Yorkville enquirer. [volume] (Yorkville, S.C.) 1855-2006, 1910-05-10

shaped piece out of 1t down to forty
feet above the sea-the water surface
is to be at eighty-five feet, but the ca
nal will be forty-five feet deep-and to
have the bottom of that slice full 300
feet wide. that is a good deal of job.
One hundred million cubic yards of
rock and dirt, to be exact. One can
hardly realize the magnitude of the
work without seeing it with his own
eyes.
"The French made deep, narrow cut
at Culebra, and took out some 24,OOO,-
900 cubic yards of material. When the
Americans took hold their operations
weren't quite so spectacular. Before
going any deeper they extended the
cut to practically it's full width. That
took several years. Then they started
down. They won't make any official
statements on the isthmus now as to
any probable dates of completion,
but the unofficial statements-and they
are usually as accurate-givc only four
years for the entire completion of the
Culebra work And that and the Ga
tun dam and lock work are the two
points which will be finished last
Between the cut and the Gatun dam
there will have to be little excavation
merely the looping off of few
knolls here and there near the rise of
the continental slope. For the first
eight miles in from Gatun there will be
no digging at all: in and near BaS
| Obispo, at the foot of the hills, the
French did a good deal of eXcavating
which will prove most useful. But for
all of the twenty-three miles of what
| will be open lake the work is to all
| intents finished. The hardest digging
| here was simpler even than the work on
several canals which have been built
in the eastern states. There were a
couple of rivers to control, rivers
which would rise higher than the ca
nal excavations, but it was only mat
ter of two or three feet, and that was
simple.
1.-The key pieces Of the whole canal
are the dams and locks-the dam and
double flight at MirafOres. the twin
| single-lift lock at Pedro Miguel and.
more than both of these, the great
dam and triple flight of locks at Gatun.
The locks throughout the line of the
waterway will be uniform; the two mi
nor dams are but little out of the
ordinary. And so a general description
of the work and progress at Gatun
should give a fair idea of the whole
work.
| "Gatun Is the Atlantic water gate
way of the isthmus. Here it is that
| two or three good sized riverS-the
| Chagres and the Gatuncilla and sever
al others-pour in together and swirl
out between two low-lying ranges Of
hills into the Caribbean. Back of
| Gatun the country spreads out for
miles of bog and swamp and sOgSy
morass, the territory which will form
the bed of the new lake. Nature could
hardly have designed a better place
for gigantic dam and spillway and
flight of locks.
| Across the 800 feet between those
two low ranges the dam is being
when you stand there and look it over
| thrown-a dam 115 feet high and
nothing more or less than big, easy
hill suuarely across the valley. 1t is
neither the largest nor the most spec
tacular dam ever constructed, but
when you stand there and look it over
it seems like a pretty big proposition.
That pile of rock and earth will have
head Of only S5 feet of water against
it, and that for but about 500 feet of
it's length, but it will hold a lake the
area of which will be over 164 square
miles.
Right in tine middle of the valley and
incidentally, of the dam, rises small
hill of rock-Spillway hill, they call it,
because here a concrete lined rock cut
will take care of the surplus water
which the rivers pour down during the
rainy season. The spilway is to have
a channel 800 feet wide, designed for
a run-off capacity of 100000 cubic feet
| a second. That is about finished; the
| cut has been completed, the concrete
floor is down, and the walls themselves
are well under way.
West of Spillway hill little work on
the actual dam construction has been
done: that's because there has got to
be some place for the rivers to run un-
til they can be turned through the
spilway itself. But on the east side
good deal is going on. They started
out by dumping two parallel lines OF
rock, about Twelve hundred feet apart,
from the lock side at Gatun over to
the hill in the centre of the valley.
| On the outside of the rock was dumped
indiscriminate stone and dirt Tney
got those two lines pretty well up like
two separate dams, and then began
filling in the space between with i'm
pervious material pumped in by
dredges. The rock toes" of the east
ern half of the dam are about up to
their full height, but the pumping work
is still going on-continuous streams of
watery mud pouring in day and night.
The water drains off and the sandy clay
| settles, drying SLOWLY anu pdChlilS IL
self so hard by it's own weight that it
becomes almost as solid as concrete.
"When they get that finished-and it
won't be long-tney'll level things off
and riprap the surface where wave ac-
ton will come, and then the work will
be ready for business. The dam. will
stand 80 feet above water. Its top
will be 100 feet wide. At the lake sur
face it will be 39S feet thick, and down
at the bottom more than 1000 feet
through. The slopes are so gentle that
the water pressure will practically all
be down, not out.
"'Why,' said one of the engineers,
that won't be dam. It'll be small
mountain
although the dam at Gatun is no
particular record breaker, except in the
one point of being safer and more