I've followed correspondence on this matter with some interest... and
a lot of technical ignorance, I'm afraid.
However I believe William Hedley (1779–1843), of "Puffing Billy" fame,
"took" the Callerton colliery, near Wylam, in 1826 and there developed
a pumping engine which used both ends of the beam. I think it drove a
second (or even third) beam, each end of which worked a water pump.
The result, anyway, was that it pumped water up on both strokes of the
engine. I have read that this system was widely adopted in the north
east coalfields.
Though I think I appreciate Hedley's importance in railway history, in
particular, my own interest in him is more as a coal owner than as an
engineer. For he also owned Crowtrees Colliery, near Coxhoe, Durham,
at that time, and had interests in the Clarence Railway. These are in
my immediate local area of interest.
I'm not really up on the engineering aspects. However I'd be
interested to know how his invention relates to the matters being
discussed in this thread. (I'd also like to know whether he used it
at Crowtrees – though I suspect he didn't.)
Mike
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On 1 Jul 2008, at 20:00, Iain Wright wrote:
> The pumping stroke, using Cornish pumps (not engines!) was always the
> downstroke as it operates a ram in a piston which forces the water
> to a
> cistern on the next level of pumps. It was also more efficient as it
> used
> the weight of the descending pump column (and gravity) to shift the
> water.
> Most of the waterwheel powered pumps of the 19C used Cornish pumps
> in the
> shaft. Lift or bucket pumps are highly inefficient as they can only
> take
> water up to the limit of gravitation, like a village lever pump,
> about 30-40
> ft.
>
> Iain
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