The Mitchell capital. (Mitchell, Dakota [S.D.]) 1879-1918, 1911-10-19

fert comparable only with rurh
works AZ the Asaouah dam In Egypt
and The Panama Canal. II IL tho
greatest project OF the kind I'M
America.
Between Monttosc and keokuk.
twelve miles. the Mississippi has a
fall of t~wenty-thfce feet. forming
what is known as the Dies Moines
Rapids, the greater part of this fall
being in the lower eight miles. The
river IL In solid limestone and It's
bed Is practically smooth. SO that
there Ii no broken water or surface
disturbance except during very low
water. The river channel itself Is
only navigab.c 1T high water how
ever. and navigation past the rap
ids Is provided for by a government
canal. The river here ! nearly a
mile wide and has Il Cepth OF about
seven feet at mean water.
The dam will raise the water lev
cl about t~hirty-dve feet Ut TIE dam,
%submerging a considerable area c,
fiat and along the banks, and form
ing IL pool about sixty miles in
length. The normal working head
on the hydraulic machinery at the
power house will he thirty-two feet.
but the head may vary from twenty
one feet at high water to thirty-ninc
feet at low water.
May Cost 3 Mn,ions.
The project OF utilizing the vast
power of the rapids dates back TO
1854. 1t was not. however, until
Boston capitalists took hold of the
proposition a few ears ago that the
work actually begun. The plan now
being carried out will cost 6 or { mil
lion dollars. 1t for a concrete
spillway Jam extending i.27S feet
from its east abutment. which abut-
bent is 29O feet long to the east
bank OF the river. 1t will consist OF
a series of l19 arch spans so feet
long. on piers 6 feet thick, forming Q
bridge 20 feet wide on top. Later
each 3O-foot opening will be CLOSED
to the spillwav elevation by IL dam
or weir. The water level will b.
raised above the spillway crest by
steel gates closing each 30-foot OF.
ening.
Power House 100 feet long.
The power house will be built
parallel with the stream and its sub
structure will be practically Il solid
mass OF concrete seventeen hundred
feet long and 1913 feet wide, with
its floor forty-fve fet above the riv-
er bed. In this concrete will be
formed the wheel pits and the con-
duits or passages for tie water To
IL from the wheels. y ooffeldam.
inclosing t%hirty-five acres, now su:-
ounds the site for the power house
which will rest on the solid bed OF
he river. There will be thirty gen.
rators, but the first installation
will consist of fifteen generators.
Each main unit will consist of a o.
500-kilwatt, revolving-field alterna-
tor.
Navigation past the rapids is pro-
vided for at present by a canal and
.ocks on the Iowa side, as the river
channel can be n%avigated only at
high stages of water. These works
were built by the government and
completed in 1887. The canal is
eighl miles long. and is separated
from the river by an earth embank-
ment faced with riprap. 1t has three
locks each of eight feet lift and
provides for vessels having mini
mum draft of six feet. The locks
are 225X7S l-2 feet, with q depth OF
six feet. When the new dan is
built, these rocks, about three miles
apart, will be submerged. The rails
ing of the water in this way will ma
terially improve navigation. as il
will not only eliminate the canal and
these locks, but will give deeper wa
ter in what are now shallow portions
Of the river above the canal. In .act,
there will be slack water navigation
for a distance of about sixty miles
above the dame at low stage.
The new work includes a single
Jock of 40-foot life which will have
a chamber 4uOx100 feet. with cigh,
feet Of water. Alongside Of the up
per entrance TO the lock is the 10
foot entrance to Il basin loOX46l
feet for dry dock purposes.
The skilled labor working on the
dam is largely American. but the
common laborers are mainly foreign
ers, who are found to be more relia-
bic than Americans of the same class.
and to give less trouble on account
of drunkenness. All crib work is
done by a special force of French
Canadians, who do no other kind OF
work. With the foreign common la
Dor, special care is taken that the
men are properly treated. and each
man is pan his money direct, the
system of having men in charge OF
"padrones."
One reason for the rapid and sys-
tematic progress Of the work is the
organization of the labor. One lot
Of men does nothing but place con-
crete. and consequently becomes very
expert ut this.
Excursions to the Work.
Engineer works rarely receive
much attention on the part OF the
public, but the work at Keokuk
forms a local attraction, the people
OF the surrounding country having a
popular interest in the big dam
acros sthe A4ssissippi,' as the pro-
ject has been in the public eye for so
many years-in fact, excursions arc
run from nearby points to Keokuk,
with the dam as the main attraction.
To meet this condition and still pro
-, r., .,al,l;,v tho nNh,ir from