The evening times. [volume] (Grand Forks, N.D.) 1906-1914, 1906-02-20
THE EVENING TIMES, GRAND FORKS, n. D. (

will contain about 81, 2Qo, 900 cubic
yards Of material, principally the spoil
from the excavation Of the canal
prism. 1t Is provided with ample
spillways and regulating works. "A
channel 500 feet wide at sea level leads
from Limon Bay to the Gatun dam,
where lis placed double flight of
three locks by means of which vessels
are lifted into the artificial lake. The
lake provides unrestricted navigation
for a large part of its length, but be-
comes more contracted as the Conti-
mental Divide is approached until in
the Culebra cut the width at bottom
is reduced to 200 rect. 1t finally ter
inmates at Pedro Miguel, where the
first lock on the Pacific side is placed,
having lift of 80 feet BY means of
this lock vessels are lowered into an
other artificial lake created by dam
closing the valley of the Rio Grande,
and by two other dams closing other
depressions, the level of the lake be-
ing 55 feet above the sea. The crests
of these dams are 80 feet above the
sea. Communication between the lake
and Panama Bay is effected by dou-
BILE flight of two locks placed near the
shore on the high ground called Sosa
Hill. All locks are in duplicate and
have a disable length 900 feet, and
depth over the inter stills 40 feet. The
depth Of the channel is everywhere at
least As feet except in the locks and
In Limon Bay, where 1t Is 40 feet, the
depth in Panama Bay, however, being
measured from mean tide and not
from dead low water. In the lakes the
depth is often very much greater, be-
Ing Is feet near the Gatun dam, and
nearly as much for many miles. The
width is nowhere less than 200 feet
at bottom, and at most places is very
much more. The length of the canal
from deep waite rim Limon Bay to deep
water In Panama Bay Is 1912 miles.
OF this 1871 miles is over 1000 feet
wide, % miles is over 800 feet wide,
IS miles is over 500 feet wide, and 42h
miles Is over 300 feet wide. That is,
for about half the distance navigation
is entirely unrestricted, while for more
than two-thirds the distance the chan
nels are 500 feet or more wide, and
for only one-seventh the distance, in
GLIDING the locks, are they less than
goo feet wide.
The cost Of the canal under this plan
is estimated by the minority of the
board at .$139, 705, 200, and the time re-
qutred to build it at nine years. We
consider both of these estimates rea-
sonable, subject to the remarks al
ready made concerning unit prices.
The plan recommended by the mi
nority of the board is of the same type
as that recommended by the commits
sion of 1S99-1901 and adopted by con-
gress, at least by inference, in the act
approved June 2S, 1902. 1t provides
wider and deeper channels and larger
locks than that plan and different
arrangement of dams, as we'll as
change in the Atlantic entrance, but
the height of the summit level is the
same, and the estimates of cost and
of the time required for construction
are very nearly the same. Some of
the changes have been made necessary
by new requirements for navigation.
and others have been the rsult of fur
Their study by fresh minds. They are
improvements, such as congress could
not possibly have intended to prohibit
when it adopted the cid plan. They
are of Importance, but they do not
seem to us to be changes of such rad
ical character as would require fur
Their action by congress, as in the case
of canal at sea level.
The only features of this plan which
do not fall within the limits of every
day practice are the height and size
of the dams and the size of the locks.
No question has been raised as to the
stability of the Gatun dam, and, in
deed, none can be raised while there
are in successful operation in this
country earth dams of less cross Sec
ton retaining greater head of wa
ter. The great quantity of material
available has made it possible to give
this dam dimensions which are much
greater than are strictly necessary.
The majority of the board, however,
do question the effectiveness of that
dam in retaining water, expressing the
fear that the subfoundation may be
found SO porous that seepage will be
excessive. The minority point out
that the material under the dam is ex-
ceptionably favorable, that for depth
of 200 feet it is practically impervious,
and that the more porous material
which Is found for a short distance be-
low that depth is covered with this
impervious blanket 200 feet thick for
a long distance upstream. They ex-
press the opinion, in which we concur,
that there would be no appreciable
seepage under the dam. In the case
of the Rio Grande dam, the majority
goes further an Estates that the earth
dam proposed for that locality is in
danger of being pushed bodily out of
place by the pressure due to the head
of Water, in the reservoir" unless it
be made very massive. In the opinion
of the minority, in which we concur,
the dam, as designed, is SO massive
that this is impossible. In this case,
the greatest depth to rock is "a feet,
and all seepage can be cut off by sheet
piling, If necessary; but the borings
thus far indicate impervious material
under the dam, and it is not expected
that that device will be required.
The locks are larger than any which
have heretofore been built, and the
majority Of the board express the opin-
ion that they are beyond the limit OF
prudent design. AS matter Of fact,