughts
>
>John
Sorry can't help here
Dave
--
David A. Summers
Curators' Professor of Mining Engineering
Adjunct Professor of Nuclear Engineering
Director
Rock Mechanics and Explosives Research Center
University of Missouri-Rolla,
Rolla, MO 65409-0810
"fools talk, wise men listen." (a variant of Prov 12:23)
phone: (573) 341 4314
FAX: (573) 341 4368
related web pages
A growing selection of Dr. Summers' papers are being put on the Web
and can be accessed through the Bibliography
http://www.umr.edu/~rockmech/faculty/biography.html
Rock Mechanics http://www.umr.edu/~rockmech/
Waterjet Lab: http://www.umr.edu/~waterjet/
UMR Stonehenge: http://www.umr.edu/~stonehen/
Personal: http://www.umr.edu/~rockmech/data/Summers.html
Mining Eng. http://www.umr.edu/~mining/
Waterjet Assoc http://www.wjta.org/
International Waterjet Society: http://www.iw.uni-hannover.de/iswjt/
Next American Waterjet conference: http://www.wjta.org/conference.htm
Next International Waterjet Conference (Provence, 2002)
http://www.bhrgroup.co.uk/confsite/jt02home.htm
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