Evening star., 1911-10-21

Years to build the pyramid of Cheops
hole deep enough to bury twelve such
pyramids is made in year at Panama.
1t required nearly a score of years to
build the Suez canal; as much dirt is eX-
cavated at Panama in twelve months.
The Manchester ship canal a num-
Der of years in building: that task is du-
plicated in fifteen months at Panama.
1t took the French many years to
discover that they could not build fif-
teen-foot canal as it will take the United
States to make it a finished waterway
forty feet deep, and it cost the French
as much to make failure of their project
as it will cost the United States to make
a success of its undertaking.
Chief Engineer George w. Goethals has
made himself the greatest digger in his
tory In four years he excavated enough
material to make a monument OF DIRT
with a base larger than the height of the
Washington Monument and towering TAR
into the regions of perpetual snow. This
material would fill modern dirt train
long enough to girdle the globe two and a
half times When Uncle Sam took hold
of the work of building the canal 1t was
figured that it would require nine years
to excavate 1O5,OOO,0OO yards of dirt; at
the rate the work is now progressing
he will have moved 165,O00OOO yards IN
five years. The cost of eXcavating yard
of dirt in Culebra cut has been reduced
from 11.5 cents to s.SS cents. The dls,
tance the eXcavated material is hauled
increased from eight to twelve miles III
two years, but the cost of hauling 1t was
reduced from 1854 cents a yard to lo22
cents.
Measured in the results which will fol-
low the completion of the undertaking,
the work at Panama stands in class
by itself. Cities which are today mere
way stations on the international routes
of travel will grow into rich world cen
ters. The east will be broght SeO miles
closer to the west. Eighty million TONS
of freight year may be carried through
the canal without OvertaXing its 1acli-
tiles
The middle section of the canal. thirty
four miles long. has a water level elghty-
five feet higher than the sections from
Gatun and Mirafpres to the sea. Ihe
canal diggers are damming up the Cha-
gres river at Gatun SO as TO make d
great lake, cutting a great ditch through
the Culebra mountain SO as to permit
the water of this lake to back up to
depth of forty feet through the mountain.
This requires a dam at Gatun which VIII
make the lake eighty-five feet deep at
that point. This dam is approximately
"a mile and half long, half mile vide
at the bottom, 100 feet wide at the water
line and Roo feet wide at the top. Its
total height will he 10 feet, or thirty Ieet
higher than the surface of the water IN
the lake II creates. II covers -oo aci G"
of land.
It's slope is so gradual as hardly to be
noticed in the landscape. Take yard
stick and raise one end three inches htgh-
er than the other. and the resulting
sIope will be considerably sleeper than
the average slope of the Gatun dam.
When completed the dam Will contain
some 2O,OW,0,U yards of material, when
is being put into place at the rate OF
more than 5.Cy0,0Oo yards year. con-
h1tl r.
alle lines of stone retaining walls across
the valley. loo feet apart. Between
these two walls millions of cubic yards
of sand and clay are being pumped into
large ponds maintained at the crest OF
the dam. The water deposits its load OF
solid matter and flows off, to be pumped
up again with another load. The natural
cement held in suspension by the dredged
water tightens up every tiny space as
brick mason might close hole In the
wall
One of the problems which the engi-
neers have had to encounter In building
the Gatun dam is that of disposing of
the vast amount of surplus water which
comes down the Chagres. This is a
moody stream. sometimes quiet and shall
low and at other times a torrential river
with a sustained flow of $4,000 cubic feet
of water a second How to build spill
way that will pass such an enormous
amount of water from the lake surface to
sea level. eighty-five feet below has been
difficult problem to solve. The lake
has been made big, covering l64
square miles of superficial surface, that
the Chagres on it's greatest rampage
hours and yet raise it's level only one
foot: the water level may be raised
seven feet without doing damage.
The Chagres now crosses the line of
ty-three-mile journey from Gamboa
where it first strikes the big waterway,
to Gatun. When the Gatun dam is
completed the river will lose itself in the
waters of the lake at Gamboa. The spill
way over which the surplus water Of the
Gatun lake will flow consists of huge
crescent-shaped dam of concrete sur
mounted by thirteen large piers and two
big abutments, which divide the dam into
fourteen openings, each of which will be
opened and closed by giant gates.
Almost every method of excavating
known to the engineering world is
brought into use in digging the Panama
canal At the entrance on each side of
dredges collect the material and carry it
out to sea- On each side of one of these
dredges are huge twenty-inch suckers,
operated by centrifugal pumps, which
work with such tremendous suction pow
er that they pick up such things as pieces
of anchor chains
In the Culebra cut the steam shovel is
king, and dynamite by the carload is
plosives are fired off every month in the
canal works, the major portion of which
is used at Culebra. In some of the big
blasts twenty-five or more wells are dug
by machines operated by the largest air
COMPRESSOR plant in the world, and into
each of these holes the major portion of
a ton of dynamite is placed, and then
the whole thing is touched off by press
ing an electric button.
In another place hydraulic excavation
is resorted to. Here one sees a great
pumping station, capable of forcing 10000
gallons of water minute through a pipe
which tapers from forty to sixteen inches
in diameter. To this are attached four
or five flexible water nozzles, through
which are forced streams of water from
four to six inches in diameter, with a
pressure of 130 pounds to the square
inch These streams of water literally
eat the dirt away.
The canal would be of no use were
there not method of getting ships from
the sea level to the lake level eighty
five feet above and vice versa. To ac-
complish this purpose giant marine stair
ways are being built. These are con-
structed like a double-track railway, SO
that one ship may be- going up while
another is going down. There are three
steps in the stairway at Gatun on the
Atlantic side On the Pacific side there is
one step at Pedro Miguel and there are
two at Mirafores. At each step a ship is
lifted up or down slightly more than
twenty-eight feet The two side-by-side