Daily Kennebec journal. [microfilm reel] (Augusta, Me.) 1870-1975, 1912-12-30
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GREAT DAM AT kEOKUk.
Squeezing Immense Power from Mis-.
sIssippi - Remarkable Engineering
Work.

Across the Mississippi River at Keo-
kuk, Ia, men are building the might
est power dam in the world Inn
mense structures are going up there
In the heart of the continent that will
dam up Americas greatest river.
structures whose size are in keeping
with the rivers immensely, structures
whose dimensions have not an equal in
the whole world.
The first requisite in the seeking to
get power from any river is to find
place somewhere along it's length
where it makes a comparatively steep
fail in a short distance of travel. The
second is to erect a dam at the foot of
the fall, stanch enough to hold up the
waters and concentrate the fall of the
river to one place at the side of the
dam. The third must be to put up a
power house of suitable design to util-
ize the power from the fall of the wa
ter. and the fourth and last requisite,
if the river be navigable. is to provide
a lock to let boats past the dam.
The first requirement. that of hav-
ing steep fall to the river, is satisfied
in this Mississippi Valley development
by the Des Moines rapids in the Mis-
sissippi. which extends for twelve
miles. Not very big fall to be stretch
ed out over twelve miles you think,
twenty three feet in those twelve
miles. Not a very big fall you think.
but when you stop to consider that if
the drowsy Mississippi falls one lone
solitary inch for any other mile of its
length it is lucky, then this twenty
three feet to twelve miles looms up
larger Then too the Mississippi is
standard gage railroad tracks side by
side for the use of construction trains.
1t is not one solid wall, but is com
posed of a series of close set arches,
119 in all, something on the order of q
concrete bridge, only the supporting
piers are closer together. The reason
the dam was made IN this way was
that when too much water accumulate
ed above it's walls for the use of the
power house the surplus could be per-
mitted to slide through the dam by
opening the steel gates that will fill the
gaps between the piers.
Then, too the Government specified
| that such construction be made from
| considerations having to do with min
imum flow of water in the river be-
low the dam.
| something around a mile wide at keo-
| kuk, and when you get stream for
| a mile wide to fall twenty three feet
there is going to be some power result
| ing. Moreover, the Des Moines rapids
are bounded On both sides by steep
| hills, which is very material factor
when dam is placed at the foot of a
falls, and start out to figure the
amount of ground the resulting lake
Will overflow. Having a line of hills
| close on each side of course will limit
materially the amount overlooked.
| Nowhere else along the whole length
of the Mississippi is there so steep "a
| fall in so short a distance or a fall SO
we'll confined between steep hills.
The second step mentioned in the
| process of getting power from the riv-
| er was to dam up the stream and con-
| centrate the fall made over the entire
| length of the rapids to one place,
where the waters could be run through
a power house and their energy
squeezed out. This necessary dam the
builders of the Keokuk project have
now practically finished. For seven
Fights of mile it stretches out oveI
the broad bosom of the Mississippi
from a firm anchorage on the Illinois
shore. 1t is fifty-two feet high and
| wide enough on top to support three
The general type of agent to do the
direct squeezing of the power from thu
Mississippi is the Francis turbine LIE
us go back a little and consider thu
different agents used in other develop
ments. in days gone by: The frs
means used to get power from fall:
was the old paddIewheel. The water
either went over or under it, and |
was known as the "overshot" or slin-
dershot' wheel accordingly This typ
of wheel has been used since time i'm
memorial Its efficiency is very low
TIL. s nrincinle of the turbine mex