The daily telegram. [volume] (Clarksburg, W. Va.) 1901-1926, 1913-09-24
By WILLIAM R. ScOTT
CONTINUED from yesterday.)

uluS Ut fhuhula permitted Lue OuuEESS
river to escape into the Caribbean sea
through a break in the mountains at
Gatun. Engineers logically considered
that this was the point at which dam
should be thrown across the Chagres
river. Two valleys were formed at
Gatun by a hill which rose in the
center to an elevation of Ito feet, and
the dam that was designed runs from
the Gatun locks to this hill and from
this hill to the mountains, n total dis
tance of 1900 feet, or a mile and
half
As the chagres river every year dis
charges enough water to ill the lake.
some means of disposing of the sur
plus water had to be provided. The
plan adopted called for 4, sRlliway to
be constructed in this hill about third
way in the dam site This spillway is
of concrete. requiring 225O00 cubic
yards to complete. On July /. 1918, it
was more than 9S per cent completed.
The floor of the spillway is ten feet
above sea level and 800 feet wide
through the hill. which involved ex-
cavation through rock for depth of
100 feet at the Highest point Of the
hill A concrete dam was built on
this floor to a height of sixty-nine feet
above sea level and in shape like
semicircle. On top of the concrete
dam piers We're built with an arrange.
ment for steel gates These steel
gates will be electrically operated and
regulate the flow of water out of the
lake AS much as 10000 cubic feet of
water per second may escape through
the spillway when tile gates are open.
There will not he complete loss of
this water, MS ON the east side of the
sDillway a power plant Of the hydro
electric type will be operated. a drop
Of seventy-five feet by the water will.
operate turbine engines. which III turn
will operate tile electric machinery that
win generate all the power and illumi
hating current needed from one end q
the canal toatheSother. But an addi-.
tional power plant, will be maintained
1t AIirafores. for emergencies. The
power TO operate the lock gates will
come from the spillway plant.
The Gatun dam Is so stupendous that
1t almost seems to be n continuation Of
the hills that inclose the lake. 1t in
fact does complete the natural noun
tain chains that form the barriers of
tbs, chagres river, 1t is 1o5 feet high
or twenty feet above the orc mary level
of the lake at eighty-tive feet eleya
ton. The plan of construction has
been to build parallel mounds for the
mile and half, 1900 feet apart. Be
tween these mounds, built of rock and
earth, core for the dam has been con.
structed by pumping mud and sand
from the bed of Chagres river. About
20 per cent Of the material pumped is
solid matter. and when 1t has deposited
the water is pumped off. This oncrl.
ton has been repeated until - ii.titrr.
vious heart has been made IL tae dam.
Even If water from the lake penetrated
the outside walls of rock and earth ii
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 ton. 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. at
other points to less severe pressure.
Engineers consider the dam exces.
sively safe, and the layman has no diff
fculty in approaching its strength.
About half Of the material required,
22,5O4,0O0 cubic yards, has been
brought from the culebra cut. On July
!, 1913, the dam was more than 90 Der
cent completed, leaving less than / per
cent to be done before the passage of
the first slip.
On the Pacific side the first dam to
be encountered is at Pedro Miguel and
serves to hold the waters of Gatun
lake at its southern end. It is 1 400
feet long and forty feet wide at the
top. The maximum height of the water
against this dam will be forty feet
The plan Of construction is much the
same as at Gntun, but only 1000 900
cubic yards will he required.
After a ship is lowered thirty feet
by the Pedro Miguel lock it finds it.
self in an artificial luke a mile and
half long. This lake is formed by two
dams, the one TO the west being $500
feet long and forty feet wide at the
top, holding maximum head OF wa
ter Of forty feet. It is constructed with
a hydraulic core like the Gatun dam.
On the east a concrete dam 500 feet
long and provided with spillway, as
at Gatun. and capable of dlschargIng
1900 cubic feet of water per second
will hold the small lake in control.
The Cocoi river is the principal feed
er Of this lake.
Records kept by the French and by
the Americans since 1904 show CON
ciusively. that enough water always
will be available to keep the Gatun
lake and the tiny Miraflores lake ade-