

Taken on 06/23/11
Some nearby machinery, I assume related to the mill buildings.
See
photos on Page 55 for some photos of two mills
along the same river/trail.



On 9/12/11 Scannerman
writes in reference to the top photo above;
"That's not just SOME
machinery, that is THE machine: a waterwheel--the very heart that ran that
factory and the early industrial revolution! I double-checked with Bob Lewis,
who is the chief poobah at Lewis & Clinch in Watertown--one of the few companies
left in the world that works on water wheels--to make sure. To be exact, he
corrected me, it is a Francis-style horizontal double water turbine. It's an
unusual one in that normally double ones have one clockwise and one
counterclockwise wheel to even out the horizontal thrust on the shaft (and
yes--the wheels are attached to the same shaft; the flow direction = the
direction that the water goes through each wheel before "exhausting" through the
wheel's center.)
My diagram [click the diagram below this message] shows one of the two set-ups that this turbine
probably was (top two pix), which also show that the part of the turbine in the
left third of the photo was originally in a housing which was out in the pool of
SOURCE WATER. The housing has a big valve (blue arrows in center pic), over top
of each set of turbine blades--when the valves were opened, the turbine began to
spin. After hitting the blades, the water went OUT through the center of the
wheels (red arrows), and through the tailrace to continue merrily downstream
(more at
https://en.wikipedia.org/wiki/Water_turbine).
The
speed of
the source water isn't a big deal (except to ensure a steady supply of water),
but the difference in HEIGHT between the source water and the tailrace generates
the power. That's why water power needs to have dams to serve as as "artificial
waterfalls".
Another cool bit of trivia: The end of the "draft tube" (or a
simple tunnel), that carries the water away from the turbine must always be
under water to create a huge SIPHON that actually sucks water through the
turbine, multiplying the effect of gravity alone!"
