----- Original Message -----
From: "Peter Claughton" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Friday, April 04, 2003 10:19 PM
Subject: Re: Pumping


> >>From what depth can a waterwheel driven set of Cornish pitwork pump
from?
>
> Rick,
>
> The question is something akin to the question 'how long is a piece of
> string' as there are some many variables to be considered.
>
> Much depends on the amount of water the mine is making, which might be a
> factor of amount of ground developed at a particular depth; add to that
the
> amount, and head, of water available at surface to provide the power
source.
> A relatively small mine in the south-west of England, like Bampfylde at
> North Molton which pumped to the 112 fathom level in the third quarter of
> the 19th century, could manage quite well with water power alone whilst
> other, much shallower, mines were reliant on steam power. Whereas, I'm
sure
> the Lady Isabella wheel, at Foxdale on the Isle of Man, put in a sterling
> performance in terms of the quantity of water it lifted.
>
> One limitation on the typical 'Cornish' arrangement, of a suction lift
> bottom 'bucket' lift and a series of forcing pumps feeding a rising main
to
> surface, was the ability of the material available to withstand the
pressure
> of the accumulated water. I would suggest that the materials available
> through advances in iron technology in the late 18th century, when Cornish
> copper mining was attaining greater working depths, made the use of
forcing
> pumps possible in larger, i.e. deeper, continuous lifts. Prior to the
> availability of cast iron rising mains, pumping was limited by the
strength
> of the wooden barrels used in suction lift pumps - requiring a number of
> short staged lifts, sometimes called 'shamelling' in reference to the much
> earlier practice of baling water from one level to another.
>
> As to where the mechanised forcing pump was first used as the main lifting
> pump is open to debate but, given the increasing depth of Cornish mines in
> the late 18th century, they are in with a chance. Mechanised, i.e. water
or
> steam powered, is the key because manually operated forcing pumps were
used
> in mid Wales and Devon for short lifts at a much earlier date.
>
> Peter
>
> ______________________________________________
>
> Peter Claughton, Blaenpant Morfil, Rosebush, Clynderwen,
> Pembrokeshire, Wales  SA66 7RE.
> Tel. 01437 532578; Fax. 01437 532921; Mobile 07831 427599
>
> University of Exeter - School of Historical, Political and Sociological
Studies
> (Centre for South Western Historical Studies)
> E-mail:  [log in to unmask]
>
> Co-owner - mining-history e-mail discussion list.
> See http://www.jiscmail.ac.uk/files/mining-history/  for details.
>
> Mining History Pages - http://www.exeter.ac.uk/~pfclaugh/mhinf/
>
> _____________________________________________