The Bossier banner. [volume] (Bellevue, Bossier Parish, La.) 1859-1952, 1913-12-25


100 feet Mt the highest point of the
Hill A concrete dam was built on
this floor to height Of sixty nine feet
above sea level and In shape like a
semicircle On top OF the concrete
dam piers were built with an arrange
ment for steel gates These steel
gates will be electrically operated and
regulate the Cow Of water out Of the
lake. AS much as 10000 cubic feet OF
water Ger second may escape through
the spillway when the gates are open
There will not be complete loss OF
this water, AS on the east side Of the
spillway power plant Of the hydro
electric type will be operated A drop
OF seventy five feet by the water will
operate turbine engines. which in turn
will operate the electric machinery that
will generate all the power and illumi-
mating current needed from one end Of
the canal to the other But an addi-
tionai power plant will be maintained
at Mirafiores for emergencies The
power to operate the lock gates will
come from the spillway plant.
The Gatun dam is so stupendous that
It almost seems to be q continuation OF
the hills that incfose the lake 1t In
fact does complete the natural noun
tain chains that form the barriers Of
the Cbagres river It Is los feet high
or twenty feet above the ordinary level
Of the lake at eighty FIVE feet eleya
ton The plan of construction has
been to build parallel mounds for the
mile and a half. 100 feet apart Be.
tween these mounds. built OF rock and
earth. u core for the dam has been con.
strncted by pumping mud and sand
from the bed OF Chagres river About
70 per cent Of the material pumped Is
solid matter. and when 1t has deposited
the water Is pumped off This opera
ton has been repeated until an imper
vious heart has been made In the dam
Even ii water from the lake penetrated
| the outside walls of rock aud earth Il
would find this core water tight The
dam is nearly half mile thick at the
| base. 39S feet thick where the water
surface strikes It at eighty five feet
and Is 100 feet wide at the top The
outer coverings of rock and earth on
the dam close over the hydraulic core
at the crest. For about 500 feet the
dam will be subjected to the full pres
sure of eighty five feet of water, ut
other points to a less severe pressure
Engineers consider the dam sexces-
sively safe. and the layman has no dif.
6culty in appreciating its strength
About half Of the material required,
22.504.0OO cubic yards. has been
brought from the Culebra cut. On July
!. 1913, the dam was more than 10 pes
cent completed. leaving less than pei
cent to be done before the passage ot
the first ship
On the Pacific size the first dam t.
be encountered is at Pedro Miguel nnt
| serves to hold the waters OF Gatur
lake at it's southern end. 1t Is l.4Ot
feet long and forty feet wide at til,
top. The maximum height Of the watc
against this dam will be forty feet
The plan OF construction is much til,
same as at Gatun. but only l.OO0.O0l
cubic yards will be required
After ship Is lowered thirty fee
by the Pedro Miguel lock 1t finds 1t
self IN all artificial lake a mile and |
half long. This lake IL formed by tw,
dams. the one to the west being 2.3O
feet long and forty feet wide ut th
top holding a maximum head Of wa
ter of forty feet It il constructed wit
a hydraulic core like the Gatnn dam
On the east a concrete dam 900 fee
long aud provided with spillway. .
ut Gatnn. and capable Of discbargin
7.5OO cubic feet Of water per secon
will hold the small lake In contro
The Cocoli river Is the principal feed
er Of this lake.
Records kept by the French and b
the Americans since 1904 show cor
clusively that enough water alway
will be available to keep the Gatu
lnke and the tiny Miraf1ores lake nd.
quately supplied with water. No tr0s
. BILE at all can develop during the eigt
j months OF rainy season. and In the DR.
season of four months enough waite
will have been stored In the lake
E means Of the regulating works in tt
: Gatun dam spillway to allow for q
i losses through evaporation. seepag
power consumption and loss throue
!. the locks. During the wet season IL
e lake will be raised from elevation
I for two feet to elevation 81 over q
area of 1C;4 square miles This wat,
/ could be used until the lake falls
8 about eighty-two feet. or Eve feet ov'
! the 164 square miles. In an avera1
? dry season this would permit oft
! eight complete transits OF the can
e every twenty four hours II the II
n 1.GW foot capacity Of the locks We
o used or more than the period w0nld
> low IL vessels followed at intervals
I one hour
o The Gatun lake Is backed up amoi
y the bills by the dam until It reaches
d width Of more than twenty miles
the widest point aud length betwe'
!. Gatun and Pedro Miguel Of thirty-tv
. miles. II will be broken by mai
a small islands and stretches Of hil
4 lands and Is narrowest In the Culeb
Il cut, where for nine miles the width
n 800 feet From Gatun to the entran
i OF the cut. a distance Of twenty-ths
Il miles. lighthouses are stationed ut co
g lmanding points to guide ships at mig
Il The channel throughout Is at an av
RI age depth Of forty -dve feet In ORD
= TO raise the relocated Panama rniiro
]. above the level Of the lake It was n
4 cssary to make oils to the extent
1G,425. .292 cubic yards.
i. The navy department has selected
!. site near San Pablo, about twei