Atlanta Georgian. [volume] (Atlanta, Ga.) 1912-1939, 1913-09-21

striking clearness how much bigger
the job was than anything engineers
had ever tackled up to ten years ago
The digging of Culebra Cut has, for
one thing, given the engineering world
a new set of standards by which to
measure the requirements of future
works Of a similar character.
II was estimated in the beginning
that 100000 cubic yards of earth
would have to be taken out of the
Culebra Cut, not counting the 24,000,-
600 cubic yards removed by the
French. Yet next spring will see
more than twice that amount of ma
terial dug out of the cut. The original
estimate of the international board of
advisory engineers as to the amount
to be taken out If a sea level canal
were constructed was only 5000, 900
cubic yards in excess nf what has aC-
tually been removed for a lock canal
the bottom of which is As feet above
sea level.
as SheveIs at Work.
II was then estimated that the cut
would accommodate 100 steam SHOW
els in operation Experience has
shown that the maximum number
which could work at one time in the
cut was 46. and no one has ever chided
Colonel Goethals for not digging in
dustriously. Yet had the original es-
innate Of the capacity Of these steam
shovels been verified by experience
the United States would be to-day
looking forward to a celebration of
the opening of the Panama Canal in
1926, instead of in 1914 or 1915. So
great has been the increase of eff
cheney among the canal builders that
even though the estimate of total ex-
cavation has been increased from
time to time until more than 100, 000,
600 cubic yards have been added, not
a single day has been added to the
time required for the digging nor a
single dollar added to the cost. 1t
was largely the men at work in Guile
bra Cut who made possible this vir-
tual gift of 100, 100000 cubic yards Of
excavation thrown into the Job extra.
The slides alone in Culebra Cut
added about 25,000,0O0 cubic yards
to the work of the diggers there. If
all the horses in the United States
were hitched up to wagons contain
ing the material dumped into the cut
by slides they would not be able to
move It an inch. Think Of a farm
of Ct acres sliding downhill into the
partially completed cut at one time
Think of this happening not once but
scores Of times though usually on a
somewhat smaller scale.
Cucurache Oldest Slide.
The Cucurache slide alone has
added 5.O00.0O cubic yards to the eX
slide has brought in more than $780,
900 cubic yards more. The canal en-
gineers have records of more than
score of important slides, great
ma secs Of the banks of the cut which
have been in motion almost ever
since the Americans took up the
business of canal digging.
The Cucurache slide is the Oldest
and the most active Of all the slides,
1t began in July, 1905, when cracks
and assures were noticed far up the
banks of the cut. 1t hasn't stopped
sliding vet and will not until the
slope of the banks has been reduced
sufficiently to tighten the pressure.
There is only one method Of treat
ment of slides. that is to dig the ma
terial out as fast as It slides in. The
canal workers became so accustomed
70 slides that when a million or more
cubic wards Of earth fell into the big
ditch" burying steam shovels and
railroad tracks and sometimes whole
trains 20 feet deep they calmly pro-
Ceeded to dig everything out again
Sometimes the slides moved as rapid
" as four feet in II minutes and
often workmen engaged in digging
out a slide continued at their work
with great danger to their own lives.
Two Causes Responsible.
The biologists have divided the
slides into four kinds, due to two
causes The causes, are first, the
weak and unstable condition of the
rocks of the cut, attributable solely
To nature. and second, the Oversteep
ness and height Of the wall of the cut
the blasting and other works due en-
tirelv to man. The four kinds Of
slides are the structural breaks, the
most common and most difficult to
deal with; the normal or gravity
slides, the fault zone slides, and
fourth. the weathering and erosion
slides. 1t has been found necessary