Many thanks Roy, it's all very interesting and useful - I have this and all other responses on file for forthcoming use.
Andy
On Wednesday, 5 July 2017, 16:16, Roy Fellows <[log in to unmask]> wrote:
Hello people
Being away until Monday and being at NAMHO previous weekend, things to do etc have prevented me adding to this thread sooner, apologies.
Pumping and pitwork is one of my favourite subjects.
First I would like to mention some notable publications which cover the subject. We all know about Bradford Barton, however there is also "On Pumps used in Mines" by John Taylor 1829, Colins Philips and Darlington 1875, "Cornish Pitwork" by Michell and Letcher 1876
I feel that the word "Plat" is obviously an abbreviation for "Platform" being a bit ambiguous in that it could be applied to the heavy timbers used to support the "Bob", or a section cut out of the side of the shaft itself to house this, or maybe installed in a level off the shaft.
Now "Bob" ( in the underground sense, not engine house) is also ambiguous in that it could refer either to a fend off bob, andgle bob, or balance bob. The first used to support pump rods in a section of the shaft sunk on the underlie of the lode, maybe just set into the shaft side. Angle bob is a little more complicated. Used where there is a change of direction in the power train, it will be subject to a heavier load and would usually be in the form of a "V" with a wrought iron strapping plate across the top of the beams. This would require a more substantial placement.
A balance bob is most complicated and would usually be set into a level being quite a large affair of rocker beam, king post, sometimes a queen post, weight box and iron strapping plate. Probably double the length of a simpler angle bob. A fine surface example is to be seen on surface at Minera, alsbeit a reproduction, not the original. Nice one at Cwm Ciprwth as well.
Now if this wets your appetites there are some photos of the arrangement at Llanrwst Mine which is quite complicated on aditnow website under the mine of that name. You might also want to look under Parc Lead Mine.
https://www.aditnow.co.uk/Mines/Llanrwst-Lead-Mine_2801/
https://www.aditnow.co.uk/Mines/Parc-Lead-Mine_298/
Interesting bob at Temple Mine as well.
https://www.aditnow.co.uk/Mines/Temple-Lead-Mine_4315/
I think it worth mentioning that the thinking on pumping arragements was vastly different between Wales and Cornwall, possibly affected by the vast difference in average shaft depths.
Hope all this of interest.
Kindest regards
Roy
-----Original Message-----
From: mining-history [mailto:[log in to unmask]] On Behalf Of Andy Cuckson
Sent: 02 July 2017 07:00
To: [log in to unmask]
Subject: Bob-plat definition
Dear fellow Listees,
Can anyone give me a comprehensive definition of a bob-plat please?
Best regards,
Andy Cuckson
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