"Broken"- pillar working. The partial working of pillars in fiery
collieries was commenced in the Tyne Collieries below Bridge, in
1795, the first experiment being made by Mr. Thomas Barnes, in the
High Main Seam, in 1795. Before this plan was adopted, only 40% of
the coal could be obtained under a depth of 100 fathoms, 60% being
lost in pillars. After its adoption, 55% was obtained and 45% was
lost (Buddle Evidence before Select Committee of House of Lords 1829).
The process was called "robbing the pillars." Further improvements
were made by Mr Buddle at Percy Main colliery in 1810 by which from
80 - 90% were obtained but an increased quantity of small coals made
(Buddle). During the present time very little coal need, by proper
management, be lost in pillar working No rule can be laid down as to
how pillars should be taken off; so much depending upon situation and
the nature of the roof, and thill, and coal. the principal thing to
be attended to is getting the pillars as quickly off as possible, and
to be very careful in getting all the coal practicable, together with
all timber, so as, by enabling the roof to fall freely, to remove
pressure from adjoining pillars and avoid creep.
"Jud" - a portion of the seam kirved, nicked and ready for blasting,
called also 'vantage, or advantage, also a portion of a pillar in
course of being worked away in in the broken mine."
Quotes from "A glossary of terms used in the Coal Trade of
Northumberland and Durham" by G.C. Greenwell 1888 edition).
>
>Came anyone tell me what a "brokens" was, and what a "jud" was. I come
>across these phrases fairly regularly, but I could do with a decent
>definition.
--
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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